Alternating Terpolymers Based on Tunable Bi-donors with Manipulating Energy Levels and Molecular Geometry

作     者：CHEN Zhenzhu YANG Jia WU Feiyan CHEN Lie CHEN Yiwang 

作者机构：College of Chemistry Institute of Polymers Nanchang University Nanchang 330031 P. R. China Jiangxi Provincial Key Laboratory of New Energy Chemistry Nanchang University Nanchang 330031 P. R. China 

出 版 物：《Chemical Research in Chinese Universities》 (高等学校化学研究（英文版）)

年 卷 期：2017年第33卷第2期

页      面：305-311页

核心收录：

学科分类：07[理学] 

基　　金：Supported by the National Science Fund for Distinguished Young Scholars, China 国家自然科学基金 江西省自然科学基金 

主　　题：Terpolymer Electron-donating Energy level Molecular geometry 

摘      要：Three novel regular acceptor-donorl-acceptor-donor2（A-D1-A-D2） terpolymers were prepared via em-bedding a second donor（D2） unit into the traditional D-A backbone to manipulate the energy levels and moleculargeometry with no complex synthesis or solubility loss. In these A-D1-A-D2 terpolymers, benzodithiophene（BDT, D1）and diketopyrrolopyrrole（DPP, A） were selected as the basic skeleton, and the dithienopyrrole（DTPy）, carbazole（CZ）and fluorine（FL） units with different electron donating ability were chosen as the second donor trait（D2）. The HOMOenergy levels can be effectively modulated by only varying D2 unit because of the push-pull interaction between do-nor and acceptor units. Versus the D-A bipolymer PDPP-BDT, incorporation of the D2 unit into the copolymers candistinctly lower the highest occupied molecular orbital（HOMO） levels to -5.47 eV for PDDPP-BDT-DTPy, -5.38 eVfor PDDPP-BDT-CZ and -5.23 eV for PDDPP-BDT-FL, which shows the strong dependence on electron-donatingability. Density functional theory（DFT） simulation and X-ray diffraction（XRD） measurements also reveal the effectof the D2 units on the molecular geometry of the terpolymers and their molecular packing. Notably, aPDDPP-BDT-DTPy combined with a thiophene ring and forked tail pendant away from the backbone had less back-bone torsion and more compact packing than the other two counterparts. These results demonstrate that embedding asecond donor（D2） unit into the backbone to construct an A-D1-A-D2 structure can be an effective and direct strategyto manipulate the energy levels and molecular geometry and develop organic semiconducting materials.