3-烷基噻吩交替共聚物的合成及其电化学性质

Synthesis and Electrochemical Characteristics of 3-Alkylthiophene Copolymers

通过Heck偶联法合成了4种3-烷基噻吩交替共聚物:聚(2,4-二乙烯基-3-己基噻吩-1,3,4-二唑)(P3HT-OXD)、聚(2,4-二乙烯基-3-辛基噻吩-1,3,4-二唑)(P3OT-OXD)、聚(2,4-二乙烯基-3-己基噻吩-吡啶)(P3HT-Py)和聚(2,4-二乙烯基-3-辛基噻吩-吡啶)(P3OT-Py)。用NMR、GPC等测试技术对其结构进行了表征。采用循环伏安法、紫外-可见吸收光谱法研究了系列共聚物光电性能。结果表明,随噻吩环3位取代烷基碳链的增长,聚合物电离能(Ip)减小,带隙(Eg)也随之变窄。其中,P3OT-OXD的Eg比P3HT-OXD小0.11 eV,P3OT-Py的Eg比P3HT-Py小0.19 eV,在3-烷基噻吩聚合物主链上引入吸电子能力较强的二唑单元,可有效提高共聚物电子亲合能(Ea),对提高电子传输能力,改善电子与空穴注入平衡有积极作用。

A series of 3-alkylthiophene copolymers, poly [ （2,4-bisvinyl-3-hexyhhiophene-co-2,5-bisphenyt- 1,3,4-oxadiazole ] （P3HT-OXD）, poly [ （ 2, 4-bisvinyl-3-octylthiophene ） -co-2,5-bisphenyl-1, 3,4-Oxadiazole） ] （ P3OT-OXD ）, poly [ （ 2,4-bisvinyl-3-hexylthiophene ） -co-2,6-pyridine ] （ P3HT-Py ）, and poly [（2, 4-bisvinyl-3-octylthiophene ）-co-2, 6-pyridine ] （P3OT-Py） were synthesized by Heck Coupling approach. Their structures were characterized by NMR and gel permeation chromatography （GPC）. The photoelectric properties were investigated using cyclic vohammetry and UV-Vis spectroscopy. The results indicated that the ionization potential（ Ip） and hand gap（ Eg） of the copolymers were reduced with an increase of the length of the alkyl chain. The band gap of P3OT-OXD was 0. 11 eV lower than that of P3HT-OXD, and the band gap of P3OT-Py was 0. 19 eV lower than that of P3HT-Py. Electron affinity（ Ea） of polythiophene containing 1,3,4-oxadiazole in main chain was comparatively high, which will be avail to enhance electron-transporting effect and improve the balanced rates for electron and hole injection.