Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Abstract

If ideal 2D polymer (2DP) macromolecules with small pores that are similar in size to gas molecules, large areas, small thickness, and excellent membrane‐forming ability are synthesized, ultimate gas separation membranes would be obtained. However, as far it is known, such ideal well‐characterized 2DP macromolecules are not isolated. In this study, an ideal 2DP macromolecule is synthesized by using the successive three reactions (Glaser coupling, SCAT reaction, and the introduction of octyl groups), in which the conjugated framework structure is maintained, from a fully conjugated 1D polymer. Because this exfoliated 2DP is soluble, the macromolecular structure can be fully characterized by ¹H‐NMR, GPC, SEM, AFM, and its dense membrane with no defects can be fabricated by the solvent cast method. This soluble 2DP macromolecule has very small micropores (6.0 Å) inside the macromolecule, a large area (30 × 68 nm by SEM and AFM), high molecular weight (Mn = 2.80 × 10⁵ by GPC), and a small thickness (4.4 Å by AFM). This membrane shows the highest oxygen permselectivity exceeding Robeson's upper line because of the high molecular sieving effect of the controlled small micropores.

DOI： 10.1002/smll.202308050

researchmap

Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

DOI： 10.1246/cl.230341

researchmap

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.2c02601

researchmap

Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

DOI： 10.1246/cl.230006

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2022.125622

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1038/s41428-022-00752-7

researchmap

Other Link： https://www.nature.com/articles/s41428-022-00752-7

Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/pi.6440

researchmap

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/pi.6440

Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

DOI： 10.1246/cl.220333

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2022.125092

researchmap

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.macromol.2c00596

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2022.124726

Scopus

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2022.124673

Scopus

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/chir.23404

researchmap

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/chir.23404

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2021.124347

researchmap

Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Oxygen/nitrogen permselective membranes play particularly important roles in fundamental scientific studies and in a number of applications in industrial chemistry, but have not yet fulfilled their full potential. Organic polymers are the main materials used for such membranes because of the possibility of using sophisticated techniques of precise molecular design and their ready processability for making thin and large self-supporting membranes. However, since the difference in the properties of oxygen and nitrogen gas molecules is quite small, for example, their kinetic diameters are 3.46 Å and 3.64 Å, respectively, the architectures of the membrane macromolecules should be designed precisely. It has been reported often that oxygen permeability (PO2) and oxygen permselectivity (α = PO2/PN2) have trade-off relationships for symmetric membranes made from pure polymers. Some empirical upper bound lines have been reported in (ln α − ln PO2) plots since Robeson reported an upper bound line in 1991 for the first time. The main purpose of this review is to discuss suitable macromolecular structures that produce excellent oxygen/nitrogen permselective membranes. For this purpose, we first searched extensively and intensively for papers which had reported α and PO2 values through symmetric dense membranes from pure polymers. Then, we examined the chemical structures of the polymers showing the top performances in (ln α − ln PO2) plots, using their aged performances. Furthermore, we also explored progress in the molecular design in this field by comparing the best polymers reported by 2013 and those subsequently found up to now (2020) because of the rapid outstanding growth in this period. Finally, we discussed how to improve α and PO2 simultaneously on the basis of reported results using not only symmetric membranes of pure organic polymers but also composite asymmetric membranes containing various additives.

DOI： 10.3390/polym13173012

researchmap

Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

DOI： 10.1246/cl.210306

researchmap

Publishing type：Research paper (scientific journal)   Publisher：The Chemical Society of Japan  

DOI： 10.1246/cl.210341

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2021.123857

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2021.123900

researchmap

Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Three new phenylacetylene monomers having one or two carbamate groups were synthesized and polymerized by using (Rh(norbornadiene)Cl)2 as an initiator. The resulting polymers had very high average molecular weights (Mw) of 1.4–4.8 × 106, with different solubility and membrane-forming abilities. The polymer having two carbamate groups and no hydroxy groups in the monomer unit showed the best solubility and membrane-forming ability among the three polymers. In addition, the oxygen permeability coefficient of the membrane was more than 135 times higher than that of a polymer having no carbamate groups and two hydroxy groups in the monomer unit with maintaining similar oxygen permselectivity. A better performance in membrane-forming ability and oxygen permeability may be caused by a more extended and flexible cis-transoid conformation and lower polarity. On the other hand, the other two new polymers having one carbamate group and two hydroxy groups in the monomer unit showed lower performances in membrane-forming abilities and oxygen permeabilities. It may be caused by a very tight cis-cisoid conformation, which was maintained by intramolecular hydrogen bonds.

DOI： 10.3390/membranes10090199

researchmap

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acsmaterialslett.0c00178

researchmap

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acsapm.9b01111

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Elsevier BV  

DOI： 10.1016/j.polymer.2019.122081

researchmap

Publishing type：Research paper (scientific journal)  

© 2019 by the authors. Four kinds of newly synthesized achiral phenylacetylenes bearing a phenylhydrogalvinoxyl residue at 4-position were polymerized by using a chiral rhodium catalyst system, [Rh(nbd)B(C6H5)4] or [Rh(nbd)Cl]2 catalysts in the presence of chiral (R)-(+)- or (S)-(-)-1-phenylethylamine ((R)- or (S)-PEA) cocatalysts. Poly(m-HGDHPA) and poly(m-HGTHPA) in THF showed Cotton signals at the absorption regions of the main chain and hydrogalvinoxyl in the circular dichroism (CD) spectra. It indicated that excess of one-handed helical polyacetylene backbone was induced by helix-sense-selective polymerization (HSSP) under the asymmetric conditions despite the achiral monomer, and the hydrogalvinoxyl moieties were also arranged to form one-handed helical structure. However, there was no Cotton effect for poly(p-HGDHPA) and poly(p-HGTHPA) because the intramolecular hydrogen bonding did not act well to stabilize the helical conformation. The hydrogalvinoxyl units of poly(m-HGDHPA) and poly(m-HGTHPA) were converted to the corresponding galvinoxyl radicals after treatment with PbO2. In the CD spectra of the polyradicals, the Cotton effects decreased depending on their static stability of helical conformation, suggesting that reversal conformation of the polymer chain arose.

DOI： 10.3390/polym11111877

Scopus

researchmap

© 2019 The Chemical Society of Japan. 2,7-Substituted 9,10-bis(phenylethynyl)anthracenes with bulky phenol residues were synthesized and investigated for their antiparallel molecular arrangement. UV-vis absorption and photoluminescence properties and molecular mechanics calculation indicate that they formed an antiparallel π-π stacked dimer, which was strongly associated by hydrogen bonding and π-π interaction. This strongly associated dimer structure was supported by AFM images of specimens prepared on mica by spin casting dilute chloroform/hexane (2/8 v/v) solution. However, the absence of intradimer hydrogen bonding resulted in the offset stacking, which was confirmed from the single crystal X-ray analysis.

DOI： 10.1246/bcsj.20190156

Scopus

researchmap

DOI： 10.1246/cl.190109

Web of Science

researchmap

DOI： 10.3390/nano9060859

Web of Science

researchmap

DOI： 10.1016/j.polymer.2019.03.039

Web of Science

researchmap

DOI： 10.3390/polym11020274

Web of Science

researchmap

DOI： 10.1016/j.polymer.2018.09.048

Web of Science

researchmap

DOI： 10.1016/j.polymer.2018.09.009

Web of Science

researchmap

DOI： 10.1246/cl.180641

Web of Science

researchmap

© 2018 Elsevier Ltd Copoly(4-dodecyloxyl-3,5-dihydroxymethyl-phenylacetylene/p-pinanyldimethylsilylphenylacetylene) (copoly(1/2)) consist of both the cis-cisoidal sequence of achiral 4-dodecyloxyl-3,5-dihydroxymethyl-phenylacetylene (1) and cis-transoidal sequence of chiral p-pinanyldimethylsilylphenylacetylene (2). The reactivity ratios of 1 and 2 in the copolymerization were estimited as r 1 = 1.49 and r 2 = 0.50, respectively. By replacing THF (a good solvent) of copoly(1/2) solution with methanol (a poor solvent) gradually by concentration-driven permeation through a membrane for several times, stepwise increase in the CD intensity at 308 nm arisen from the cis-cisoidal main-chain was observed. The local chirality in chiral 2 units was successfully transmitted to the cis-cisoidal sequence of achiral 1. Even when the molar ratio of 1/2 reaches 50, this method of the multiple-stage-solvent-exchange is still effective for transmitting the local chirality in 2 to the cis-cisoidal sequence 1 in the copolymer. Directly adding methanol to the copoly(1/2)'s solution and annealing of copoly(1/2) in THF/methanol could not realize this chiral teletransmission. Hence, this new method of the multiple stage solvent exchange in the copolymer solution through a membrane is suitable and efficient to realize the efficient chirality transmission and amplification in the cis-cisoidal polyacetylene.

DOI： 10.1016/j.polymer.2018.09.023

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier B.V.  

Six new silicon-containing phenylacetylenes having short oligosiloxane substituents with different sizes and shapes have been synthesized. Homopolymerization of the monomers yielded the corresponding homopoly(substituted phenylacetylene)s with high molecular weights and good solubility. These comb-shaped homopolymers gave self-standing membranes whose PO2 and PO2 /PN2 could be measured. We discuss the effect of the chemical structures on their membrane performances together with the other seven related polymers we synthesized before and commercially available cross-linked polydimethylsiloxane (PDMS). While the homopolymers with linear oligodimethylsiloxanes (ODMS) show very high PO2 values which are higher than PDMS, the homopolymers with branched ODMS show high PO2 /PN2 values which are close to that of poly(phenylacetylene) (poly(PA)) and, in addition, had ten times higher PO2 than poly(PA). Introduction of the branched spherical ODMS substituents increases PO2 without any drop of PO2 /PN2 and introduction of the linear ODMS substituents increases PO2 largely which is higher than that of PDMS. It was found that the chemical structures, i.e., the shapes of the ODMS substituents were more important than that of composition for determining their performance as oxygen permselective membrane materials. In conclusion, oxygen permeation could be tuned by changing sizes and shapes of the ODMS side groups.

DOI： 10.1016/j.memsci.2018.04.031

Web of Science

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.polymer.2018.06.075

Web of Science

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.1080/15685551.2018.1472720

Web of Science

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1038/s41428-018-0045-7

Web of Science

Scopus

researchmap

Other Link： http://www.nature.com/articles/s41428-018-0045-7.pdf

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Elsevier Ltd  

Selective photocyclic aromatization (SCAT) of cis–cisoid helical poly(phenylacetylene) derivatives was investigated during the in situ photodegradation in a film. An infrared absorption peak appeared at ∼1700 cm−1 owing to the overtone vibration of the 1,3,5-trisubstituted benzene and the peak at 1060 cm−1 due to the cis C=C bending of the main chain decreased, indicating occurrence of SCAT. Simultaneously, the polymer film became emissive in visible region during SCAT. The fluorescence (FL) quantum efficiency was approximately 0.92% in the film and not so much high relative to usual fluorophores. The FL emission disappeared in an instant when the decomposition product dissolved in a solvent. The FL lifetime of the polymer film increased with photodegradation. These all indicated the occurrence of excimer emission. A finely resolved FL image pattern was readily obtained using a photomask.

DOI： 10.1016/j.dyepig.2017.10.035

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley-VCH Verlag  

A brand new, soluble quadruple-stranded copolymer is synthesized by using a self-template polymer from a new monomer. In addition, another very unique quadruple-stranded copolymer having a π−π stacking supramolecular polymer main chain is synthesized by selective photocyclic aromatization of the quadruple-stranded copolymer. The two quadruple-stranded copolymers gave self-standing membranes.

DOI： 10.1002/marc.201700556

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Since highly selective photocyclic aromatization (SCAT) of poly(substituted acetylene) s yields quantitatively the corresponding 1,3,5-trisubstituted benzene derivatives, the SCAT products were applied for quantitative determination of microstructures of copoly(substituted acetylene) s by NMR (nuclear magnetic resonance). By this SCAT-NMR method for two copolymers of two different types of substituted acetylenes, quantitative analysis for microstructures, i. e., triad distributions and compositions, have been achieved successfully under mild conditions, although they could not be obtained from the NMR of the original copolymers because of their broad and overlapped peaks.

DOI： 10.1246/cl.170697

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Chiral compounds play a vital role in our lives because we are made up of chiral polymers. A strict rule of chirality synthesis is "to obtain one enantiomer of a new chiral product, one enantiomer of a chiral source is needed". If two enantiomers can be synthesized using a single chiral compound, we can both break the above rule and open up a more efficient route to useful chiral materials using a cheaper chiral source. Here we report the first example of double reversals of enantioselectivity in catalytic asymmetric polymerization of achiral monomers using a single isomer of simple chiral compounds as cocatalyst. Furthermore, we achieved this by changing only one achiral condition, that is, the amount of the chiral cocatalyst, without any other changes in the polymerization conditions. As a result, we easily and directly synthesized (+)- or (-)-polymer using a single chiral compound as a cocatalyst.

DOI： 10.1021/acs.macromol.7b01671

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

In order to estimate oxygen permselectivities through a supramolecular polymer membrane for the first time, we prepared three kinds of composite membranes consisting of a supramolecular polymer membrane and a conventional organic polymer membrane. Supramolecular polymer membranes were prepared by using highly selective photocyclic aromatization of poly(substituted acetylene)s. It was found that the supramolecular polymer membrane had oxygen permselectivity (alpha = P-O2/P-N2) around three in spite of its low molecular weight. (C) 2017 Published by Elsevier Ltd.

DOI： 10.1016/j.polymer.2017.08.066

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Novel well-defined complex,polymers, polymers of acetylene type macronionomers having silylene-vinylene-phenylene-ethynylene hyper-branches, investigated as a new class of subnanoporous oxygen permselective membrane materials, were synthesized very easily by one-pot Simultaneous two-mode homopolymerization of a single monomer with a single catalyst. For this "simultaneous polymerization" we synthesized AB(2)-type monomers (1,3-bis(dimethylsilyl)phenylacetylenes) containing one terminal triple bond and two Si-H groups. The resulting poly(hyperbrancIed mactornonomer)s had high molecular weights, low densities, high solubility, and good self-membrane forming ability. They had higher oxygen permselectivities (a = P-O2/P-N2) than any other reported polymers having similar oxygen permeabilities (P-O2). These excellent polymer membranes could be obtained only by the simultaneous polymerization. In the one-pot simultaneous polymerization, the two different modes of polymerizations, i.e., addition polymerization of the triple bond and polyaddition of the triple bond and two SiH groups in the single monomer, occurred simultaneously by using one catalytic system, i.e., [Rh(norbornadiene)Cl](2)/various amines. The ratio of the branches (RB), i.e., the addition polymerization and the polyaddition, could be controlled by changing the amine cocatalysts. Their oxygen permselectivities could be adjusted by controlling the polymer structures including RB.

DOI： 10.1021/acs.macromol.7b01458

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

New types of multi-bridged copolymers were designed and examined as oxygen permselective membrane materials. The multi-bridged copolymers were synthesized by imine metathesis reactions between N-imine (synthetic equivalent of amine)containing poly(substituted acetylene)s and C-imine (synthetic equivalent of aldehyde)-containing poly(substituted acetylene) s in the membrane state. The resulting copolymers maintained good self-membrane forming ability. The introduction of multibridge structures enhanced both oxygen permselectivities and oxygen permeabilities simultaneously.

DOI： 10.1246/cl.161104

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

One of the authors discovered helix-sense-selective polymerization (HSSP) of an achiral substituted phenylacetylene which has two hydroxymethyl groups and a relatively hydrophobic substituent by using a chiral catalytic system in 2003. The one-handed helicity is stable and static in nonpolar solvents because it is maintained by intramolecular hydrogen bonds. Since the resulting polymer has extremely tight helicity in its main chain, it shows many interesting and unusual properties including highly selective photocyclic aromatization (SCAT). In this review, the discovery and development of the HSSP and SCAT reactions, and the properties and application of the resulting polymers prepared by HSSP and the resulting supramolecular polymers prepared by SCAT will be examined.

DOI： 10.1080/15583724.2016.1160930

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Both cis- and trans-rich poly[p-(trimethylsilyl)phenylacetylene]s (PTM-SPAs) were synthesized using [Rh(norbornadiene)Cl](2)-TEA (TEA: triethylamine) and WCl6-Ph4Sn as catalysts, respectively. The Rh-based cis-rich polymer exhibited a remarkable fluorescence (FL) emission enhancement after thermal annealing (heating at 200 degrees C in N-2 atmosphere for 1 min), while the pristine polymer was almost entirely non-emissive. NMR and Raman spectroscopic studies clarified the occurrence of irreversible cis-trans isomerization under thermal annealing and suggested that the FL emission increased with an increase in the trans content of PTMSPA. Computer simulations of 12-mer model compounds clarified that the FL emission is a result of intramolecular excimers formed from side-on -stacking of phenyl groups, which is possible only along the backbone of the trans-based polymer.

DOI： 10.1080/15421406.2016.1277910

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

By using a living one-handed helical cis-transoidal poly(chiral substituted phenylacetylene) as a polymer initiator (poly(I-n)), helix-sense-selective polymerization (HSSP) of an achiral phenylacetylene 2 having two hydroxy groups successfully afforded a diblock copoly(phenylacetylene) (copoly(I-n/2(m))) consisting of a dynamic one-handed helical cis-transoidal block and a static one-handed helical cis-cisoidal block. The formation of the diblock structure was confirmed by consumption of the chiral initiator, appearance of characteristic CD indicating the one handed helical cis-cisoidal block, and occurrence of the selective photocylic aromatization reaction in the cis-cisoidal block. Therefore, HSSP has been achieved by using the chiral alkenyl groups in the initiator as a chiral source for the first time. In addition, since the HSSP was achieved in spite of the long distance between the chiral initiation site and the propagating site, chiral teleinduction through the rigid and static one-handed helical cis-cisoidal block based on domino effects was confirmed.

