Linear Ladder-Type π-Conjugated Polymers Composed of Fused Thiophene Ring Systems
作者:Kenichi Oyaizu、Tomokazu Iwasaki、Yoshiaki Tsukahara、Eishun Tsuchida
DOI:10.1021/ma030520p
日期:2004.2.1
The geometric and band electronic structure of the ladder-type polymer were calculated and analyzed at the PM5 level of theory. The fused ring structure imposes strong quinonoid-type character to the originally benzenoid polyene backbone, which destabilizes the HOMO and stabilizes the LUMO and thus reduces the band gap. The shift of absorption and emission maxima to longer wavelengths responding to
合成并表征了一种新型的并苯碳-硫(C 2 S)类似物。聚合物由非简并的反式-顺式聚乙炔骨架,其中所有氢原子均被硫原子取代,形成噻吩环,该环稠合成线性交叉共轭梯形结构。阶梯型聚合物的新开发合成路线是基于三氟甲磺酸中由3-(烷烃-1-亚磺酰基)噻吩-2,5-二基单元组成的预聚物的分子内缩合。在理论的PM5水平上计算并分析了梯型聚合物的几何结构和能带电子结构。稠合的环结构对最初的苯类多烯骨架施加强的醌类特征,这使HOMO不稳定并稳定了LUMO,从而减小了带隙。与聚噻吩相比,吸收和发射最大值向更长波长的移动响应的π-π*跃迁能量更低,而电化学p和n掺杂电势之间的较小间隙与带隙的减小相一致。对于短链和中链长度,计算了分离的低聚物在其中性,单氧化和双氧化态下的微观结构。从小阳离子或阳离子的性质到足够长的链上孤立的极化或双极化缺陷的性质,对聚合行为的各种能量和结构方面进行了监测和讨论。通过采用合适的边界