Synthesis of novel optically active poly(thiophenyleneethynylenephenylene)s. Effects of chirality competition and cooperation at the side chains on higher order structures

被引：6

作者：

Miyagi, Yu ^{[1
]}

Otaki, Yoshinori ^{[1
]}

Takahashi, Yuki ^{[1
]}

Sanda, Fumio ^{[1
]}

机构：

[1] Kansai Univ, Dept Chem & Mat Engn, Fac Chem Mat & Bioengn, 3-3-35 Yamate Cho, Suita, Osaka 5648680, Japan

来源：

POLYMER | 2017年 / 130卷

关键词：

Chirality competition; Chirality cooperation; Higher order structure; Optically active; Poly(thiophenyleneethynylenephenylene); CHIROPTICAL PROPERTIES; DENSITY FUNCTIONALS; AZOBENZENE MOIETIES; CONJUGATED POLYMERS; HELICAL SENSE; POLY(N-PROPARGYLAMIDES); POLYMERIZATION; TEMPERATURE; SOLVENT; CD;

D O I：

10.1016/j.polymer.2017.09.014

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Novel poly(thiophenyleneethynylenephenylene)s having optically inactive/active amide groups were synthesized by the Sonoghashira-Hagihara coupling polymerization of 3-substituted 2,5-dibromothiophene 1 with 1-substituted 3,5-diethynylbenzenes 2N, 2R, 2S derived from glycine and D-/L-alanines. Poly(1-2S) exhibited an intense Cotton effect based on negative exciton chirality at 405 and 366 nm. On the other hand, poly(1-2N) exhibited a Cotton effect similar to that of poly(1-2S) but weaker, and poly(1-2R) exhibited a weak Cotton effect based on positive exciton chirality. The chiral secondary structures of the polymers were dependent on chirality cooperation and chirality competition of the side chains. The trend of the circular dichroism (CD) signs and intensities of the polymers can be explained by the concepts of "chiral cooperation" and "chiral competition" between the optically active thiophene unit and optically inactive/ active phenylene unit. These polymers formed aggregate structures with increasing MeOH content of CHCl3/MeOH mixed solvents, with accompanying decrease of the UV-vis absorptions and photoluminescence (PL) intensities. (C) 2017 Elsevier Ltd. All rights reserved.

引用

页码：250 / 257

页数：8

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[1] π-organogels of self-assembled p-phenylenevinylenes:: Soft materials with distinct size, shape, and functions [J].