DOI： 10.1021/acsmacrolett.6b00809

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

We synthesized six phenylacetylenes (RCOPAs, RSOPAs, and RSPAs) having a bulky fused polycyclic aliphatic group, which is adamantyl(Ad), pinanyl(Pi), or cholesteryl(Ch) via oxycarbonyl (CO) or oxydimethylsilyl( SO), and the other two phenylacetylenes having less or non-bulky substituents, i.e., menthyloxycarbonylphenylacetylene (MtCOPA) or ethoxydimethylsilylphenylacetylene (EtSOPA) (Et = Ethyl). The new monomers were polymerized and copolymerized with p-trimethylsilylphenylacetylene (SPA) by using catalyst [ Rh(nbd)Cl](2) (nbd = 2,5-norbornadiene) in trimethylamine to give soluble high molecular-weight polymers in relatively good yields. The resulting copolymers were fabricated to self-supporting membranes which had enough strength for separation membranes by solution casting method. As a result, we can discuss the relationship between bulky chemical structures and permeation behavior systematically for the first time. Oxygen permselectivities (PO2/PN2) of copolyRSOPAs having the bulky fused polycyclic aliphatic groups such as Ad and Pi were higher than those of copolyEtSOPAs. PO2/PN2 values of copolyRCOPAs were higher than those of polyRSOPAs when they had the same content of the identical bulky groups. The rigid spacer was effective for enhancing PO2/PN2. Among copolyRCOPAs with bulky fused polycyclic aliphatic groups, the copolymers with spherical substituents such as Pi and Ad groups showed higher PO2/PN2 values than those with a planer substituent i.e., Ch groups. PO2 values of copolyRSOPAs and copolyRCOPAs were 130-220 and 50-90 barrer, respectively. The flexible silyloxy spacers in RSOPAs were effective in enhancing their PO2 values. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2016.07.023

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Two novel chiral well-defined rhodium complexes, Rh(cod)(L-Phe) (cod=1,5-cyclooctadiene, Phe=phenylalanine) and Rh(cod)(L-Val) (Val=valine) were synthesized, isolated by recrystallization, and characterized. The helix-senseselective polymerization (HSSP) of an achiral 3,4,5-trisubstituted phenylacetylene, p-dodecyloxy-m, m-dihydroxyphenylacetylene (DoDHPA) was examined by using the two Rh complexes as catalysts. These catalysts provided high molecular weight polymers (M-w 28 x 10(4)-45 x 10(4)) in about 40%-85% yields. The resulting polymers exhibited a bisignated CD signal at about 300 nm and a broad signal around 470 nm, indicating that they have preferential one-handed helical structure. The present catalysts achieved larger molar ellipticity up to [theta](310) = 13.0 x 10(4) deg cm(2)/dmol than those with binary chiral catalytic systems, [Rh(cod)Cl](2)/(L-phenylalaninol), [Rh(cod)Cl](2)/(L-valinol), and [Rh(nbd)Cl](2)/(R)-PEA. All these results manifest that the present, well-defined Rh complexes serve as excellent catalysts for the HSSP of DoDHPA. (C) 2016 Wiley Periodicals, Inc.

DOI： 10.1002/pola.28106

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Highly selective photocyclic aromatization (SCAT) of poly(substituted acetylene)s, which can quantitatively yield the corresponding 1,3,5-trisubstituted benzene derivative, was applied to quantitative determination of the microstructures of copoly(substituted acetylene)s. By GPC analysis of the SCAT products of the copolymers of two substituted acetylenes having substituents whose molecular weights were greatly different, some clear information regarding the microstructures, such as sequence (triad) distribution and composition, which could not be obtained from NMR because of their broad peaks, could be obtained successfully under a mild condition.

DOI： 10.1246/cl.160357

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A highly emissive, optically active poly(diphenylacetylene) derivative, NpSi*-PDPA, was synthesized by introducing a bulky chiral pendant group into the polymer chain. NpSi*-PDPA exists in a glassy state having a highly disordered and amorphous structure. Hence, the fractional free volume is quite high, i.e., 0.29. NpSi*-PDPA emits a green light in solution and a yellow light in film. This polymer is quite emissive, as the photoluminescence (PL) quantum yield is 56.1% in solution and 6.2% in film, and the PL lifetime is relatively long, 1.71 ns in solution and 1.05 ns in film. NpSi*PDPA shows the strongest circular dichroism (CD) signal at 384 nm, with a magnitude of circular polarization (g(CD)) of 0.90 x 10(-3) and an optical rotation of 110 degrees (4.30 X 10(-3) g mL(-1), in CHCl3). The CD intensity is significantly increased by annealing at 80 degrees C, reaching an equilibrium at g(CD) of 7.10 X 10(-3) after 72 h.

DOI： 10.1021/acsmacrolett.6b00184

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Commercially available molecular rotor (MR) compounds were recrystallized using chiral monoterpenes as solvents. The resulting crystals exhibited large circular dichroism signals with opposing signs according to the handedness of the chiral solvent used. X-ray crystallographic analysis showed that the chirality originated from asymmetric restriction of intramolecular rotation in the crystals. The crystals were also highly emissive due to restricted bond rotation, while solutions of the materials were almost nonemissive. The solvent-to-MR chirality transfer approach to. crystallization discussed herein should be a convenient, universal way to obtain highly emissive chiral crystals.

DOI： 10.1021/acs.cgd.6b00128

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A novel soluble well-defined ladder polysiloxane bridged by imido linkages having a high molecular weight was successfully synthesized via the corresponding supramolecular intermediate and was fabricated to a very flexible self-standing membrane. The membrane showed a better oxygen permselectivity than conventional linear polyorganosiloxanes. We directly observed the effect of the regular molecular-sized pores formed by the ladder structure on the oxygen permselectivity for the first time. This is the first report on gas permeability thorough a well-characterized ladder polymer.

DOI： 10.1246/cl.151196

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The chain rigidity, liquid crystallinity, absorptivity, and photoluminescence of a helical poly(phenylacetylene) derivative varied significantly depending on the solvent employed, owing to the conformational changes caused by the formation or destruction of intramolecular hydrogen bonds. The polymer chains were rigid and liquid crystalline when dissolved in such non-solvents as toluene and THF to show lower absorptivity and intramolecular excimer emission while the same polymer chains became flexible in piperidine having a high hydrogen-bonding acceptor strength to exhibit strong absorption in the visible region and the emission was significantly quenched.

DOI： 10.1039/c6ra01940d

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A novel achiral phenylacetylene having a bulky t-butyl group was synthesized and polymerized by a chiral catalytic system containing [Rh(nbd)Cl](2) (nbd: norbomadiene) and chiral amines to yield a one-handed helical polymer having a much higher g value than polymers with no bulky groups. Highly efficient helix-sense-selective polymerization has been achieved using a bulky monomer and a less bulky chiral cocatalyst.

DOI： 10.1246/cl.150863

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Poly(diphenylacetylene) membranes having perfluoroalkyl groups were quantitatively synthesized via a three-step membrane reaction, that is, desilylation (the 1st step), Williamson reaction (the 2nd step), and Click reaction (the 3rd step). The conversions of the all reactions were confirmed by IR. spectra and elemental analysis. Even though the reactions were carried out in membrane state, the conversions were fairly high. These high conversions are attributed to high swelling property of poly(diphenylacetylenes), including the extremely large fractional free volume. The gas permeability and thermal property of the perfluoroalkylated poly(diphenylacetylene) membranes were investigated. Polymer reactions are a very useful and powerful

DOI： 10.1246/cl.150841

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We synthesized new 3,5-bis(hydroxymethyl)phenylacetylene (HPA) monomers connected with a rigid and linear pi-conjugated oligomer. The monomers were successfully polymerized with a rhodium catalyst [Rh(nbd)Cl](2) in the presence of chiral PEA to give the corresponding polymers. Helix-sense-selective polymerization proceeded for DBHPA. CD, UV, and WAXS spectroscopic studies revealed that the intramolecular hydrogen bonds of the polymers contributed to the stabilization of their helical conformation but the stability depended on the length of the rigid and linear pi-conjugated side group.

DOI： 10.1246/cl.150616

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

A novel phenylacetylene monomer having a perfluorinated alkyl group (M-F) was synthesized and polymerized in a chiral catalytic system to yield a one-handed helical polymer. The ability and efficiency of the chiral induction of the fluorine-containing monomer in the helix-sense-selective polymerization (HSSP) was much higher than those of a monomer having the corresponding alkyl group (M-H) we reported before. The resulting polymer P-F showed cis-cisoidal one-handed helical conformation, and was suitable for highly selective photocyclic aromatization (SCAT) to give a 2D surface modifier (T-F). Oxygen permselectivity through a base polymer membrane was highly enhanced from 1.83 to 2.36 by adding a small amount (1-5wt%) of the 2D surface modifier T-F. The improvement was thought to be caused by improvement of solution selectivity on the membrane surface which the 2D surface modifier effectively covered. Chirality 27:459-463, 2015. (c) 2015 Wiley Periodicals, Inc.

DOI： 10.1002/chir.22441

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

One-handed helical polyphenylacetylenes having achiral amino alcohol moieties, but no chiral side groups, were synthesized by the helix-sense-selective copolymerization of an achiral phenylacetylene having an amino alcohol side group with a phenylacetylene having two hydroxyl groups. Since the resulting helical copolymers were successfully utilized as chiral ligands for the enantioselective alkylation of benzaldehyde with diethylzinc, we can conclude that the main-chain chirality based on the one-handed helical conformation is useful for the chiral catalysis of an asymmetric reaction for the first time. The enantioselectivities of the reaction were controlled by the optical purities of the helical polymer ligands. In addition, the polymer ligands could be easily recovered by precipitation after the reaction. Chirality 27:454-458, 2015. (c) 2015 Wiley Periodicals, Inc.

DOI： 10.1002/chir.22455

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We found that the helix-sense-selective polymerization (HSSP) of achiral phenylacetylenes having two hydroxy groups was realized by using one-handed helical poly(phenylacetylene)s as chiral cocatalysts prepared by HSSP of the same or similar achiral phenylacetylenes having two hydroxy groups. In other words, the chirality caused only by the one-handed helical backbone was found to be able to work as a cocatalyst in the chiral catalytic system. In addition, the efficiency of the chiral induction was high and almost the same as that of the HSSP by using enatiomerically pure phenylethylamine as a cocatalyst.

DOI： 10.1246/cl.141079

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A one-handed helical cis-cisoidal polyphenylacetylene (P) is successfully synthesized by an asymmetric-induced polymerization of a chiral-substituted phenylacetylene having two hydroxymethyl groups. Quantitative photocyclic aromatization of P in a membrane-state followed by in situ removal of the chiral substituents affords a one-handed helical supramolecular polymer membrane of the corresponding cyclic trimer (T) with no chiral substituents. The original one-handed helicity of the precursor P is successfully transmitted to the resulting supramolecular helicity of de-T. Both the hydrogen bonds and the pi-pi stacking are thought to contribute to the retention of the chirality during the two-step reaction in the membrane state.

DOI： 10.1002/macp.201400526

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Three types of homopolymerizations of p-(dimethylsilyl)-phenylacetylene (HSPA) having a terminal triple bond and a Si-H group were selectively carried out by using three kinds of polymerization catalysts. Among them poly(HSPA) synthesized by addition polymerization of its triple bond using [Rh(nbd)Cl](2) (nbd: norbornadiene)/phenylethylamine (PEA) showed a good membrane forming ability. The copolymerizations of HSPA with p-(trimethylsilyl)phenylacetylene (SPA) were carried out using [Rh(nbd)Cl](2)/PEA and the resulting copolymers were fabricated to self-supporting membranes. These membranes, including the homopolymer of HSPA, showed higher permselectivities for oxygen and carbon dioxide over nitrogen than those of poly(SPA). Incorporation of HSPA unit to poly(SPA) effectively enhanced its permselectivities with only small decrease in its permeability.

DOI： 10.1246/cl.140928

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS INC  

Although two-dimensional polymers (2DPs) and related materials are very attractive subjects for research because they are expected to function as ideal gas separation membrane materials, we need to answer some basic questions about them. For example, "Why are they not a common or popular topic, especially in textbooks?"; "How can they be synthesized?"; and "Whatever are 2DPs? and "How can we define 2DPs?" In this review, we try to answer these questions. First, the significance of 2DP as molecular-sieving membrane materials is explained in Section 1. Second, the definitions and classifications are proposed that take into account their first-order and high-order structures in Section 2. Third, syntheses and function of a few real 2DPs and many related polymers described in the literature are reviewed, including such materials as covalent organic frameworks(COFs), carbonized molecular sieving membranes(CMSMs), polymers of intrinsic porosity(PIM), and our recent results on the synthesis and function of 2DPs and related polymers in Sections 3 and 4. Finally, in Section 5 we evaluate the two-dimensional (2D) characters of 2DPs described in Section 3 using some 2D characteristic values defined in Section 2, and the future of 2DPs is discussed in Section 6.

DOI： 10.1080/15583724.2014.963235

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Three novel phenylacetylenes having two hydroxyl groups via different kinds of spacers between the two hydroxyl groups and benzyl group were synthesized and polymerized. Two of the resulting polymers having oxyalkylene spacers between the hydroxyl group and benzyl group had good membrane forming ability, relatively high oxygen permselectivity and high oxygen permeability. By introducing the oxyalkylene spacers, the membrane forming abilities and oxygen permselectivity were enhanced. Oxygen permselectivity (P-O2/P-N2 = 2.67) of the polymer membrane having the longest spacers was higher than that (2.19) of polymer without any spacers. It may be because the columnar content and then defects decreased when the cis-cisoid conformation was changed to cis-transoid conformation. In addition, by decreasing the columnar content of the membrane from the polymer without any spacers, which could be controlled by conditions in membrane preparation, the membrane forming ability and oxygen permselectivity were effectively enhanced (from 2.19 to 2.61) without any drop of oxygen permeability. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2014.11.042

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Helix-sense-selective polymerisation of three new achiral substituted acetylenes containing two bulky pi-conjugated planar substituents via imino groups by using catalytic amounts of a chiral source yielded soluble and statically stable one-handed helical polymers which were stabilized by intramolecular steric hindrance.

DOI： 10.1039/c5ra20211f

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Helix-sense-selective photodegaradation of poly[4-dodecyloxy-3,5-bis(hydroxymethyl)phenylacetylene] (poly(DoDHPA)) in membrane state was achieved by selective photocyclic aromatization (SCAT) using single-handed circularly polarized light (CPL). This is the first example of kinetic optical resolution of helical polymers by using CPL.

DOI： 10.1246/cl.140469

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

5,4'-Bis(3,5-di-tert-buty1-4-acetoxypheny1)-2-ethynyl-2'-iodo-stilbene was synthesized and polymerized by the Sonogashira reaction to give the corresponding regioregular head-totail poly(1,2-phenyleneethynylene-1,2-phenylenevinylene). The polymer was converted to the corresponding hydroxy polymer after complete elimination of the protecting acetyl group by treatment with an alkaline solution. It was found that the folded helical conformation was preferred for the polymer containing the poly(1,2-phenylenevinylene) structure upon addition of methanol to the chloroform solution owing to the solvophobic interaction.

DOI： 10.1246/cl.140348

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Some 1,3-PPE-based polyradicals with pendent phenoxy radicals whose repeating unit consisted of four 1,3-phenyleneethynylene units were synthesized via polymerization between monomers and trimeric monomers in the presence of the Pd(PPh3)(4) complex catalysts. The ESR spectra of the polyradicals in dichloromethane showed unimodal broad signals. For the solid samples which were prepared from the dichloromethane solution by evaporating the solvent and by drying in vacuo, the signal intensity decreased with broadening of peak-to-peak line-width (Delta H-pp). However, the ESR spectra almost recover to the initial intensity and shapes due to redissolving in dichloromethane. In particular, the decrease of doubly integrating the ESR signal (I-ESR) was more remarkable for the polyradical bearing galvinoxyl and phenoxyl residues than others. This behavior suggests that strong antiferromagnetic interaction partially arose for the polyradical. (C) 2014 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2014.01.019

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

A facile synthesis of novel five 2D (planar) surface modifiers having a triphenylbenzene derivatives as a 2D structure has been achieved by the highly selective photocyclic aromatization reaction. Efficient enhancement of oxygen permselectivities through the three polymer membranes has been achieved by adding a small amount (< 5.0 wt%) of the 20 surface modifiers. Among the five 2D surface modifiers, a modifier compound having oligoethylene oxide groups showed the best performance for the enhancement. These improvements were thought to be caused mainly by improvement of the solution selectivity on the membrane surface where the 2D surface modifiers were accumulated. In some of the surface-modified blend membranes, their plots in the P-O2(-alpha) graph were over or close to the upper boundary line by Robeson in 1991. Since all the membranes containing the 2D surface modifiers showed better permselectivities than the corresponding substrate membranes, it is very promising for the future. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2013.11.046

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

An insoluble chiral membrane of one-handed helical multihydroxy poly(phenylacetylene) without the coexistence of any other chiral moieties has been synthesized by in situ complete removal of a one-handed helical poly(phenylacetylene) having multihydroxymethyl groups and chiral pinanyl groups in each polymeric unit in the membrane state. Although the enantiopermselectivity was decreased, the permeability increased four times by removing the chiral groups. In comparison with the corresponding poly(phenylacetylene) having no hydroxymethyl groups and chiral pinanyl groups, the loss of enantiopermselectivity was much lower. It is believed that the multihydroxy groups could maintain the main-chain chirality or enhanced interaction with permeant.

DOI： 10.1246/cl.130896

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Novel substituted acetylenes having a rigid planar substituent via a dynamic covalent imino group were synthesized and subsequently polymerized by using a chiral initiator system consisting Of an achiral rhodium complex and a chiral N,N-dimethylphenylethylamine to produce one-handed helical polymers having dynamic covalent imino groups. Furthermore, membranes could be produced from these chiral polymers that showed highly selective photocyclic aromatization (SCAT) and quantitative substitution of the side groups (RIM). Supramolecular polymer membranes having a high strength were obtained by SCAT. Chiral polymer membranes having many different kinds of side groups were easily obtained by RIM of the side groups.

