He Mingqian, Li Jianfeng, Sorensen Michael L, Zhang Feixia, Hancock Robert R, Fong Hon Hang, Pozdin Vladimir A, Smilgies Detlef-M, Malliaras George G
Corning Incorporated, SP-FR-6, Corning, New York 14830, USA.
J Am Chem Soc. 2009 Aug 26;131(33):11930-8. doi: 10.1021/ja903895s.
A family of conjugated polymers with fused structures consisting of three to five thiophene rings and with the same alkyl side chains has been synthesized as a means to understand structure-property relationships. All three polymers showed well-extended conjugation through the polymer backbone. Ionization potentials (IP) ranged from 5.15 to 5.21 eV; these large values are indicative of their excellent oxidative stability. X-ray diffraction and AFM studies suggest that the polymer with the even number of fused thiophene rings forms a tight crystalline structure due to its tilted side chain arrangement. On the other hand, the polymers with the odd number of fused thiophene rings packed more loosely. Characterization in a field-effect transistor configuration showed that the mobility of the polymer with the even number of rings is 1 order of magnitude higher than its odd-numbered counterparts. Through this structure-property study, we demonstrate that proper design of the molecules and properly arranged side chain positions on the polymer backbone can greatly enhance polymer electronic properties.
已合成了一族具有稠合结构的共轭聚合物，其由三至五个噻吩环组成且具有相同的烷基侧链，以此作为理解结构-性能关系的一种手段。所有这三种聚合物通过聚合物主链都表现出良好的共轭延伸。电离势（IP）范围为5.15至5.21电子伏特；这些较大的值表明它们具有优异的氧化稳定性。X射线衍射和原子力显微镜研究表明，具有偶数个稠合噻吩环的聚合物由于其倾斜的侧链排列而形成紧密的晶体结构。另一方面，具有奇数个稠合噻吩环的聚合物堆积得更为松散。在场效应晶体管配置中的表征表明，具有偶数个环的聚合物的迁移率比其具有奇数个环的对应物高一个数量级。通过这项结构-性能研究，我们证明了分子的合理设计以及聚合物主链上侧链位置的合理排列可以极大地提高聚合物的电子性能。
