Shih Feng-Yang, Choi Deokkyu, Wu Qin, Nam Chang-Yong, Grubbs Robert B
Chemistry department, Stony Brook University, Stony Brook, NY, 11794, USA.
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA.
Angew Chem Int Ed Engl. 2019 Jan 2;58(1):288-291. doi: 10.1002/anie.201809610. Epub 2018 Dec 4.
ipso-Arylative ring-opening polymerization of 2-bromo-8-aryl-8H-indeno[2,1-b]thiophen-8-ol monomers proceeds to M up to 9 kg mol with conversion of the monomer diarylcarbinol groups to pendent conjugated aroylphenyl side chains (2-benzoylphenyl or 2-(4-hexylbenzoyl)phenyl), which influence the optical and electronic properties of the resulting polythiophenes. Poly(3-(2-(4-hexylbenzoyl)phenyl)thiophene) was found to have lower frontier orbital energy levels (HOMO/LUMO=-5.9/-4.0 eV) than poly(3-hexylthiophene) owing to the electron-withdrawing ability of the aryl ketone side chains. The electron mobility (ca. 2×10 cm V s ) for poly(3-(2-(4-hexylbenzoyl)phenyl)thiophene) was found to be significantly higher than the hole mobility (ca. 8×10 cm V s ), which suggests such polymers are candidates for n-type organic semiconductors. Density functional theory calculations suggest that backbone distortion resulting from side-chain steric interactions could be a key factor influencing charge mobilities.
2-溴-8-芳基-8H-茚并[2,1-b]噻吩-8-醇单体的原位芳基化开环聚合反应可得到分子量高达9 kg mol的聚合物，单体二芳基甲醇基团转化为侧链共轭芳酰基苯基（2-苯甲酰基苯基或2-(4-己基苯甲酰基)苯基），这会影响所得聚噻吩的光学和电子性质。由于芳基酮侧链的吸电子能力，发现聚(3-(2-(4-己基苯甲酰基)苯基)噻吩)的前沿轨道能级（HOMO/LUMO = -5.9/-4.0 eV）比聚(3-己基噻吩)低。聚(3-(2-(4-己基苯甲酰基)苯基)噻吩)的电子迁移率（约2×10 cm V s ）显著高于空穴迁移率（约8×10 cm V s ），这表明此类聚合物是n型有机半导体的候选材料。密度泛函理论计算表明，侧链空间相互作用导致的主链扭曲可能是影响电荷迁移率的关键因素。