DOI： 10.1295/koron.71.372

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

An amphiphilic 1,3,5-trisubstituted benzene as a new 2D surface modifier (T-EO) which has six hydroxy groups and three oligoethylene groups was successfully and easily synthesized by selective photocyclic aromatization in high conversion and selectivity for the first time. We prepared four kinds of blend membranes based on PVA or poly(trimethylsilylphenylacetylene) (poly(SPA)) containing the new amphiphilic cyclic trimer (T-EO) or the corresponding polymer (P-EO), that is, T-EO/PVA, P-EO/PVA, and T-EO/poly(SPA) membranes prepared by conventional solvent casting method (Method 1) and T-EO/poly(SPA) membranes prepared by a new solvent casting method (Method 11). T-EO/PVA membranes by Method I and T-EO/poly(SPA) membranes by Method II showed better performance in oxygen permeation than P-EO/PVA membranes by Method I and T-EO/poly(SPA) membranes by Method I, respectively. A PVA-based membrane containing 1.0 wt % T-EO showed the best performance, that is, the alpha became twice that of the original PVA membrane without any decrease in P-O2. The ideal improvement may be caused by effective surface modification by T-EO.

DOI： 10.1246/cl.130372

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

An achiral 3,5-bis(hydroxymethyl)phenylacetylene connected with a rigid and pi-conjugated substituent was polymerized using a rhodium (Rh) complex catalyst in the presence of chiral 1-phenylethylamines. The circular dichroism (CD) spectra of the polymers indicated that an excess of one-handed helical polyacetylene backbone was induced by helix-sense-selective polymerization under the asymmetric conditions despite the achiral monomer. The split-type-induced CD signals at 300 nm were attributed to the chromophore including the conjugated side group since the signal appeared at a longer wavelength than the poly[3,5-bis(hydroxymethyl)phenylacetylene] without conjugated substituent.

DOI： 10.1246/cl.130339

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

It has been achieved to obtain flexible self-supporting supramolecular polymeric membranes consisting of only 1,3,5-trisubstituted benzene derivatives prepared by highly selective photocyclic aromatization of the corresponding poly (substituted phenylacetylene)s having a columnar structure. The flexibilities of the self-supporting supramolecular polymeric membranes were enhanced by introducing hydroxyl groups or phenylene groups to the starting polymers (monomers). There were two reasons for the enhanced strength: 1) introduction of intercolumnar hydrogen bonds and 2) enhancement of the degree of intracolumnar stackings. This strength depended on the structure of the starting polymers which functioned as a template. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2013.05.063

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A novel phenylacetylene (1) having two hydroxyl groups and a chiral pinanyl group together with the other three related phenylacetylenes has been synthesized and (co)polymerized by using an achiral catalytic system. Among the four monomers, only 1 is suitable to the asymmetric-induced polymerization (AIP). Chiral amplification phenomenon is only observed in the copolymerization of 1 with an achiral phenylacetylene having two hydroxyl groups (3). The tight helical cis-cisoidal main chain formed by making intramolecular hydrogen bonds between the hydroxyl groups in the copoly(1/3) enhances the efficiency of chiral induction and as a result chiral amplification phenomenon is observed during the copolymerization.

DOI： 10.1002/marc.201300318

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Two poly(trimethylsilyldiphenylacetylene) membranes containing different contents of fluorine-containing groups were prepared by direct perfluorodecylation of poly(trimethylsilyldiphenylacetylene) (poly 1) in the membrane state using different ratios of (perfluorodecyl)phenyliodonium triflates to the phenyl groups in the polymer. The resulting perfluorodecylated poly(trimethylsilyldiphenylacetylene) (poly 2a and poly 2b) membranes were self-standing and tough. The two membranes showed better performance in oxygen permselectivity compared with all the membranes reported by many researchers. The performance (PO2 &gt
103 barrer and α = PO 2/PN2 = 2.9) of the poly 2a membrane having a lower content of the fluorine groups located on the upper boundary line reported by Robeson in 2008. The poly 2b membrane having a higher content of the fluorine groups was one of the polymers having the highest PO2 values (PO 2 &gt
104 barrer) in all the polymers reported.

DOI： 10.1016/j.polymer.2013.03.008

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Zwitterionic rhodium (Rh) complexes with tethered chiral amino and ether groups were synthesized by the reaction of [(C2H4)(2)RhCl](2) with the 2,5-norbornadiene tether, (CH2)(4)R [2: R = (R)-NHCH(CH3)Ph, 3: (R)-OCH(CH3)Ph], followed by exchange of Cl with BPh4. The resultant Rh complexes, 2 and 3, catalyzed the polymerization of 4-dodecyloxy-3,5-bis(hydroxymethyl)phenylacetylene (1) to afford polymers [poly(1)s] with number-average molecular weights of 16000 and 82000, respectively. The poly(1)s showed clear circular dichroism resulting from their polyacetylene backbones, which indicates the formation of predominantly one-handed helical structures.

DOI： 10.1246/cl.2013.278

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

By using a new achiral phenylacetylene having bulky substituents as a monomer, living-like helix-sense-selective polymerization (HSSP) has been achieved. This is the first example of the HSSP of substituted acetylenes where the degree of polymerization was controlled. The resulting one-handed helical living polymer initiated polymerization of a second monomer to successfully yield a block copolymer. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2013.02.009

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Helix-sense-selective polymerization (HSSP) of substituted acetylenes by using an isolated chiral Rh initiator with an amino acid ligand has been achieved. The sense of the helix of the main chain of the resulting polymer was controlled by the sign of the chirality of the ligand. The isolated initiator needed less of the chiral ligand and gave polymers having a higher value than the two component chiral initiator systems we reported previously. The resulting polymers had a higher Mw. © 2013 The Chemical Society of Japan.

DOI： 10.1246/cl.121295

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Four novel chiral phenylacetylenes having an L-amino alcohol residue and two hydroxymethyl groups were synthesized and polymerized by an achiral catalyst ((nbd)Rh+[?6-(C6H5)B-(C6H5)3]) or a chiral catalytic system ([Rh(nbd)Cl]2/(S)- or (R)-phenylethylamine ((S)- or (R)-PEA)). The two resulting polymers having an L-valinol or L-phenylalaninol residue showed Cotton effects at wavelengths around 430 nm. This observation indicated that they had an excess of one-handed helical backbones. Positive and negative Cotton effects were observed only for the polymers having an L-valinol residue produced by using (R)- and (S)-PEA as a cocatalyst, respectively, although the monomer had the same chirality. Even when the achiral catalyst was used, the two resulting polymers having an L-valinol or L-phenylalaninol residue showed Cotton effects despite the long distance between the chiral groups and the main chain. We have found the first example of a new type of chiral monomer, that is, a chiral phenylacetylene monomer having an L-amino alcohol residue and two hydroxy groups that was suitable for both modes of asymmetric polymerization, that is, the helix-sense-selective polymerization (HSSP) with the chiral catalytic system and the asymmetric-induced polymerization (AIP) with the achiral catalyst. The other two monomers having L-alaninol and L-tyrosinol were found to be unsuitable to neither HSSP nor AIP because of their polymers' low solubility. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

DOI： 10.1002/pola.26346

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

In this study, we investigated the helix-sense-selective polymerizations of newly synthesized achiral phenylacetylenes having two N-alkylamide groups, such as 3,5-bis(dodecylamide)phenylacetylene (DAPA), 3,5-bis(octylamide)phenylacetylene (OAPA), and 3,5-bis(butylamide)phenylacetylene (BAPA), by using a chiral rhodium catalyst system ([Rh(nbd)Cl](2)-(R)-(+)-1-phenylethylamine [(R)-PEA]). Poly(BAPA) was insoluble in any solvents. On the other hand, poly(DAPA) and poly(OAPA) were soluble in toluene, THF, and CHCl3, and the obtained polymers showed intense circular dichroism signals at the absorption region of the main chain in the UVvis region. This result suggested those polymers were present in helical conformations with an excess of one-handed screw sense. The chiral helix structures of the formed polymers were stable in toluene at room temperature for a long time because of intramolecular hydrogen bonds. This result is the second example about polyacetylenes with one-handed helical conformation stabilized by intramolecular hydrogen bonds.

DOI： 10.1021/mz300309c

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Copoly(hyperbranched macromonomer)s, i.e., poly(phenylacetylene)s having many branches were synthesized by one-pot simultaneous copolymerization of two kinds of dimethylsilyl-phenylacetylenes. Membranes from the copoly(hyperbranched macromonomer)s having several kinds of branches showed higher permselectivities for oxygen and carbon dioxide over nitrogen than those of the corresponding copoly(hyperbranched macromonomer)s without any branches. In particular, the copoly(hyperbranched macromonomer)s having long and rigid branches had both the advantages of poly(phenylacetylene)s and poly(dendron)s. In summary, copoly(hyperbranched macromonomer)s showing good performance as gas-separation membranes were synthesized very easily by the one-pot simultaneous polymerization method. To our knowledge, this is the first synthesis of such complex copolymers showing good performance as gas-separation membranes.

DOI： 10.1246/cl.2012.1462

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

A soluble and stable one-handed helical conjugated polymer without the coexistence of any other chiral moieties was successfully synthesized by asymmetric-induced polymerization of a chiral monomer having two hydroxyl groups followed by desubstitution of the chiral groups in a solid membrane state. The reason for the success was the polymer reaction was carried out in the membrane state. This is an alternative method to obtain such a unique chiral polymer which was obtained only by the helix-sense-selective polymerization (HSSP) we reported before. In addition the efficiency of the chiral induction was higher than that of the HSSP. It is interesting that the "Membrane state" acted like as if a protecting group. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2012.03.022

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Homochiral or enantioenriched helical polymers are essential for investigating the relationship between chirality of helical structures and their performance in the design of various optically active functional polymers. We have succeeded in obtaining the helical poly(phenylacetylene)s poly(1)-poly(6) possessing no chiral moieties, except for helicity; the enantioenriched helical sense of these polymers was induced by transformation in chiral solvents, followed by removal of the chiral solvents, even if the interaction between the chiral molecule and the polymer was weak such as solvent-solute interaction. In particular, the newly synthesized poly(6) retained the induced helical sense even in an achiral solvent. Polymer Journal (2012) 44, 327-333; doi:10.1038/pj.2011.144; published online 18 January 2012

DOI： 10.1038/pj.2011.144

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A new polymer prepared by polymerization of 3,5-bis(hydroxymethyl)phenylacetylene having a chiral menthyl group via a very long and rigid spacer by an achiral rhodium complex with triethylamine as an initiator showed strong CD absorptions assigned to the main chain in spite of the long distance (23 angstrom) between the chiral group and the polymerizing group in the monomer. This distance is the longest to the best of our knowledge. In addition, switching between the two chiralities of the resulting polymer was realized in the CD spectrum.

DOI： 10.1246/cl.2012.244

Web of Science

researchmap

Language：English   Publisher：AMER CHEMICAL SOC  

Web of Science

researchmap

Language：English   Publisher：AMER CHEMICAL SOC  

Web of Science

researchmap

Language：English   Publisher：AMER CHEMICAL SOC  

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

A soluble and stable one-handed helical poly(substituted phenylacetylene) without the coexistence of any other chiral moieties was successfully synthesized by asymmetric-induced polymerization of a chiral monomer followed by two-step polymer reactions in membrane state: (1) removing the chiral groups (desubstitution); and (2) introduction of achiral long alkyl groups at the same position as the desubstitution to enhance the solubility of the resulting one-handed helical polymer (resubstitution). The starting chiral monomer should have four characteristic substituents: (i) a chiral group bonded to an easily hydrolyzed spacer group; (ii) two hydroxyl groups; (iii) a long rigid hydrophobic spacer between the chiral group and the polymerizing group; (iv) a long achiral group near the chiral group. As spacer group a carbonate ester was selected. The two hydroxyl groups formed intramolecular hydrogen bonds stabilizing a one-handed helical structure in solution before and after the two-step polymer reactions in membrane state. The rigid long hydrophobic spacer, a phenylethynylphenyl group, enhanced the solubility of the starting polymer, and realized effective chiral induction from the chiral side groups to the main chain in the asymmetric-induced polymerization. The long alkyl group near the chiral group avoided shrinkage of the membrane and kept the reactivity of resubstitution in membrane state after removing the chiral groups. The g value (g = ([theta]/3,300)/epsilon) for the CD signal assigned to the main chain in the obtained final polymer was almost the same as that of the starting polymer in spite of the absence of any other chiral moieties. Moreover, since the one-handed helical structure was maintained by the intramolecular hydrogen bonds in a solution, direct observation of the one-handed helicity of the final homopolymer has been realized in CD for the solution for the first time.

DOI： 10.3390/molecules17010433

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：HINDAWI PUBLISHING CORPORATION  

様々な分野で応用が期待されるミクロおよびナノサイズのポリマー粒子の最近の進展について解説している。

DOI： 10.1155/2012/168412

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：HINDAWI PUBLISHING CORPORATION  

Monodendron monomers with alkoxy peripheral groups were synthesized, and the focal point of monodendrons, terminal acetylene, was polymerized with rhodium catalyst to yield corresponding polydendrons with a high molecular weight. The polydendrons were soluble in common organic solvents and readily formed membranes. Oxygen permselectivity was improved in the polydendrons with a space-persistent dendritic crowd. It was found that the well-defined dendritic and rod-like structure of the polydendrons was useful for permselective membrane.

DOI： 10.1155/2012/974204

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Pseudo helix-sense-selective polymerisation of a wide range of achiral substituted acetylenes having dynamic covalent bonds has been realised to yield static one-handed helical polymers without any other chiral moieties.

DOI： 10.1039/c2cc00030j

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The photochromic naphthalene-bridged imidazole dimer containing a naphthyl moiety that tethers two triarylimidazole units shows instantaneous coloration upon exposure to UV light and rapid fading in the dark. In this work, we demonstrate the formation of a stable chiral radical-pair that exhibits no photoracemization even by repeated photochromic cycles. The photogenerated radical-pair from the imidazole dimer exhibits the Cotton effect in the visible light region, indicating the retention of the enantiomeric conformation of the radical-pair. This result suggests that the chirality resulting from the binaphthyl moiety induces exciton coupling between the two radical chromophores by through-space interaction.

DOI： 10.1021/jz2012935

Web of Science

researchmap

Language：English   Publishing type：Part of collection (book)   Publisher：John Wiley and Sons  

DOI： 10.1002/9781118063965.ch15

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We synthesized two kinds of poly(1,3-phenyleneethynylenes), one has (+)-menthoxycarbonyl groups at all repeating units and the other has (+)-menthoxycarbonyl groups and n-dodecyloxy groups alternately. Self-supporting membranes could be obtained easily by solvent casting. Enantioselective permeations of the polymers were investigated by pervaporation of 2-butanol. Enantioselective permeabilities of the membrane consisting of one-handed helical foldamer and unfoldamer were clarified.

DOI： 10.1246/cl.2011.384

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society for Engineering Education  

An educational practice entitled "Breaking Away from Shallow Learning Habits" of the Faculty of Engineering, Niigata University is adopted as "Good Practice (GP) of Education" by The Ministry of Education, Culture, Sports, Science and Technology. This practice consists of a new introductory educational program for freshmen entitled "Introduction to Engineering Literacy" , as well as improvement of other lectures/experimentations/exercises for design education. "Introduction to Engineering Literacy" of The Department of Chemistry and Chemical Engineering, is programmed to let the students make "failure" (discrepancy from the knowledge obtained from the textbooks) in experiments, let them propose improvement, and let them conduct the same experiment again after the improvement, so that the freshmen can experience a PDCA (Plan-Do-Check-Action) cycle.

DOI： 10.4307/jsee.59.2_74

CiNii Article

CiNii Books

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

To develop new phenylacetylene monomers more suitable for helix-sense selective polymerization (HSSP) we reported previously and to improve the efficiency of the HSSP and membrane performance of the resulting polymers, novel phenylacetylenes having a flexible oligosiloxanyl group (SnBDHPA) together with the other related three series of monomers were synthesized and polymerized by using a chiral catalytic system and enantioselectivity in permeation of the membranes from the resulting chiral polymers were examined SnBDHPA was the most suitable for the HSSP and the CD absorptions (G values) of poly (SnBDHPA) were stronger and more stable than those of the corresponding polymers having rigid alkyl groups The polymers could be fabricated to flexible self supporting membranes by using solvent casting method In addition, enantioselectivity in permeation of one of poly(SnBDHPA) membranes was much higher than that of a poly(phenylacetylene) membrane having alkyl groups This was because the polymers having oligosiloxane groups had high regularity of structures, i e, chemical structures of the macromolecules such as one handedness and high order structures such as columnar contents in the membranes, and the membranes were flexible and had almost no defects These good properties as optical resolution membrane materials were caused by flexibility, hydrophobicity, and bulkiness of the oligosiloxane chains S3BDHPA having a trisiloxanyl group was found to be the best monomer for the HSSP and for obtaining good optical resolution membrane materials

DOI： 10.1021/ma101999k

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Three novel chiral phenylacetylenes having in octyloxyethanolamine residue derived from a L-aminoalcohol and two hydroxymethyl groups were synthesized and polymerized by two achiral catalysts ((nbd)Rh(+)[eta(6)-(C(6)H(5))B(-)(C(6)H(5))(3)] and [Rh(nbd)Cl](2)/triethylamine (TEA)) and a chiral catalytic system ([Rh(nbc)Cl](2)/(S)- or (R)-phenylethylamine ((S)- or (R())-PEA)). All of the resulting polymers showed Cotton effects at wavelengths around 430 nm. This observation indicated that they had an excess of one-handed helical backbones. Positive and negative Cotton effects were observed for the polymers having an L-valinol residue produced by using (S)- and (R)-PEA as it cocatalyst, respectively, although the monomers had the same chirality. The two polymers having in L-aliminol or L-phenylalaninol residues obtained by using (S)- and (R)-PEA as a cocatalyst showed CD absorptions with identical signs. Therefore, we found that the chiral monomer having an L-valinol residue was suitable for both modes of asymmetric polymerization, that is, helix-sense-selective polymerization (HSSP) with the chiral catalytic system and asymmetric-induced polymerization (AIP) with the achiral catalysts. However, the other two monomers having an L-alaninol or L-phenylalaninol residue were not suitable for HSSP because the helix sense could not be controlled by the chirality of PEA. To explain the unexpected behaviors in the asymmetric polymerizations of the two chiral monomers having a chiral bidentate ligand, a novel third mechanism of asymmetric polymerization, that is, self-helix-sense-selective polymerization (SHSSP), is proposed in this Article. This Article discusses the contribution of the three mechanisms (AIP, HSSP, and SHSSP) in asymmetric polymerizations of the three monomers.

DOI： 10.1021/ma101424x

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

To develop a new phenylacetylene monomer suitable for helix-sense-selective polymerization (HSSP) we reported previously and to improve the efficiency of the HSSP and membrane performance of the resulting polymer, a novel phenylacetylene having a trisiloxanyl group (S3BDHPA) was synthesized and polymerized by using a chiral catalytic system and enantioselectivity in permeation of its membrane was examined. S3BDHPA was suitable for the HSSP and the CD absorption of poly(S3BDHPA) was stronger and more stable than that of the corresponding polymer having no siloxanyl groups. In addition, enantioselectivity in permeation of poly(S3BDHPA) was much higher than that of a polymer membrane having no siloxanyl groups. They are thought to be caused by the flexibility and hydrophobicity of the trisiloxane groups. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2010.04.030

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We synthesized optically active polyradicals possessing an excess of one-handed helical backbone by helix-sense-selective polymerization (HSSP) of achiral monomers which was promoted by rhodium complex catalyst in the presence of (R)- or (S)-1-phenylethylamine. The monomer, which had two hydroxy groups and a hydrogalvinoxyl unit, gave the corresponding polymer with an optically active helical conformation stabilized by intramolecular hydrogen bonding. The chemical oxidation of the polymer yielded the corresponding optically active helical polyradical with high spin concentration. The static magnetic susceptibility of the chiral polyradical was measured using a SQUID magnetometer. We have found that the stronger antiferromagnetic interaction was observed for the polyradical synthesized by HSSP in comparison with the polyradical via polymerization in the presence of racemic phenylethylamine. (C) 2008 Elsevier Ltd. All rights reserved

DOI： 10.1016/j.poly.2008.10.067

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

In this study, we synthesized four chiral helical poly(phenyleneethynylenes) having optically active menthoxycarbonyl groups and desubstituted the chiral groups in membrane state. Polycondensations of (+)-menthyl 3,5-diethynylbenzoate with (+)-menthyl 3,5-diiodobenzoate, 1,2-diiodobenzenen, 1,3-diiodobenzene, and 1,4-diiodobenzene using PdCl(2)(PPh(3))(2)-PPh(3)-Cul were afforded helical polymers in good yields (named as PMtMt, o-PMtH, m-PMtH, and p-PMtH, respectively). Among them, PMtMt in a mixture of chloroform/benzene showed the largest Cotton effect in absorption region and gave self-supporting membrane by solvent-casting method. PMtMt membrane also showed a Cotton signal similar to that observed in solution. Desubstitution of PMtMt proceeded quantitatively by immersing the membrane into alkaline solution at room temperature for 3 days. The desubstituted PMtMt membrane showed circular dichroism (CD) signals similar shape to that of the original membrane in the UV region in despite of the polymer having no chiral moieties except for helical conformation. This is the first example of synthesis of chiral helical poly(phenyleneethynylenes) without the coexistence of any other chiral moieties. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.synthmet.2009.01.038

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

We synthesized an optically active poly(binaphthyl-6,6'-diylethynylene-1,3-phenyleneethynylene) with pendant galvinoxyl residues. The hydrogalvinoxyl precursor polymer was given by polymerization of (1,3-diiodophenyl)hydrogalvinoxyl and 6,6'-diethynyl-2,2'-dihexyloxybinaphthyl using Pd(PPh(3))(4) catalyst (M(w) = 4.6 x 10(4), M(w)/M(n) = 30). The polymer yielded the corresponding polyradical with high spin concentration by treatment of the polymer solution with PbO(2). In the CD spectra of the polymer and polyradical taken in various solutions, clear Cotton effects were observed in the absorption region of the binaphthyl chromophore, while no Cotton effect was observed in that of the galvinoxyl chromophore. On the other hand, in the MCD, Faraday effects were observed in the absorption region of the backbone and galvinoxyl chromophore. The static magnetic susceptibility of the chiral polyradical was measured using a SQUID magnetometer, and showed weak antiferromagnetic interaction. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.synthmet.2009.01.042

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

4-Alkyloxy-3,5-bis(hydroxymethyl)phenylacetylenes with eight types of alkyl groups were synthesized and polymerized with a chiral catalytic system. We found that the length of the alkyl groups played a very important role in achieving helix-sense-selective polymerization. Five helix-sense-selective polymerizations were achieved resulting in polymers with alkyl groups whose chain length was longer than six. We think that the longer-chain alkyl groups prevented the polymers from becoming insoluble by forming intermolecular hydrogen bonds between the hydroxyl groups, and stabilized their one-handed helical structure by promoting the formation of intramolecular hydrogen bonds.

DOI： 10.1002/macp.200800594

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Phenyleneethynylene macrocycle-substituted acetylenes were synthesized by repetition of the Sonogashira coupling reaction, and the elimination reaction of the terminal acetylene protecting group. The monomers were polymerized with a rhodium catalyst, [Rh(nbd)Cl](2), at the terminal acetylene unit, and the polymerization mixtures were purified by precipitating into methanol to yield the corresponding poly(phenylacetylene) derivatives as yellow-red powders, which had a high degree of polymerization ((DP) over bar approximate to 500) in spite of their steric bulkiness. The trimethylsilyl and pentamethyldisiloxanyl groups of polymers improved their solubility, and the polymers were soluble in common organic solvents, such as toluene, chloroform and tetrahydrofuran.

DOI： 10.1002/macp.200800429

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

L-バリノール残基と二つのヒドロキシメチル基を有する光学活性なフェニルアセチレン誘導体を合成し、キラル触媒系でのらせん選択重合と光学活性基に誘導された不斉誘起重合の両方が可能であることを明らかにした。

DOI： 10.1021/ma802313z

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Achiral phenylacetylene monomers were polymerized using a rhodium (Rh) complex catalyst in the presence of (S)1-phenylethylamine. Addition of copper(I) iodide (CuI) into the catalytic system improved the polymer yield. The monomer, which had two hydroxy groups and a hydrogalvinoxyl unit, gave the corresponding polymer with an optically active helical conformation stabilized by intramolecular hydrogen bonding. The chemical oxidation of the polymer yielded the corresponding optically active helical polyradical with high spin concentration.

DOI： 10.1246/cl.2008.390

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Helix-sense-selective polymerization of {4-[(3,5-di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxo-cyclohexa-2,5-dienylidene)methyl]phenyl}acetylene (abbreviated as (4-ethynylphenyl)hydrogalvinoxyl) was promoted by [Rh(cod)Cl](2) and [Rh(nbd)Cl](2) catalyst in the presence of (R)-(+)-1-phenylethylamine or (S)-(-)-1-phenylethylamine (PEA). The [Rh(cod)C](2) Catalyst system gave red polymers whose CD spectra showed the stronger Cotton effect though the yield (2-3%) and molecular weight (M-n = (1.1 - 1.4) x 10(4)) were lower than those of polymers obtained by [Rh(nbd)Cl](2). Moreover, we investigated the effect of bulkiness of the catalyst, cocatalyst, and monomer on helix-sense-selective polymerization of (4-ethynylphenyl)hydrogalvinoxyl in the presence of (R)-PEA. The CD patterns of polymers obtained by [Rh(nbd)Cl](2) and [Rh(cod)Cl](2) were nearly mirror image of each other, except for the magnitudes of the signals in spite of the same chiral condition, i.e., in the presence of (R)-PEA. That is, [Rh(nbd)Cl](2) and [Rh(cod)Cl](2) catalysts generated P-helix and M-helix, respectively. This is a novel result, since the control of helix sense is usually achieved by enantiomeric moieties of catalysts or initiators for the helix-sense-selective polymerization.

DOI： 10.1021/ma0713963

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A nanocomposite film of tungsten trioxide (WO3) and [Ru(bpy)(3)](2+) (bpy = 2,2'-bipyridine) (denoted as Ru-WO3) was prepared from an aqueous colloidal triad solution containing peroxotungstic acid, [Ru(bpy)(3)](2+), and poly(sodium 4-styrenesulfonate) by an electrodeposition technique. The electrochemical features of the Ru-WO3 film were investigated using cyclic voltammetry (CV) and potential-step chronoamperospectrometry (PSCAS) techniques, compared with those in a [Ru(bpy)(3)](2+)/Nafion (Ru-Nf) film. PSCAS data spectrophotometrically showed that Ru-II is completely oxidized for 0.3 s in the Ru-WO3 film, in contrast to the corresponding reaction completed for 30 s in the Ru-Nf film. The apparent diffusion coefficient (D-app = (0.1-1.1) x 10(-7) cm(2) s(-1)) for charge transport (CT) by a Ru-II/Ru-III redox in the Ru-WO3 film was higher than that (2.4 x 10(-10) cm(2) s(-1)) in the Ru-Nf film by 2 or 3 orders of magnitude. Activation energy (E-a) for CT (14.1 kJ mol(-1)) for the Ru-WO3 film was 3.5 times lower than that (E-a = 49.8 kJ mol(-1)) for the Ru-Nf film. The lower E-a could be responsible for the faster CT in the Ru-WO3 film than the Ru-Nf film. D-app in the Ru-WO3 film increased linearly with an increase of the final applied potential (E-f) for PSCAS from 1.2 to 1.5 V vs SCE and saturated above E-f = 1.5 V. The mechanism for CT in the Ru-WO3 film is proposed, in which electrons are injected from [Ru(bpy)(3)](2+) into the conduction band (CB) of WO3 and go through there to a collector electrode.

DOI： 10.1021/jp073020x

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A hybrid film of WO3/tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)(3])(2+)) /poly(sodium 4-styrenesulfonote) (PSS) (denoted as a WRP hybrid film) was prepared as a base layer on an indium tin oxide electrode substrate by cathodic electrodeposition from a colloidal ternary solution containing peroxotungstic acid, [Ru(bpy)(3)](2+), and PSS. Prussian blue, Fe-4(III)[Fe-II(CN)(6)](3) (Fe-II-Fe-III) was cathodically electrodeposited on the WRP hybrid film from a Berlin brown (Fe-II-Fe-III) colloidal solution to give a WRP/Fe-II-Fe-III biloyer film. Spectrocyclic voltammetry measurement of the WRP/ Fe-II-Fe-III bilayer film reveals that Prussian white (Fe-II-Fe-III) is oxidized to Fe-II-Fe-III by electrogenerated Ru-III, and Fe-II-Fe-III is re-reduced to Fe-II-Fe-III by electrogenerated HxWO3. Visible-light irradiation of the WRP hybrid film generates a small photocurrent (approximate to 8 nA cm(-2)) at 0.4 V of an applied potential, whereas irradiation of the WRP/Fe-II-Fe-III bilayer film (Fe-II-Fe-III is electrochemically reduced to the Fe-II-Fe-III state) significantly generates a steady photoonodic current of 2.0-1.1 mu A cm(-2) under the some conditions, thus demonstrating that the photoanodic current is produced by the layered Fe-II-Fe-III film. The photoaction spectrum of the bilayer film reveals that the photoanodic current is based on the photoexcitation of [Ru(bpy)(3)](2+). The photogeneration of Fe-II-Fe-III from Fe-II-Fe-III is shown by the absorption spectral change of the bilayer film on irradiation. These results corroborate the notion that Fe-II-Fe-III is oxidized by photogenerated Ru-III to generate Fe-II-Fe-III. However, the rote of photogenerotion of Fe-II-Fe-III is slow, which could be ascribed to the fast back electron transfer (ET) from WO3 to Ru-III, comparable with the forward ET from Fe-II-Fe-III to Ru-III. The fast back ET could be a crucial problem for the [Ru(bpy)(3)](2+)-sensitized reaction in the hybrid film.

DOI： 10.1002/cphc.200700192

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We synthesized an optically active helical poly(1,3-phenyleneethynylene) with pendant galvinoxyl residues and dimethyl(10-(1S)pinanyl)silyl groups. The hydrogalvinoxyl precursor polymer was given by polymerization of (1,3-diiodophenyl)hydrogalvinoxyl and 1,3-diethynyl-5-[dimethyl(10-(1S)-pinanyl)silyl]benzene using Pd(PPh3)(4) catalyst (M-w = 1.7 x 10(5), M-w/M-n = 3.7). In the CD spectrum taken in ethyl acetate solution, clear Cotton effects were observed in the absorption region of the backbone and hydrogalvinoxyl chromophore, indicating an excess of one-handed helical foldamer conformation. The polymer yielded the corresponding polyradical with high spin concentration by treatment of the polymer solution with PbO2. The Cotton effects appeared in CD spectra of the polymer and polyradical by addition of methanol to the chloroform solution, although the Cotton effects were hardly observed in chloroform. On the other hand, in the MCD spectra of the polymer and polyradical taken in chloroform solution, Faraday effects were observed in the absorption region of the backbone and galvinoxyl chromophore. The static magnetic susceptibility of the chiral polyradical was measured using a SQUID magnetometer, and showed the antiferromagnetic interaction. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.poly.2006.09.104

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A chiral helical poly(phenylacetylene) bearing N-(2-hydoroxyethyl)aminomethyl groups as ligand sites was synthesized by helix-sense-selective polymerization. In the obtained polymeric membrane, the ligands could complex with Cu2+. In permeation of aqueous solution of racemic phenylalanine, enantioselectivity in permeation through the Cu2+ complexing membrane was about 3 times higher than that of the original membrane.

DOI： 10.1246/cl.2007.220

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Monodendrons consisting of m-linked phenyleneethynylene repeating unit with trimethylsilyl-, pentamethyldisiloxanyl- and nonamethyltetrasiloxanyl-peripheral groups were synthesized using the convergent approach. The focal point of monodendrons, terminal acetylene, was polymerized with rhodium catalyst to yield corresponding polydendrons with a high molecular weight. The polydendrons were solubile in common organic solvents, and readily formed membranes. Oxygen permselectivity was improved in the polydendrons with a space-persistent dendritic crowd. It was found that the well-defined dendritic and rod-like structure of the polydendrons was useful for pemselective membrane. Oxygen permselectivity was increased in polydendrons with a trimethylsilyl group compared to the corresponding zero generation poly(phenylacetylene) derivatives. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.memsci.2005.11.023

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

We have succeeded in the helix-sense-selective polymerization of achiral phenylacetylene monomers bearing galvinoxyl moiety using the catalyst [Rh(nbd)Cl] 2 or [Rh(cod)Cl], in the presence of chiral 1-phenylethylamine. Oxidizing the hydroxyl groups of the optically active helical polymers gave the corresponding chiral polyradicals showing Cotton effects in the CD spectra.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

A Phthalocyanine Zinc (II) (ZnPc) / Nafion (Nf) hybrid film was prepared by casting the mixture solution of ZnPc and Nf, and a reversible association-dissociation of ZnPc in the Nf film was studied using a UV-visible absorption spectroscopic technique. It was found that a zinc phthalocyanine dimer in the film is dissociated reversibly to form the monomers when the Nf / ZnPc film is dipped in a 0.1 M LiCl electrolyte solution (pH = 7). The dissociation rate increased with the concentration of cations such as Li +, Na+, and K+. We present thermodynamic and kinetic discussions about the reversible association-dissociation of ZnPc in the film.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We synthesized poly(1,3-phenyleneethynylene) derivatives bearing galvinoxyl groups. The chiral polymer was synthesized by polycondensation of (1,3-diiodophenyl)hydlogalvinoxyl and chiral diethynylbenzene monomers using Pd-catalyst (yield = 87%, M n, = 4.7×10 4, M w / M n= 4.1). The CD spectrum of the poly(1,3- phenyleneethynylene) bearing hydrogalvinoxyl and chiral pinanylsilyl groups showed the Cotton effect in chloroform/methanol (1/1 v/v) at -10 °C. The chiral polyradical was obtained by chemical oxidation of the corresponding hydroxyl polymer, which was confirmed by the Cotton effect of galvinoxyl radical chromophore at 470nm. The magnetic properties of polyladicals were discussed using ESR, CD and a SQUID magnetometer.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Chiral helical poly(phenylacetylene) bearing ligand site was synthesized by helix-sense-selective copolymerization of DoDHPA and HAMPA. Solubility and CD activity of the obtained copolymer decreased with the increase of HAMPA content. The copolymer membrane exhibited complexation ability with Cu2-. In permeation tests of aqueous solution of racemate of DL-phenylalanine, the Cu2- coordinated copolymer membrane showed enantioselective permeability higher than original copolymer membrane. This suggests that the complexation may improve chiral recognition ability of the polymer.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We synthesized chiral/achiral phenylacetylenes with or without two hydroxyl groups (1-4). CD active polymers were obtained by polymerization of optically active pinanylsilyl group and two hydroxyl groups containing monomer (1) using achiral Rh catalyst and dodecyl group and two hydroxyl groups containing monomer (3) using chiral Rh catalyst. On the other hand, polymerizations of monomers without two hydroxyl groups having optically active pinanylsilyl group (2) or dodecyl group (4) using achiral Rh catalyst gave CD inactive polymers. The obtained polymers showed the lower angle side peaks around 2θ = 4.0-5.0° (d = 17-22Å) attributed to the (100) reflection in the polymer. The broad peak at 2θ = 20° (d = 4.4Å) should be assigned to the amorphous halo. On the basis of these results it was concluded that all the polymers had a pseudohexagonal (columnar) packing structures in the solid state. In addition, aging effect of polymer solution on molecular weight and molar ellipticity were investigated. In result, CD active polymers (poly(1) and poly(3)) showed higher stability than CD inactive polymers (poly(2) and poly(4)).

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We have already succeeded in synthesizing a poly(9,10-anthryleneethynylene) with pendant phenoxyl radicals at the 2- and 7-positions which has high durability to spin defects and a large average S value (S = 5/2) corresponding to the ferromagnetic spin coupling network spreading throughout the ≥-conjugated chain. The coplanarity of ≥-conjugated pendant polyradicals throughout the backbone chain and pendant side chain is significantly effective in the magnitude of the spin polarization and the spin-exchange coupling constant. In this study, we synthesized the corresponding dimer models to discuss the electronic and magnetic properties of the polyradical related to the conformation using UV/vis and fluorescence spectra, ESR and CV in various solvents. The UV/vis spectrum of the dimer showed a broad absorption peak at 488 nm in chloroform. On the other hand, the absorption peak showed narrowing, and a new peak appeared at 520 nm in heptane, dodecane, methanol and cyclohexane. The peaks at 488 nm and 520 nm were attributed to the oligo(anthryleneethynylene) chromophore with twisted and coplanar conformations, respectively. The temperature dependence of UV/vis spectra indicated the grand state of twisted conformation in chloroformand that of coplanar conformation in heptane.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Polyradical possessing a one-handed helical structure would promise interesting magnetic and chiroptical properties. In this study, we have newly synthesized a poly(1,3-phenyleneethynylene)-based polyradical bearing galvinoxyl and dimethyl(10-(1S)-pinanyl)silyl group. The hydrogalvinoxyl precursor polymer was given by polymerization of (1,3-diiodophenyl)hydrogalvinoxyl and 1,3-diethynyl-5-[dimethyl(10-(1S)-pinanyl)silyl]benzene using Pd(PPh 3)4 catalyst (yield = 87%, Mn = 4.7 × 104, Mw/Mn = 4.1). The polymer yielded the corresponding polyradical with high spin concentration by treatment of the polymer solution with PbO2. In the CD spectrum taken in ethyl acetate solution, clear Cotton effects were observed in the absorption region of the backbone and hydrogalvinoxyl chromophore, indicating an excess of one-handed helical foldamer conformation, while no Cotton effects were observed in chloroform, THF and benzene solution. However, the Cotton effects appeared in CD spectra of the polymer and polyradical by addition of methanol to the chloroform solution. On the other hand, in the MCD spectra of the polymer and polyradical taken in chloroform solution, Faraday effects were observed in the absorption region of the backbone and galvinoxyl chromophore.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

The degradability of chiral helical poly(4-dodecyloxy-3,5- bis(hydroxymethyl)phenylacetylene) (poly(DoDHPA)) and poly((-)-4- (dimethylpinanylsilyl)phenylacetylene (poly(PSPA) was investigated. In THF solution, the chiral helical structure of poly(DoDHPA) was more stable than that of poly(PSPA). On the other hand, poly(DoDHPA) membrane degraded faster than poly(PSPA) membrane in water or methanol. The degradability of poly(DoDHPA) membrane in poor solution was unexpected for us. In addition, the membrane immersed in water included the degraded compound more than that immersed in methanol. From 1H and 13C NMR measurement, it was found the degraded compound had a ring structure, the fact suggests the degradation on the main chain occurred together with cyclization.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Synthesis of chiral poly(phenyleneethynylene) membranes containing chiral menthyl or pinanyl silyl groups were examined. Their chiral helical main-chain structures were observed by CD measurement and removal of the chiral group from the chiral helical membranes were attempted. The polymer had a fairly high molecular weight(Mw = 4×l04) and gave a self-supporting membrane easily by solution casting method. In the CD spectrum of the polymer in CHCl3 / benzene, the Cotton signal increased as the content of benzene increased.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Poly(4-dodecyloxy3,5-bis(hydroxymethyl)phenylacetylene) had one-handed helicity in the main chain. To immobilize the chiral helical structure, transformation of the hydrogen bonds between side groups, which stabilizes the helicity to covalent bonds, was carried out by condensation with dichlorodimethylsilane. In IR spectra of the resulting polymers, new peaks attributed to Si-O-C bond appeared and a band attributed to O-H band became weaker. The molar ellipticity of the fixed polymers hardly decreased when the polarity of solvent increased.

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Phthalocyanine zinc(II) (ZnPc) was found to be adsorbed well into a Nafion (Nf) film. The kinetic analysis suggested that the adsorption of ZnPc into the Nf film is controlled by its diffusion in the Nf film with a diffusion coefficient of D = 1.9 x 10(-6) cm(2) s(-1) that is higher than those (10(-9)-10(-12) cm(2) s(-1)) of cationic redox molecules in the Nf film by 3-6 orders of magnitude. The adsorption isothermal was analyzed by a Brunauer-Emmett-Teller (BET) equation suggesting multilayer adsorption of ZnPc into the film. The BET analysis provided the amount of ZnPc for monolayer adsorption (w(m) = 1.50 x 10(-7) mol cm(-2)), from which the effective area for the ZnPc adsorption was estimated to be larger by a factor of 1.7 x 103 than the Nf film area (1.0 cm(2)). The absorption spectra of a Nf film adsorbing ZnPc ((Nf/ZnPc)(ads) film) exhibited two broad absorption bands at 385 and 680-750 nm without any structural features, which is significantly different from the absorption spectra of either ZnPc solution in DMF or a (Nf/ZnPc)(mix) film prepared from a DMF solution containing Nf and ZnPc by solvent evaporation. This is ascribed to the formation of a ZnPc aggregate in the (Nf/ZnPC)(ads) film. Photoluminescence data for the (Nf/ZnPc)(mix) film suggested the presence of a ZnPc monomer and dimer at equilibrium in the film with a concentration of 0.1 M and that energy transfer occurs from the monomer to the dimer in excitation of the monomer (at A x = 609 nm) to yield emission from the dimer. By contrast, photoluminescence data for the (Nf/ZnPc)(ads) film suggested that the excited ZnPc is self-quenched significantly by the formation of the ZnPc aggregate in the film. The lesser electroactivity of ZnPc in the (Nf/ZnPc)(ads) film compared with that in the (Nf/ZnPc)(mix) film could be ascribable to more difficult diffusion of ZnPc in the former film due to the formation of the ZnPc aggregate. The adsorption of ZnPc into the Nf film was significantly regulated by simple pretreatments of the Nf film such as immersion in solvents and storage under solvent vapors. The regulation was explained by controlled physical and chemical properties of a channel for mass and ion transport that is formed by sulfonate groups, countercations, and solvent molecules in the Nf film.

DOI： 10.1021/jp052218j

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

{4-[(3,5-Di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dienylidene)methyl] phenyl}acetylene (abbreviated as (4-ethynylphenyl)hydrogalvinoxyl) was polymerized using [Rh(norbornadiene)Cl](2) catalyst in the presence of (R)-1-phenylethylamine or (S)-1-phenylethylamine to give red polymers. The circular dichroism (CD) spectra of polymers indicated that an excess of one-handed helical polyacetylene backbone was induced by helix-sense-selective polymerization under the asymmetric condition despite the achiral monomer. Results show that the CD signal intensity depends on temperature and decreases reversibly with increasing temperature, although the energy difference between the right-handed and left-handed conformations of each other is almost zero. The sign of the CD signal in the absorption region (420 nm) of the hydrogalvinoxyl chromophore, which was calculated from the polymer geometry, suggests that the excess of right-handed helix was induced by polymerization in the presence of (R)-1-phenylethylamine.

DOI： 10.1021/ma050864a

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We synthesized monodisperse oligo(9,10-anthryleneethynylene)s with pendant phenol residues at the 2- and 7-positions. The absorption maxima of oligomers shifted to longer wavelength with the degree of polymerization, suggesting a developed pi-conjugation correlated with the chain length. The static magnetic susceptibility of the dimeric radical was measured using a SQUID magnetometer, and the 2J (J: spin coupling constant through the dianthrylacetylene unit) value of the dimeric radical was 34 cm(-1), which agreed with the 2J value of the corresponding 2-substituted dimeric radical (31 cm(-1)). These large 2J values of the dimeric radicals can be explained from less steric hindrance between the side chain radicals and the backbone. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polt.2005.03.127

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Two new chiral helical poly(hydroxyl-containing phenylacetylene) membranes without the coexistence of any other chiral moieties were prepared in the following manner: (1) synthesis and homo-or copolymerization of two new chiral pinanylsiloxy-containing phenylacetylenes, (2) preparation of self-supporting membranes from the (co)poly(chiral pinanylsiloxy-containing phenylacetylene)s by a solvent-casting technique, and (3) depinanylsilylation of the preformed polymer membranes in situ. Complete depinanylsilylation was successfully achieved by treating with trifluoroacetic acid. The resulting membranes exhibited circular dichroism despite the absence of the chiral substituents, a fact indicating that the main chains of the polymers retained their chiral helicity. This is the first method to synthesizing such chiral poly(phenylacetylene) membranes. Since the membranes maintained their self-supporting properties, we were able to use them as enantioselective separation membranes in the permeation of an aqueous solution of a racemate. As a result, the importance of the contribution of the chiral main chain on enantioselective permeation was directly confirmed for the first time. In addition, since some of the depinanylsilylated membranes were insoluble in organic solvents, we could use them as an separation membrane for a toluene solution of a racemate.

DOI： 10.1021/ma0500898z

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

An achiral and bulky phenylacetylene monomer, (4-ethynyl-phenyl)hydrogalvinoxyl), was polymerized using [Rh(nbd)Cl](2) (nbd = 2,5-norbornadiene) catalyst in chiral phenylethylamine. The circular dichroism (CD) spectra of the obtained polymers indicated that an excess of one-handed helical polyacetylene backbone was induced by helix-sense-selective polymerization despite the achiral monomer.

DOI： 10.1246/cl.2005.854

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

We synthesized two kinds of chiral polystyrene-based monoliths, which are macroporous gel with continuous open-celled monolith structure. Thus, two chiral styrene monomers, (-)-p-[dimethyl(10-pinanyl)silyl] styrene ((-)-PSSt) and (-)-p-(menthoxycarbonyl)styrene ((-)-MtSt]), were prepared and subjected to water-in-oil emulsion polymerization in the presence of divinylbenzene and AIBN. The macroporous structure of the obtained monoliths was directly confirmed by SEM observation. The obtained monoliths showed an optical resolution ability. That is, in the enantioselective adsorption using trans-stilbene oxide, poly[(-)-PSSt] monolith and poly[(-)-MtSt] monoliths preferentially adsorbed (SS)-isomer [poly[(-)-PSStl monolith: α((S,S)) = 1.49 (0.25 wt % acetone solution); poly[(-)-MtSt] monolith: α((S,S)) = 1.39 (0.25 wt % toluene solution)]. Depinanylsilylation of the poly[(-)-PSStl monolith and removal of menthyl groups from the poly[(-)-MtSt] monolith were achieved by acid-catalyzed. scission of the Si-C bond and base-catalyzed hydrolysis, respectively. In addition, de-poly[(-)-PSSt] and de-poly[(-)-MtSt] showed enantioselectivity ((SS)-isomer preferentially absorbed) in adsorption using trans-stilbene oxide in spite of the absence of chiral substituents in the monoliths. © 2005 Wiley Periodicals, Inc.

DOI： 10.1002/pola.20645

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Chemistry of macromolecular architecture is one of the fastest growing branches of polymer chemistry. The present review describes macromolecular architectures for permselective membranes relating their structures and permselectivity, and is focused on dendrimers for gas permselective membranes and one-handed helical polymer membranes for enantioselectively permeable membranes (optical resolution). The first part of this review described the three kinds of permselective membranes prepared from pure polydendrons or dendronized polymers having self-membrane-forming ability by us, and from another polymer and dendrimers or hyperbranched polymers as a crosslinker, and from another supporting membrane and dendrimers as a modifier. The membranes from polydendrons showed better oxygen permselectivities than those of conventional polymer membranes. In the second part, three kinds of enantioselectively permeable membranes reported by many researchers, i.e., chiral carriers-containing composite membranes, membranes based on chiral HPLC stationary phase polymers, and chiral molecular imprinting membranes, are reviewed briefly. In particular, the detail of our macromolecular designs of one-handed helical poly(substituted acetylene)s as materials for enantioselectively permeable membranes is discussed as the fourth category. When the content of the chiral groups was higher, the permselectivity was enhanced. The one-handed helical backbones were found to be effective for enantioselective permeation. It was also shown that the disadvantage of this method, i.e., low permeation rate was improved by using thinner membranes. In addition, enantioselectively permeable membranes are classified from the view point of their permeation mechanisms.

DOI： 10.1295/polymj.37.717

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

A new porous ion exchange resin having an open-celled monolith structure was prepared and its ion exchange properties were examined. The new ion exchange resin was found to have the following advantages over the conventional ion exchange resins having bead structures. First, the new ion exchange resin has a high adsorption ability for the ions having low selectivity coefficients, and the ion exchange band length is smaller than that of the conventional resins. Second, in an electric field, the rejection time of the ions adsorbed to the new ion exchange resin was about one twentieth of that of the ions containing the conventional resins. These specific properties of the new ion exchange resin are attributable to the quantitative introduction of ion exchange groups into the resin having a uniform open-celled monolith structure.

DOI： 10.1295/koron.62.7

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Achiral phenylacetylenes(RHPA) having two hydroxymethyl groups and an alkyloxy group of various chain length and shaps (R = n-octyl(Oc), n-decyl(De), n-undecyl(U), n-dodecyl(D), 2-ethylhexyl(EH), 4-methylpentyl(MP)) in 4-position were synthesized. These monomer were polymerized using a chiral catalytic system. Polymers of OcHPA, DeHPA, UHPA, and DHPA obtained Cotton effects at wavelengths around 430nm and 307nm in CD (Fig. 1) indicating the main-chains have a chiral helical conformation. It was found that these monomers were suitable for the helix-sense-selective polymerization. The molar ellipticity values([θ]) of Poly(DHPA) and poly(OcHPA) were very similar and [θ] of poly(UHPA) showed smaller than that of poly(DHPA). Although the pendant alkyl groups of poly(OcHPA) and poly(EHHPA) had the same carbon numbers, poly(OcHPA) with linear alkyl chains was soluble and poly(EHHPA) with branched alkyl chains was insoluble, suggesting that the more than eight of the carbon number of the backbone in the alkyl groups are needed to prevent the polymer chains from interacting with each other with hydrogen bonds.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We have investigated in detail the effect of the bulkiness of catalyst, and monomers on the helix-sense-selective polymerization of (4-ethynylphenyl) hydrogalvinoxyl (EPHG) using the Rh-catalyst in the presence of optically active 1-phenylethylamine (PEA). Monomers EPAcG and EPPEAG, whose hydroxyl group was protected by acetyl group or (R)-PEA moiety compared to EPHG, polymerized as well to give poly(EPAcG) and poly(EPPEAG), respectively, which showed clear and similar Cotton effects in tetrahydrofuran solution. The CD patterns of polymers obtained by [Rh(nbd)Cl] 2 and [Rh(cod)Cl] 2 were mirror image of each other in spite of the same chiral condition, i.e. in the presence of (R)-PEA. This fact indicates that the helix sense was controlled by achiral diene-ligands.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We synthesized one-handed helical poly[(4-ethynylphenyl)hydrogalvinoxyl] (poly(EPHG)) by helix-sense-selective polymerization using [Rh(nbd)Cl] 2 and [Rh(cod)Cl]2 catalyst in the presence of (R)-(+)-1- or (S)-(-)-1phenylethylamine (PEA). The [Rh(cod)Cl]2catalyst system gave red polymers whose CD spectra showed the stronger Cotton effect though the yield (2∼3%) and molecular weight (Mn = 1.1∼104) were lower than those of polymers obtained by [Rh(nbd)Cl]2. The CD patterns of polymers obtained by [Rh(nbd)Cl]2and [Rh(cod)Cl] 2were mirror image of each other in spite of the same chiral condition, i.e. in the presence of (R)-PEA. This fact indicates that the helix sense on the helix-sense-selective polymerization was able to be controlled by the bulkiness of achiral diene ligand.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

The stability, stimuli-responsibility and degradability of chiral helical poly(4-dodecyloxy-3,5-bis(hydroxymethyl)phenylacetylene) (poly(DHPA)) were investigated. In solution, the molar ellipticity of poly(DHPA) ([θ]) depended on temperature or the polarity of solvent. This findings suggested the chiral helical structure was maintained by only intramolecular hydrogen bonds between neighboring side chains. In solid states, the weight-average molecular weight (Mw) of poly(DHPA) unchanged until 200deg
C, and no [θ] was observed when Mw was under 1.0 × 105.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Phthalocyanine Zinc (II) (ZnPc) was found to be adsorbed well into a Nafion (Nf) film. The adsorption isothermal was analyzed using BET equation suggesting a multi-layer adsorption mode. The adsorption of ZnPc into the Nf film was significantly regulated by simple pretreatments of the Nf film such as immersing in solvents and storage under solvent vapors. The regulation was explained by tunable physical and chemical properties of hydrophilic ionic cluster region formed by sulfonate groups, counter cations and solvent molecules for mass and ion transport in the Nf film.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We synthesized chiral/achiral phenylacetylenes with two hydroxy groups and obtained copolymers in various feed ratios. The copolymers showed large specifie rotation and strong Cotton effect even in small chiral monomer contents. This phenomenon can be explained by the "sergeants and soldiers" behavior and might be attributed to the transport of a chiral information into the entire main chain because of the enhanced chain rigidity through intramolecular hydrogen bonds. For comparison, we also report on the optical properties of the poly(phenylacetylene) containing methyl groups instead of hydroxymethyl groups.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

4-Dodecybxy-3,5-bis[(dimethyl)hydroxysilyl]phenylacetylene (DHSPA) was synthesized and copolymeried with 4-dodecybxy-3,5-bisChydroxymethy]) phenylacetylene (DHPA) using a chiral catalytic system. To fix the chiral helical structure of the obtained copolymers, condensation between silanol and alchol was carried out. In IR spectra of the resulting copolymer, new peaks attributed to Si-OSi and Si-OC bonds appeared. The molar ellipticity of the resulting copolymer hardly decreased when the polarity of solvent increased (CHCl3/DMSO = 10/1). The finding suggested the chiral helical structure was maintained by covalent bonds, Si-OSiorSi-OC.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

Two new chiral helical poly(hydroxyl-containing phenylacetylene) membranes without the coexistence of any other chiral moieties were prepared in the following manner: 1) Synthesis and homo- or co-polymerization of two new chiral pinanylsiloxy-containing phenylacetylenes, 2) Depinanylsilylation of the preformed polymer membranes in-situ. Complete depinanylsilylation was successfully achieved by treating with trifluoroacetic acid. The resulting membranes exhibited circular dichroism despite the absence of the chiral substituants, the fact indicating that the main chains of the polymers retained their chiral helicity. This is the first method to synthesizing such chiral poly(phenylacetylene) membranes. Furthermore we examined enantioselective permeation by using the obtained membranes. As a result, the importance of the contribution of the chiral main chain on enantioselective permeation was directly confirmed for the first time. In addition, since some of the depinanylsilylated membranes were insoluble in organic solvents, we could use them as an separation membrane for a toluene solution of a racemate.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We synthesized chiral/achiral phenylacetylenes with two hydroxyl groups and obtained copolymers in various feed ratios. The copolymers showed large specific rotation and strong Cotton effect even in small chiral monomer contents. This phenomenon can be explained by the "sergeants and soldiers" effect and might be attributed to the transport of the chiral information into the entire main chain because of the enhanced chain rigidity through intramolecular hydrogen bonds. In the CD spectrum of poly(phenylacetylene) having chiral pinanyl groups and two hydroxyl groups (poly(1)), the Cotton signal showed a reversible shifting as changing the polarity of solvent Poly(1) afforded a free-standing membrane by solution casting method, and then we carried out the desilylation of poly(1) in the membrane state to obtain the chiral helical poly(phenylacetylene) membrane without the coexistence of any other chiral source. The desilylated polymer membranes showed enantioselective permabilities despite the absence of the chiral groups due to the presence of the helical main chain.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

The stability, stimuli-responsibility and degradability of chiral helical poly(4-dodecyloxy-3,5-bis(hydroxymethyl)phenylacetylene) (poly(DHPA)) were investigated. In solid states, the weight-average molecular weight and the molar ellipticity ([θ]) of poly(DHPA) significantly decreased at the range of 200 to 225°C which was higher temperature than other poly(phenylacetylene)s bearing no hydrogen bonds. In solution, [θ] of poly(DHPA) depended on temperature or the polarity of solvent. Poly(DHPA) was less degradable in air than similar poly(phenylacetylene)s having octyloxy or decyloxy groups on 4-position.

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (international conference proceedings)  

We synthesized chiral helical polymeric membranes containing carboxyl/amino groups by in-situ desubstitution of poly(phenylacetylenes) membranes having chiral ester/carbamate moieties. The resulting membranes exhibited circular dichroism despite the absence of the chiral substituents, the fact indicating that the main chains of the polymers retained their chiral helicity. Furthermore we examined enantioselective permeation of various racemic amino acid (0.50 wt% aqueous solutions) by using the obtained membranes containing carboxyl/amino groups. The desubstituted membranes showed enantioselectivity in the permeation of racemic amino acid. This result indicates that chiral helicity of the polymers were retained despite the absence of the chiral substituents. The desubstituted polymeric membranes having carboxyl/amino groups showed larger permeability coefficients in the permeations of hydrophilic amino acids.

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

We have examined the role of the chiral amine cocatalyst in the recently discovered helix-sense-selective polymerization of a phenylacetylene using a catalytic system consisting of an achiral rhodium complex ([Rh(norbornadiene)Cl](2)) as the catalyst and a chiral amine as the cocatalyst. Several chiral amines were effective for the polymerization reaction and their effectiveness depended on their bulkmess and coordination ability to rhodium. The sense selectivity of the polymerization increased with the concentration of the chiral amines. To discuss the structure of the true active species in the catalytic system, we have synthesized a new chiral rhodium complex having two chiral amines as ligands ([Rh (norbomadiene) (chiral amine)(2)]+BF4-). The isolated chiral complex also catalyzed the helix-senses-elective polymerization. These findings suggest that a chiral rhodium complex having two chiral amines may be the true active species when using the catalytic system consisting of [Rh(norbornadiene)Cl](2) and a chiral amine. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2004.09.046

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

To develop better polymeric materials for optical-resolution membranes, we synthesized nine chiral phenylacetylenes containing pinanyl groups. We used them to investigate the effects of chemical structures, including the number and position of the chiral groups in the monomers, on the induction of chirality in the main chain during polymerization and on the degree of enantioselectivity in the permeation of the polymeric membranes. The monomers included six new chiral p-(oligomethylpinanylsiloxanyl)phenylacetylenes. The homopolymerizations of these nine monomers with a Rh complex produced high-molecular-weight polymers (molecular weight = 10(5)-10(6)). Of the five polymers with a chiral pinanyl group at the 1-position of each oligosiloxanyl group, all except for two polymers showed high molar ellipticity in the main-chain region in the circular dichroism spectra. This finding indicated that these polymers had a chiral helical main chain. The membranes fabricated from all the polymers synthesized in this study were high-quality, except for two polymers. All these membranes showed enantioselective permeabilities for two amino acids and an alcohol. The membranes from the polymers with a chiral helical backbone, a high content of pinanyl groups, no oligodimethylsiloxane moieties, or a combination of these showed good enantioselectivities ( = 1.7-640) in permeation. We propose that the sense of the main-chain helicity determined the selectivity. (C) 2004 Wiley Periodicals, Inc.

DOI： 10.1002/pola.20356

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

We succeeded in introducing cation exchange groups quantitatively into a porous resin having an open-celled monolith structure. The resulting new cation exchange resin had the following advantages compared with conventional ion exchange resins having a bead structure. First, it was easier to pack it in a column. Second, the ion exchange rate of the new cation exchange resin was much higher than that of the conventional ion exchange resins, and the ion exchange band length of the new resin was smaller than that of the conventional ones. In addition, the electric conductivity was about five times higher than that of the conventional ones, although they had similar ion exchange capacities. These unique properties of the new cation exchange resin were caused by the quantitative introduction of ion exchange groups into the resin having the open-celled monolith structure. (C) 2003 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2003.10.097

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

We successfully introduced ion exchange groups quantitatively into a porous resin having an open-celled monolith structure. The resulting new ion exchange resin had the following advantages compared with conventional ion exchange resins having a bead structure. First, it was easier to pack it in a column. Second, the ion exchange rate of the new ion exchange resin was much higher than that of the conventional ion exchange resins, and the ion exchange band length of the new resin was smaller than that of the conventional ones. Third, the electric conductivity was about five times higher than that of the conventional ones, although they had similar ion exchange capacities. These unique properties of the new ion exchange resin were attributable to the quantitative introduction of ion exchange groups into the resin having the open-celled monolith structure. In addition, many kinds of ion-exchange resin monoliths from soft ones to hard ones were able to be prepared by changing the ratio of DVB.

DOI： 10.1295/koron.61.301

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

光学活性なピナニルジメチルシリル基を1つまたは2つ有するジフェニルアセチレンの共重合によりピナニル基を多く含むポリ(ジフェニルアセチレン)の高重合体を収率良く合成した。これらのキャスト膜を酸処理することで脱ピナニルシリル化し、光学活性な分子空孔を有する膜を調製した。光学活性な分子空孔を有する膜が不斉認識能を示すことが明らかとなった。

DOI： 10.1021/ma035493h

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Charge transport (CT) in a Nafion film incorporating [(NH3)(5)Ru(mu-pz)Ru(NH3)(5)](4+) ([Ru-II-Ru-II](4+); pz = pyrazine) was studied using a double potential-step chronoabsorptometry (DPSCA) technique. The oxidative CT by [Ru-II-Ru-II](4+)/[Ru-II-Ru-III](5+) (in a potential step from -0.2 to 0.3 V; first step) was compared with that by [Ru-II-Ru-III](5+)/[Ru-III-Ru-III](6+) (in a successive potential step from 0.3 to 0.7 V; second step). The predominant CTs by a physical displacement mechanism of the complexes were suggested for both of the steps. However, the rate constant of the CT for the first step was 5.2 time higher than that for the second step at 25 degreesC. The results on CT kinetics and dynamics revealed that the CTs in both of the steps are entropy-controlled in the activation at room temperature. The DeltaH(double dagger) (12 kJ mol(-1)) for the physical displacement in the second step was lower than that (24 kJ mol(-1)) for the first step, showing that the physical displacement for the second step is enthalpically favorable compared with that for the first step. The corresponding DeltaS(double dagger) (-234 J K-1 mol(-1)) for the second step is lower than that (DeltaS(double dagger) = -184 J K-1 mol(-1)) for the first step, making the physical displacement for the second step more entropically difficult than that for the first step. The entropy effect on the physical displacement was discussed on the basis of the interaction of the complexes with Nafion and reorganization of the solvent (water) molecule involved in the process. The DeltaS(double dagger) for the physical displacement of redox complexes in the film decreased with the positive charge of the complexes, suggesting that the highly positive-charged complex is entropically unfavorable for physical displacement, presumably due to higher degree of solvation of the complex and the sulfonate groups in their dissociation.

DOI： 10.1021/jp036146c

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We synthesized monomers of poly(9,10-anthryieneethynylene)s which were anthracene derivatives substituted with one or two phenol residues at the P-position. The monomers were polymerized by Pd(0) catalyst to give the corresponding precursor polymer with (M) over bar (n) approximate to 5 X 10(3). The polyradicals were synthesized by oxidation of the hydroxyl group. The magnetization plots of the polyradicals showed that the average ground state spin quantum number of the polyradical with two pendant phenoxyls in one anthracene unit (S = 5/2) became larger than that of the polyradical with one pendant phenoxyl (S = 2/2) at the same spin concentration (spin cone.;approximate to 0.35 spin/phenoxyl unit). The statistical simulation of the ground spin states supported that this behavior was caused by ladder-like spin coupling network of the polyradical with two pendant phenoxyls in one anthracene unit. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0277-5387(03)00251-1

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

A poly(9,10-anthryleneethynylene)-based polyradical with pendant stable phenoxyls was newly synthesized via polymerization of the corresponding bromoethynylanthracene monomer using Pd(0) catalysts. The average molecular weight of the polymer reached M-n = 5 x 10(3) by the polymerization reaction for a few hours, and the polymer was soluble in common organic solvents. The polyradical was prepared from the corresponding hydroxyl precursor polymer and was appropriately stable at room temperature. The ESR spectrum of the polyradical suggested an effectively delocalized spin density distribution on the backbone anthracene. The magnetization and the static magnetic susceptibility of the polyradical were measured using a SQUID magnetometer, and the results revealed moderately strong ferromagnetic spin coupling (2J = 39+/-3 cm(-1)) through the pi-conjugated chain, depending on the degree of spin density distribution on the anthracene backbone.

DOI： 10.1021/cm020317t

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Three optically;active phenylacetylene polymers with chiral bulky pinanyl groups, (-)-poly [4-(dimethylpinanylsilyl)phenylacetylene] [(-)-poly(PSPA)], (+)-poly{4-[3-(10-pinanyl)tetramethyldisiloxy]phenylacethylene} [(+)-poly(PDSPA)], and their copolymer [(-)-copoly(PSPA/PDSPA)], were synthesized. We observed high chirality in the main-chain chromophore of (-)-poly(PSPA), due to the presence of a chiral helix, with circular dichroism spectroscopy. In contrast, (+)-poly(PDSPA),with flexible SiOSi spacers between the chiral pinanyl group and the main chain, had lower chirality. (-)-Poly(PSPA), with large circular dichroism signals, was prepared by polymerization with a rhodium catalyst and had a highly stereoregular main chain (high cis-configuration percentage). However, (-)-poly(PSPA) prepared with a tungsten catalyst had lower chirality and lower stereoregularity in the main chain. A membrane from (-)-poly(PSPA) showed enantioselective permeability for tryptophan in an aqueous solution. (C) 2002 Wiley Periodicals, Inc.

DOI： 10.1002/pola.10253

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

We synthesized two new poly(diphenylacetylene)s having two or three trimethylsilyl groups and found these membranes having extremely high oxygen permeabilities of more than 1000 barrers which are of the same order as that for poly[1-(trimethylsilyl)-1-propyne]. Whereas oxygen permeability of poly[1-(trimethylsilyl)-1-propyne] was reported to decrease largely with time, these high oxygen permeabilities were stable for several months. These membranes also showed ethanol permselectivities because of their hydrophobicity, It was found that the introduction of two or three trimethylsilyl groups to poly(diphenylacetylene) was very effective for obtaining stable high oxygen permeable and ethanol permselective membranes. (C) 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0032-3861(01)00739-X

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Highly hydrophilic interpenetrating polymer network (IPN) membranes were prepared from a mixture system of poly(4-vinylpyridine) (P4VP) and poly(vinyl alcohol) (PVA) by quaternizing crosslinking of P4VP with 1,4-dibromobutane (DBB) and simultaneous crosslinking of PVA with hexamethylene diisocyanate (HMDI). The membrane performance in pervaporation (PV) for the azeotropic mixture of ethanol with a less polar organic liquid (chloroform, benzene, carbon tetrachloride, and cyclohexane) was investigated. The strength of these IPN membranes was higher than that of the cellulose acetate membrane and depended on the membrane composition. All the membranes were ethanol permselective for the azeotropic feeds and equimolar mixture feeds as well. Only the swelling degree Q of the membrane, among several physicochemical factors, showed a relationship with the separation performance for the four feeds; a lower value of Q generally corresponded to a higher separation factor and smaller permeability. The membrane composition, which exhibited an optimum membrane performance, was examined in detail for some membranes. Both the separation factor for sorption and that for diffusion far exceeded unity, but the latter was greater in most cases than was the former and dominated the overall separation. (C) 2001 John Wiley & Sons, Inc.

DOI： 10.1002/app.2125

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

We synthesized monomers of poly(9,10-anthryleneethynylene)s which were anthracene derivatives substituted with one or two phenol residues at the beta -position which would receive less steric hindrance from the poly(9,10-anthryleneethynylene) backbone. The monomers were polymerized by Pd(0) catalyst to give the corresponding precursor polymer with (M) over bar (W) similar to 10(4). The polyradicals were synthesized by oxidation of the hydroxyl group. The clearer hyperfine structure of the corresponding monomeric radicals suggested that the polyradicals probably also involved an effectively delocalized spin density distribution into the anthryleneethynylene skeleton. Diradical models for the poly(9, 10-anthryleneethynylene)-based polyradicals were also synthesized, and the magnetic properties of diradicals suggested defect insensitive strong ferromagnetic spin coupling of the corresponding polyradicals. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0277-5387(01)00608-8

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Two optically active poly(menthoxycarbonylphenyleneethynylene)s were synthesized by polycondensation using a palladium-copper catalyst system. All polymers showed Cotton effects in the absorption region of the main chain, implying that chirality is induced to the main chain. Moreover, these chiral polymers showed the enantioselective recognition ability for chiral menthol in the circular dichroism (CD) spectra. (C) 2000 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0032-3861(00)00391-8

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Monodendrons consisting of in-linked phenyleneethynylene repeating unit with trimethylsilyl-, pentamethyldisiloxanyl-, and nonamethyltetrasiloxanyl- peripheral groups were synthesized using the convergent approach. The focal point of monodendrons, terminal acetylene, was polymerized with Rh catalyst to give the corresponding polydendrons with a high molecular weight, e.g., (M) over bar (w) = 2.8 x 10(6) ((DP) over bar = 2.8 x 10(3)). The polydendrons showed good solubility in common organic solvents, and good membrane forming ability. Since we obserbed high ratio of a peak at delta 5.8-6.0, assignable to cis proton of poly(phenyl acetylene) main-chain, in H-1 NMR of the polydendrons, the polydendrons were found to be cis-rich polymer. The visible absorption maxima (lambda(max)) of the polydendrons significantly increased due to effect of the bulky substituents at in-position in comparison with the corresponding zero generation of poly(phenylacetylene) derivatives having no substituents at in-position. The wide angle X-Ray scattering of the polymers suggested the pseudohexagonal lattice of rod-like molecules. The interplanar d spacing increased with increasing generation or size of the peripheral silyl group.

DOI： 10.1295/polymj.33.879

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

Poly(phenylacetylene) and polystyrene which contain galvinoxyl and trimethylsilyl units were synthesized by copolymerization of the corresponding monomers or polymer reaction of the corresponding methyl benzoate polymers with [3,5-di-tert-butyl-4-(trimethylsiloxy)-phenyl]lithium. The copolymers obtained from (4-trimethylsilyl)phenylacetylene and (4-ethynylphenyl)hydrogalvinoxyl using [Rh(norbornadiene)Cl](2) catalyst had very high molecular weights. On the contrary, the copolymers of (4-trimethylsilyl)styrene and methyl 4-vinylbenzoate nearly completely reacted with [3,5-di-tert-butyl-4-(trimethylsiloxy)phenyl]lithium to give the corresponding galvinoxyl-copolymers with high molecular weights. The hydrogalvinoxyl could be fabricated to self-supporting membranes. We succeeded in obtaining such stable polyradical membranes that the initial spin concentration was maintained for a few days. The oxygen permselectivity (alpha = P-O2/P-N2) increased and the oxygen permeability (P-O2) decreased as galvinoxyl units increased, owing to the rigid character of galvinoxyl moiety. (C) 2000 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0032-3861(99)00693-X

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

Charge transport in a Nafion(R) membrane incorporating zinc(II) phthalocyanine (ZnPc) was studied using spectrocyclic voltammetry (SCV) and potential-step chronocoulospectrometry (PSCCS) techniques. The visible absorption spectra of the membrane depended on the ZnPc concentration in the membrane, showing the formation of the ZnPc dimer. The equilibrium constant between the monomer and dimer of ZnPc in the membrane was calculated as 75 M-1. Tt was found that the charge transport occurs by two processes; the first process was considered to be the charge injection from the electrode to the ZnPc present in close proximity to the electrode, and the second one, bulk charge transport in the membrane. The apparent rate constant for the presumed charge injection was estimated as 1.6 x 10(-2) s(-1). The bulk charge transport in the membrane was analyzed as a combination of a physical displacement of ZnPc and charge hopping between them considering the equilibrium between the monomer and dimer of ZnPc. This analysis shows that the charge transport takes place by physical displacement of the ZnPc monomer and not by charge hopping, and that the contribution of the dimer to the charge transport is negligible. The first order rate constant (k(p)) of the physical displacement of the ZnPc monomer was estimated as 3.3 x 10(-3) s(-1). The saturated fraction of the oxidized ZnPc in the membrane decreased with the ZnPc concentration in the membrane because of the bulk charge transfer decreased by the formation of the ZnPc dimer. (C) 2000 Elsevier Science S.A. All rights reserved.

DOI： 10.1016/S0022-0728(99)00488-X

Web of Science

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：John Wiley & Sons Ltd  

We synthesized monodendrons and macrocyclic compounds consisting of phenyleneethynylene repeating units, which have a precisely defined three-dimensional structure. They have a terminal acetylene group, and were successfully polymerized with a rhodium catalyst to give the corresponding polydendrons and polymacrocycles with high molecular weight in spite of their bulky dendritic and macrocyclic residue. The polydendrons and polymacrocycles with a high degree of polymerization have good membrane-forming ability, and were available for oxygen-permselective membrane. Copyright (C) 2000 John Wiley and Sons, Ltd.

DOI： 10.1002/1099-1581(200008/12)11:8/12<685::AID-PAT20>3.0.CO;2-7

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

We synthesized a dendritic phenylacetylene monomer containing tert-butyl groups as the peripheral groups using the coupling reaction between 4-(3,5-dibromophenyl)-2-methyl-3-butyn-2-ol and phenylacetylene derivatives followed by the elimination of terminal acetylene-protecting group. The dendritic macromonomer was polymerized with a rhodium catalyst to yield the corresponding poly(phenylacetylene) derivative as a yellow powder. The polymer possessed a high degree of polymerization, e. g., (DP) over bar =1.0x10(3), in spite of the steric bulkiness of pendants. The unexpectedly high molecular weight of the polydendron can be explained as follows. The terminal acetylene was exposed from dendritic crowd, and the polymerization proceeded stereoregularly to give the reasonable packing of the sidechain dendrons. The polymers were soluble in common organic solvents such as chloroform and tetrahydrofuran, but insoluble in alcohols, and the solubility of these polydendrons was better than that of the corresponding zero generation poly(phenylacetylene) derivatives.

DOI： 10.1295/koron.57.672

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

An optically active polyradical was first synthesized by copolymerization of (4-ethynylphenyl)hydrogalvinoxyl and chiral acetylene monomer using Rh-catalyst. The circular dichroism spectrum of the polyradical showed a Cotton effect indicating the, exess of one-handed helix backbone and the induced chirality of side-chain galvinoxyl units. Intermoleculer antiferromagnetic interaction observed for the polyradical was larger than that of the corresponding polyradical without excess of one-handed helix.

DOI： 10.1246/cl.1999.623

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Disubstituted acetylenes with chiral pinanyl groups, (-)-1-{4-[dimethyl(10-pinanyl)silyl]phenyl)-2-phenylacetylene (1), (-)-1-{3-[dimethyl(10-pinanyl)silyl]phenyl}-2-phenylacetylene(2), (-)-1-{4-[dimethyl(10-pinanyl)silyl]phenyl}-1-propyne (3), and (-)-1-chloro-2-(4-[dimethyl( 10-pinanyl)silyl]phenyl)acetylene (4), polymerized with NbCl5-, TaCl5-, or MoCl5-based catalysts to give high molecular weight polymers in good yields. Poly(1) and poly(a) showed intense circular dichroism (CD) effects in the UV-vis region and large optical rotations, which suggests that these polymers exist in helical conformations with an excess of one-handed screw sense. No significant decrease in the magnitude of CD effects of poly(1) and poly(a) with increasing temperature indicated the relatively high stability of their helical conformations. On the other hand, the intensities of CDs of poly(3) and poly(4) were approximately 1/10 those of poly(1) and poly(a), which means that introduction of two aromatic side groups into the repeating unit is favorable for the induction of helical conformation to disubstituted acetylene polymers. The free-standing membranes of poly(1), poly(a), and poly(3) exhibited characteristic properties as gas-permeable and optical resolution membranes.

DOI： 10.1021/ma9810969

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

4-[(3,5-Di-tert-butyl-4-hydroxyphenyl)(3 2,5-di-tert-butyl-4-oxo-cyclohexa-2,5-dienylidene)methyl]styrene (abbreviated as (p-vinylphenyl)hydrogalvinoxyl) was polymerized using AIBN as an initiator to give a bright yellow polymer with &lt;(M)over bar (w)&gt; = 3.2 x 10(4). The polymer was oxidized to give the corresponding polyradical derivative, whose spin concentration could be increased up to about 70 mol % depending on oxidative conditions. ESR signal line-width in the solid state was greatly increased below 200 K for the polyradical with a high spin concentration (&gt; 50 mol %). The magnetization and magnetic susceptibility indicated weak antiferromagnetic interaction among the radical sites. (C) 1999 John Wiley & Sons, Inc.

DOI： 10.1002/(SICI)1099-0518(19990115)37:2<189::AID-POLA9>3.3.CO;2-Q

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：GORDON BREACH PUBLISHING, TAYLOR & FRANCIS GROUP  

The bromoethynylanthracene monomer with 3,5-di-tert-butyl-4-acetoxyphenyl group was newly synthesized and was polymerized by Pd(0) catalyst to give the head-to-tail regulated polymer with DP = 12. The ESR spectra of the anthracene-based polyradical suggested an effectively delocalized spin distribution an the backbone anthracene. The Delta m(s) = +/-2 forbidden transition ascribed to the triplet species was observed at g = 4 in frozen toluene glass. Magnetization and static magnetic susceptibility of the polyradical were measured using a SQUID magnetometer. The average spin quantum number was beyond S = 1/2, indicating the ferromagnetic interaction.

DOI： 10.1080/10587259908023320

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JOHN WILEY & SONS INC  

Semi-interpenetrating (SPN) and interpenetrating polymer network( IPN) membranes were prepared from a mixture system of poly( 4-vinylpyridine) (P4VP) and poly(glycidyl methacrylate) (PGMA) by quaternizing crosslinking of P4VP with 1,4-dibromobutane (DBB) and by simultaneous crosslinking of P4VP with DBB and PGMA with tetraethylenepentamine (TEPA), respectively. The difference between SPN and IPN was demonstrated by IR, tensile strength, and dimension stability. The membrane performance in pervaporation (PV) for ethanol-water mixtures and reverse osmosis (RO) was investigated. The polymer mixture of 1 : 1 on a monomer base with 30 mol % DBB on the 4VP unit and 5.6-7.5 mol % (8-10 wt %) TEPA on the GMA unit gave an optimum membrane performance. Those crosslinked membranes were stronger than was the cellulose acetate membrane, mostly owing to the PGMA chains, and exhibited a high separation factor for the azeotropic feed in PV. IPN membranes generally showed a performance higher than that of the SPN ones. An attempt to improve the product rate was made by the addition of a water-soluble polymer to the membrane on casting. The separation factor for solubility in the membrane at the feed side dominated the overall separation factor, particularly for feeds of`higher ethanol concentrations. (C) 1998 John Wiley & Sons, Inc.

DOI： 10.1002/(SICI)1097-4628(19980906)69:10<1953::AID-APP7>3.0.CO;2-D

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

フェニルアセチレンを繰り返し単位とするモノデンドロンを合成し、末端アセチレンをロジウム錯体触媒で重合した。側鎖にかさ高い置換基を持つにも関わらず重合は進行し、重合条件により重合度数千におよぶポリデンドロンが得られた。中心核を高分子鎖にすることで棒状あるいは太い線状の構造体を構築し、デンドリマーの特徴を持ったまま高分子特有の性質を賦与した。

DOI： 10.1021/ma9616975

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCI LTD  

A novel norbornadiene polymer having optically active pinanyl groups in the pendant groups was synthesized as an optical resolution membrane material. The resulting polymer membrane showed highly enantioselective permeability for racemic propranolol used as a medicine. The permeability of tryptophan was much higher than that of a (+)-poly{1-[dimethyl(10-pinanyl)silyl]-1-propyne} membrane we reported previously. Copyright (C) 1996 Elsevier Science Ltd.

DOI： 10.1016/S0032-3861(96)00630-1

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Since optically active poly(methylpinanylsilane) synthesized by Na-mediated polycondensation of the corresponding dichlorosilane showed an Cotton effect at the UV region of Si sigma-Si sigma* transition of the main chain in the circular dichroism (CD) spectrum, the main chain was found to have a chirality. The Cotton bands in the presence of the (+)-isomer of a hydrophobic compound were different from those in the presence of the (-)-isomer. Therefore, this polymer was found to have an ability of the enantioselective recognition. On the other hand, a hydrophilic compound did not affect the CD band. These findings indicate that the recognition was caused mainly by hydrophobic diastereomeric interaction between the chiral compound and the chiral main chain in this polymer.

DOI： 10.1246/cl.1997.361

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

アモルファスなスピン配列の混合体である一次元高スピンポリラジカルについて、パルスESRを用いたESTN法により、各々のスピン配列種のスピン量子数について分離観測した。少なくとも、S=1以上の成分が混合して存在していることが明らかとなった。

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Chemically stable poly[2-(3,5-di-tert-butyl-4-oxyphenyl)-1,4(p)-phenylenevinylene], poly[4-(3,5-di-tert-butyl-4-oxyphenyl)-1,3(m)-phenylenevinylene], and poly[4-(3,5-di-tert-butyl-4-oxyphenyl)-1,2(o)-phenylenevinylene] were synthesized via the polymerization of 4-bromo-2-(3,5-di-tert-butyl-4-acetoxyphenyl)styrene, 5-bromo-2-(3,5-di-tert-butyl-4-acetoxyphenyl) styrene, and 2-bromo-4-(3,5-di-tert-butyl-4-acetoxyphenyl) styrene, respectively, using a palladium catalyst. The o- and p-polyradicals, even with their spin concentration of 0.6 spin/unit, displayed S values of 4/2 to 5/2 (S = 5/2 for the o-polyradical with a degree of polymerization of 17 and a spin concentration of 0.68), while the m-polyradical has a singlet ground state. A long-range intramolecular through-bond ferromagnetic exchange interaction was realized between the pendant unpaired electrons for the o- and p-polyradicals, in accordance with theoretical predictions based on the molecular connectivity. The average value of the exchange coupling constant for the o-polyradical, 2 (J) over bar = 48 +/- 6 cm(-1), was larger than 2 (J) over bar = 32 +/- 2 cm(-1) for the p-polyradical, while they were almost coincident with or much larger than the exchange coupling constants for the corresponding diradical model compounds. Both force field calculations and spectroscopic results indicated a less hindered steric structure with a planarized pi-conjugated skeleton for the o-polyradical.

DOI： 10.1021/ja961721u

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Optical resolution of various racemates such as (+/-)-tryptophan and (+/-)-1,3-butanediol was achieved by permeation through a self-supporting membrane of (+)-poly{1-[dimethyl(10-pinanyl)silyl]-1-propyne} [(+)-poly(DPSP)] prepared by homopolymerization of (-)-1-[dimethyl(10-pinanyl)silyl]-1-propyne [(-)-DPSP]. Almost complete optical resolution (% ee of the permeate = 81-100% ee) was achieved at an initial period of concentration-driven permeation, and stable permeation with moderate permselectivity (% ee of the permeate = 12-54% ee) continued for more than 600 h. In addition, by permeation of vapor permeant such as evapomeation and pervaporation, higher permeation rates were attained maintaining high enantioselectivity. The sign of the enantiomer that predominantly permeated through a (+)-poly(DPSP) membrane was opposite to that through a (-)-poly(DPSP) membrane. In the permeation through a (+)-poly(DPSP) membrane of a solute or a solvent having a high affinity for (+)-poly(DPSP) and in the permeation through a membrane from the copolymer of (-)-DPSP with a small amount of 1-(trimethylsilyl)-1-propyne, their enantioselectivities were much lower. These findings suggest that the permeating route surrounding chiral pinanyl groups in a (+)-poly(DPSP) membrane that can enantioselectively separate various racemates was easily deformed by using a solute or solvent having a high affinity for (+)-poly(DPSP) or by removing a small amount of pinanyl groups.

DOI： 10.1021/ma9517254

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Poly[[2- or 4-[N-t-butyl-N-(triethylsiloxy- or t-butyldimethylsiloxy)amino]-1,4- or 1,2-phenylene]vinylene] was synthesized by polymerizing 4- or 2-bromo-2- or 4-[N-t-butyl-N- (triethylsiloxy- or t-butyldimethylsiloxy)amino] styrene with a palladium catalyst, respectively. They were deprotected and chemically oxidized to yield poly(1,4- or 1,2-phenylenevinylene)s bearing a 2- or 4-substituted built-in nitroxide radical. The polyradicals were chemically stable, and their spin concentration was increased to 0.8 spin/unit. A SQUID measurement which included the corresponding diradicals and triradicals indicated that a partial, but strong, intramolecular ferromagnetic coupling was established through the conjugated backbone, despite a spin defect in the side radical moiety, for the poly(1,2-phenylenevinylene) bearing 4-substituted built-in nitroxide radical.

DOI： 10.1246/bcsj.69.499

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

2,6-ジ-t-ブチルフェノール、t-ブチルニトロキシドなどが置換されたオリゴおよびポリ（フェニレンビニレン）誘導体の紫外光電子スペクトルを測定した。側鎖の立体効果によらず共平面性は維持され、イオン化ポテンシャルとバンドギャップの相関は置換基の構造に依存した。対応するポリラジカルでは大きなイオン化ポテンシャルの増大は認められず、共役系は維持されていた。

DOI： 10.1295/polymj.28.182

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：GORDON BREACH SCI PUBL LTD  

FT Pulsed ESR/Electron Spin Transient Nutation(ESTN) Spectroscopy has been, for the first time, extended to amorphous and powder states of materials. Recently, organic high-spin polymers and clusters have emerged. With the increasing molecular spin quantum number S and molecular weight of the polymers, cw ESR spectroscopy manifests its inherent disadvantages in discriminating high spins from S=1/2 and in determining the S's for the complex mixture of various spin assemblages. An electron spin transient nutation (ESTN) method based on pulsed ESR spectroscopy has been for the first time applied to a quasi 1D neutral high-spin polymers (A) as one of the most complex amorphous spin assemblages, identifying that the first neutral high-spin polymer A is comprised of high-spin assemblages characterized by the even S's greater than 1/2. The molecular quantum spin number S have been identified up to S=4, showing direct evidence of the occurrence of a high-spin polymer with a pi-topologically controlled spin polarization. Eelectron spin transient nutation spectroscopy is facile and useful method for the exclusive identification of S and ESR transitions even for the cases of apparently vanishing fine-structure splittings and for spin systems with residual fine-structure terms in the spin Hamiltonian Fundamental bases for the transient nutation method are described, emphasizing inherent advantages in the nutation spectroscopy from the methodological viewpoint. The salient feature of multiple-quantum nutations have been disclosed in this work.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Ferromagnetic spin coupling of the tert-butylnitroxide diradicals connected to the oligo(1,2-phenylenevinylene)-skeleton was studied to relate with their pi-conjugated electronic structure. The spin coupling constant (J) determined from their magnetic susceptibility increased with the degree of oligomerization in the conjugated skeleton and was reduced in response to the conjugated but spacing phenylenevinylene unit. These 2J values qualitatively agreed with the semiempirically calculated ones.

DOI： 10.1246/cl.1995.421

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

ポリアセチレンあるいはポリ（フェニレンビニレン）を主鎖骨格として、対応するラジカル前駆体モノマーを特定の有機金属触媒で重合し、ラジカルの置換位置と連結様式が一定の構造明確なポリフェノキシおよびポリニトロキシラジカルを合成した。高分子鎖内での電子状態、スピン相関および磁気的性質を分光法および磁気測定により解析し、有機高分子で強磁性体を設計するための一つの手順を明らかにしている。

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

2,6-ジ-t-ブチルフェノキシルを置換したポリ（1,4-および1,2-フェニレンビニレン）を合成し、電子状態と磁気的性質について分子構造と関連させて議論した。磁化測定値のBrilouin関数へのフィッティングでは、平均スピン量子数はS=4/2を超え、構造明確なポリラジカル高分子としては前例のない高いスピン多重度を実現できた。

DOI： 10.1021/ja00106a070

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The electrochemical oxidation and reduction of the stable neutral nitroxyl radical gave the oxoaminium salt and hydroxylamine or nitroxyl anion, respectively. The electrochemical behavior of the N‐butylnitroxyl radicals or N‐butylhydroxylamines built in to various phenylenevinylene species were discussed in connection with its developed π‐conjugated structure based on cyclic voltammetric measurements. The aromatic nitroxyl radical showed two pairs of oxidation–reduction waves, but the acidic proton (hydroxylamine) changed its cathodic peak to a broad one with a shift to the anodic side. The π‐conjugated poly(phenylenevinylene) backbone and mobile proton of the hydroxylamine unstabilized the nitroxyl radical by retaining the energy gap. Copyright © 1995 John Wiley &amp
Sons, Ltd.

DOI： 10.1002/pat.1995.220061105

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：GORDON BREACH SCI PUBL LTD  

The poly(phenylenevinylene) skeleton was selected as a magnetic coupler of polyradicals, because of its developed pi-conjugation, coplanarity, and solvent-solubility even after substitution on the phenylene ring. By synthesizing poly(1,4- or 1,2-phenylenevinylene)-2- or -4-substituted with a stable phenoxy or nitroxy radical, an intramolecular, through-bond and long-range, but strong, ferromagnetic exchange interaction was realized for the first time. The polyradicals were chemically stable and, even at their spin concentration of ca. 0.5, displayed (S) over bar values of 2/2 similar to 4/2.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：GORDON BREACH SCI PUBL LTD  

Poly(phenylenevinylene)s with built-in radical groups are expected to show magnetic interaction caused by spin polarization and/or coplanarity of the pi-conjugated chain. Diradical models for the poly(phenylenevinylene)-based polyradicals were synthesized, and the magnetic properties were discussed based on ESR spectra and magnetic measurement. Magnetization and magnetic susceptibilities of the polyradicals, tert-butylnitroxyl- and 2,6-di-tert-butylphenoxyl-substituted poly(1,2- or 1,4-phenylenevinylene), indicated the occurrence of ferromagnetic interaction corresponding to these oligomeric diradicals.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：GORDON BREACH SCI PUBL LTD  

As a novel high-spin molecule, a through-bond spin-frustrated organic molecule 4, 4', 4 ''-trisdiphenylmethyleneamine (TDMA) and its anion and cation was studied by cw-ESR spectroscopy. TDMA is a spin frustrated system composed of three S=1 units coupled antiferromagnetically. This molecule was shown to have a triplet ground-state which is asymmetrical in its exchange interaction as well as its molecular conformation. The TDMA ions were generated at low temperature via successive radiolysis and photolysis of its diazo precursor. It was shown that the ground states of the anion and cation are quartet and sextet, respectively. This means that upon ionization the ground state changed from the intermediate-spin state of TDMA to the high-spin state of the ions, showing the interrelation between spin alignment and excess charge in a molecular field. On the other hand, in order to identify and discriminate the spin multiplicities of complicated spin assemblages in amorphous materials, we have developed electron spin transient nutation spectroscopy based on FT pulsed ESR and applied it to a pseudo one-dimensional high-spin polymer with effective spin S greater than or equal to 2.

DOI： 10.1080/10587259508034046

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：GORDON BREACH SCI PUBL LTD  

Recently, organic high-spin polymers and clusters have been emerging. With the increasing effective molecular spin quantum number S and molecular weight of the polymers, however, cw ESR spectroscopy manifests its inherent disadvantages in discriminating high spins from S=1/2 and in determining the S's for the complex mixture of various spin assemblages. An electron spin transient nutation method based on pulsed ESR spectroscopy has been for the first time applied to a quasi 1D high-spin polymer as one of the most complex amorphous spin assemblages, identifying that the polymer is comprised of high-spin assemblages with the S's greater than two. It can be concluded that electron spin transient nutation spectroscopy is a facile and useful method for the exclusive identification of S and ESR transitions even for the cases of apparently vanishing fine-structure splittings and for spin systems with residual fine-structure terms in the spin Hamiltonian. Fundamental bases for the transient nutation method are described, emphasizing inherent advantages in the nutation spectroscopy from the methodological viewpoint. The salient features of multiple-quantum nutations have been disclosed in this work.

DOI： 10.1080/10587259508034052

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Spectroscopical Society of Japan  

ポリ[4-(3,5-ジ-t-ブチル-4-オキシフェニル)-1,2-フェニレンビニレン]についてパルスESRの電子スピン緩和nutation法によりポリラジカルのスピン多重度を概算した。スピン量子数としては、S&gt;4/2の成分に相当するシグナルが観測された。

DOI： 10.5111/bunkou.43.280

CiNii Article

CiNii Books

researchmap

Other Link： https://jlc.jst.go.jp/DN/JALC/00029138883?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Poly(1,4- or 1,2-phenylenevinylene)s bearing a 2- or 4-substituted nitroxide radical were synthesized by polymerizing [bromo[N-tert-butyl-N-(trialkylsiloxy)amino]]-styrenes with a palladium catalyst. The polyradicals were chemically stable, and their ESR and SQUID measurements indicated an intramolecular and through-bond ferromagnetic coupling.

DOI： 10.1246/cl.1994.2135

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The electronic states of open-shell stilbene diradicals were st;hied. Previously used semiempirical MO-CI methods were applied to stilbenes having dimethylene, dioxyl, and dinitroxide centers in o,o'-, o,m'-, o,p'-, m,m'-, m,p'-, and p,p'-substitution patterns, and the various singlet-triplet energy gaps were computed to predict qualitative ground state spin multiplicities. Singlet and triplet spin states were essentially degenerate in the m,m'-isomers of disjoint connectivity, while nondisjoint o,m'- and m,p'-isomers had triplet computed ground states. Nitroxide-based diradicals showed considerably smaller computational exchange coupling energies than did other diradical models studied. As a tests of these computations, stilbenes with two N-tert-butyl nitroxide groups at the o,m'-, m,m'-, and m,p'-positions were prepared, and their magnetic properties were studied by ESR and-magnetic susceptibility measurements. The m,m'- and m,p'-isomers were found experimentally to have singlet and triplet ground states, respectively, in accord with the qualitative computed predictions.

DOI： 10.1021/jo00094a046

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The magnetic properties of poly(phenylacetylene)s with radical groups at the paraposition, poly[(3,5-di-tert-butyl-4-oxyphenyl)acetylene] (1),poly[[4-[(3,5-di-tert-butyl-4-oxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phenyl]acetylene] (2), and poly[[4-(N-tert-butyl-N-oxyamino)phenyl]acetylene] (3), were studied with a SQUID magnetometer. The magnetization and magnetic susceptibility indicated unexpected antiferromagnetic interactions between the radical sites. The exchange interaction observed in these conjugated polyradicals was discussed in connection with their computationally modeled structures.

DOI： 10.1021/ma00089a027

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Poly(methacrylic acid-co-triethyleneglycol dimethacrylate) adsorbed calcium ion effectively. The adsorption obeyed Langmuir's isotherm, which indicated adsorption site [-COO-]Ca-2(2+) and its stability constant (10(4) l/mol). The resin interacted with calcium of human tooth enamel, which was adhered with the resin.

DOI： 10.1295/koron.51.1

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Polyacetylene derivatives bearing chain-sided, Π-conjugated and bult-in phenoxy radicals were synthesized. They were soluble in common solvents and gave a transparent thin-film. ESR indicated partial derealization of the unpaired electron generated in the chain-sided group into the main chain. But any ferromagnetic interaction between the spins could not be observed. © 1993, Taylor &amp
Francis Group, LLC. All rights reserved.

DOI： 10.1080/10587259308054950

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Poly(phenylvinylene) and poly(phenylenevinylene) with tear-butyInitroxide as a built-in radical group were synthesized. Precursor polymers were obtained by the polymerization of the corresponding acetylene and styrene derivatives by Rh and Pd catalysts. They were soluble in common soivents and their chemical Oxidation under moderate condition gave the corresponding polyradicals. © 1993, Taylor &amp
Francis Group, LLC. All rights reserved.

DOI： 10.1080/10587259308035708

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

[4-(N-tert-Butyl-N-hydroxyamino)phenyllacetylene (7) was synthesized and polymerized to yield a solvent-soluble polyacetylene: poly[[4-(N-tert-butyl-N-hydroxyamino)phenyl]acetylene] (8). Oxidation of the polymer gave its radical derivative: the ESR spectrum showed a broad signal only in the DELTAm(s) = +/-1 region, and magnetic measurement with a SQUID magnetometer revealed an antiferromagnetic through-space interaction.

DOI： 10.1021/ma00069a023

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Abstract Poly(phenylvinylene) and poly(phenylenevinylene) with tert-butylnitroxide as a built-in radical group were synthesized. Precursor polymers were obtained by the polymerization of the corresponding acetylene and styrene derivatives by Rh and Pd catalysts. They were soluble in common solvents and their chemical oxidation under moderate condition gave the corresponding polyradicals.

DOI： 10.1080/10587259308035708

Web of Science

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

Photoreaction of camphorquinone (CQ) and dimethylaminoethyl methacrylate (DMAEMA) and its initiation capability of MMA polymerization was studied as a model system for visible light-cured dental composite resins. The photo-sensitizer (CQ) produced CQ radical anion by irradiation in the presence of the reducing agent (DMAEMA) under N2. ESR signal intensity and the IR and UV-Vis absorption spectra of CQ carbonyl group decreased during irradiation, and the polymerization rate of MMA depended on the decrease in the CQ carbonyl group. The hydrogen abstraction reaction by CQ radical seemed to promote the polymerization of MMA. Atmospheric oxygen inactivated the CQ radical and reduced the polymerization.

DOI： 10.1295/koron.50.485

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

[4-[(3,5-Di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phenyl]acetylene (6), was synthesized and polymerized to yield a solvent-soluble polyacetylene poly[[4-[(3,5-di-tert-butyl-4-hydroxyphenyl)(3,5-di-tert-butyl-4-oxocyclohexa-2,5-dien-1-ylidene)methyl]phenyl]acetylene] (5a). The polymer gave its polyradical derivative 5b through the chemical oxidation with active PbO2. 5b was stable, whose spin concentration could be increased up to 4.8 x 10(23) spins per molar monomer unit. ESR analysis indicated localization of unpaired electrons in the galvinoxyl residue. ESR analysis also suggested an exchange-narrowing and interpolymer dipole-dipole interaction.

DOI： 10.1021/ma00041a003

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

The polymerization behavior and photoinitiation process in the visible light‐cured dental composite resins were studied using ESR and IR spectroscopies. The concentration of methacryl propagating radical corresponded to the transmittance of irradiated light. While the radical was stable and long‐lived in the cured resin, its concentration quickly decreased in the oral cavity due to the ventilation of atmospheric oxygen accompanied by respiration. Camphorquinone radical in the presence of tertiary amine easily initiated the radical polymerization. A decrease in monomer consumption was explained by the inhibition effect of oxygen in the photoinitiation process. Post‐curing by the residual radical proceeded effectively in the deeper part of the resin. Copyright © 1992 John Wiley &amp
Sons, Ltd.

DOI： 10.1002/pat.1992.220030804

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MARCEL DEKKER INC  

Synthesis and magnetic properties of pi-conjugated stable polyradicals bearing a polyacetylene backbone are described. 2,6-Di-tert-butyl-4-ethynylphenol (8) and 4-ethynylphenylhydrogalvinoxyl (9) are polymerized with W, Mo chloride or Rh complex to yield their polyacetylene derivatives with molecular weight of ca. 10(4), while 2-ethynylphenalenone (10) gives only its oligomer. The polymers are soluble in common solvents and converted to the corresponding conjugated polyradicals via heterogeneous chemical oxidation using PbO2 or alkaline K3Fe(CN)6. The polyradicals with extremely high spin concentration (up to 4.8 x 10(23) spins/monomer mol) are obtained by regulating the oxidative conditions. The polyradicals are quite stable in solution and even in the solid state because of resonance stabilization and/or a steric effect of the substituents. Magnetic interactions between the unpaired spins in the conjugated stable polyradicals are discussed.

DOI： 10.1080/00222339108054091

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC POLYMER SCIENCE JAPAN  

2,6-ジ-t-ブチルフェノール、フェニルヒドロガルビノキシルのようなかさ高い置換基を有するポリアセチレン誘導体の紫外光電子スペクトルから、側鎖の立体効果により共役長がポリ(フェニルアセチレン)に比べ増大することを明らかにした。対応するポリラジカルでは、キノイド構造の生成により共役系が切断された。

DOI： 10.1295/polymj.23.921

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

フェニルヒドロガルビノキシル残基を有するポリアセチレンモノマーをロジウム錯体触媒で重合することで分子量数万のポリマーを合成した。このポリマーの水酸基を化学的に酸化することで、ユニットあたり0.8を超えるスピン濃度をもつポリラジカルの合成に成功した。

DOI： 10.1021/ma00222a028

Web of Science

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：電気化学会  

分子構造を精密設計・合成できるπ共役高分子ポリラジカルには、強磁性体のみならず新しい電磁機能が期待されている。本稿では、π共役分子を使ってお互いの電子スピンを強磁性的に整列させることを目指した最近のポリラジカル合成および磁気物性の進展について解説した。

DOI： 10.5796/electrochemistry.75.834

CiNii Article

CiNii Books

researchmap

Other Link： https://jlc.jst.go.jp/DN/JALC/00300958919?from=CiNii

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Japan Oil Chemists' Society  

DOI： 10.5650/oleoscience.6.443

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：高分子刊行会  

著者らが見出した主鎖のみに起因する不斉を持つ置換ポリアセチレン誘導体の合成法2つを解説した。ひとつはらせん選択重合、もうひとつは膜状態での脱キラル置換基による方法である。それぞれの合成法に適するモノマー構造などを考察した。

CiNii Article

CiNii Books

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

J-GLOBAL

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：高分子刊行会  

著者らによる光学活性基置換アセチレンのらせん不斉誘起重合の発見と展開を述べた。また、キラル触媒系によるアキラル置換アセチレンのらせん選択重合および置換アセチレン高分子の分離膜素材としての利点についても述べた。

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：化学工業社  

光学分割膜の分子設計について報告例を分類して紹介し、それぞれの現状と問題点を考察した。特に、著者らによる置換ポリアセチレンを用いた分子設計について詳しく紹介した。

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：The Society of Polymer Science, Japan  

DOI： 10.1295/kobunshi.50.153

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：高分子刊行会  

高分子ポリラジカルは、前駆体の重合を経た高分子反応によるラジカル生成あるいはラジカルモノマーの重合により合成された、高分子一分子鎖に複数の不対電子を有する高分子として位置づけられる。近年、この高分子ラジカルを用いた有機磁性材料への関心が高まっている。本稿では、磁性発現を目指した最近のポリラジカル合成および磁気物性の進展について解説した。

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：THE MEMBRANE SOCIETY OF JAPAN  

Several new polymers for optical resolution membranes were synthesized and enantioselective permeabilities of the polymer membranes were examined for various racemates using four methods, that is, concentration-driven permeatiom (CP), pressure-driven permeation (Δ P), pervaporation (PV), and evapomeation (EV). (+) -Poly (1- (dimethyl (10-pinanyl) silyl) -1-propyne) ((+) -poly (DPSP)) membranes showed high enantioselective permeabilities in CP for various racemates and low permeation rates, which were improved by using PV or EV. (-) -Poly (2- (dimethyl (10-pinanyl) silyl) norbornadiene) had a higher permeability than (+) -poly (DPSP). High and stable enantioselective permeations were observed through the graft copolymers with (-) -oligo (methyl (10-pinanyl) siloxane) as the grafts. Polymers having a chiral main chain showed enentioselective permeability

DOI： 10.5360/membrane.22.126

CiNii Article

CiNii Books

researchmap

Other Link： https://jlc.jst.go.jp/DN/JALC/00046930637?from=CiNii

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (other)  

CiNii Article

CiNii Books

researchmap

Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (other)   Publisher：Yuki Gosei Kagaku Kyokai  

Several new polymers for optical resolution membranes were synthesized and enantioselective permeabilities of the polymer membranes were examined for various racemates using four methods, that is, concentration-driven permeation (CP), pressure-driven permeation (Δ P), pervaporation (PV), and evapomeation (EV). (+)-Poly (1- (dimethyl (10-pinanyl) silyl)-1-propyne) ((+)-poly (DPSP)) membranes showed high enantioselective permeabilities in CP for various racemates and low permeation rates, which were improved by using PV or EV. (-)-Poly (2- (dimethyl (10-pinanyl) silyl) norbornadiene) had a higher permeability than (+)-poly (DPSP). Polymers having a chiral main chain showed poor enantioselective permeability. Highly and stably enantioselective permeations were observed through the blend membranes whose surface were modified by (-)-oligo- (methyl (10-pinanyl) siloxane ((-) -OMPS). The graft copolymers with (-) -OMPS as the grafts are promising for a higher performance membrane.

DOI： 10.5059/yukigoseikyokaishi.54.525

Scopus

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Kyoto International Conference Center, Kyoto, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Kyoto International Conference Center, Kyoto, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Kyoto International Conference Center, Kyoto, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Kyoto International Conference Center, Kyoto, Japan  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：熊本（熊本大学）  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：熊本（熊本大学）  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟（新潟大学五十嵐キャンパス）  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟（新潟大学五十嵐キャンパス）  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：新潟（新潟大学五十嵐キャンパス）  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：神戸  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福井県福井市  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福井県福井市  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Awaji Yumebutai International Conference Center, Hyogo, Japan  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：大阪  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：大阪  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Florence, Italy  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京豊島区  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京豊島区  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：名古屋  

researchmap

Language：Japanese   Presentation type：Poster presentation  

Venue：名古屋  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Niigata, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Niigata, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Niigata, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Niigata, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Niigata, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Niigata, Japan  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Turku, Finland  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Turku, Finland  

researchmap

Language：English   Presentation type：Poster presentation  

Venue：Turku, Finland  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都（国立京都国際会館）  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：吹田  

researchmap

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：吹田  

researchmap