The electron deficiency and trans-planar conformation of bithiazole is potentially beneficial for the electron-transport performance of organic semiconductors. However, the incorporation of bithiazole into polymers through a facile synthetic strategy remains a challenge. Herein, 2,2′-bithiazole was synthesized in one step and copolymerized with dithienyldiketopyrrolopyrrole to afford poly(dithienyldiketopyrrolopyrrole-bithiazole), PDBTz. PDBTz exhibited electron mobility reaching 0.3 cm2 V–1 s–1 in organic field-effect transistor (OFET) configuration; this contrasts with a recently discussed isoelectronic conjugated polymer comprising an electron-rich bithiophene and dithienyldiketopyrrolopyrrole, which displays merely hole-transport characteristics. This inversion of charge-carrier transport characteristics confirms the significant potential for bithiazole in the development of electron-transport semiconducting materials. Branched 5-decylheptacyl side chains were incorporated into PDBTz to enhance polymer solubility, particularly in nonhalogenated, more environmentally compatible solvents. PDBTz cast from a range of nonhalogenated solvents exhibited film morphologies and field-effect electron mobility similar to those cast from halogenated solvents.
联
噻唑的电子缺陷和跨平面构象可能有利于有机半导体的电子传输性能。然而,通过简便的合成策略将双
噻唑掺入聚合物中仍然是一项挑战。本文一步合成了 2,2′-双
噻唑,并将其与二
噻吩基二酮
吡咯共聚,得到了聚(二
噻吩基二酮
吡咯-双
噻唑),即 PDBTz。PDBTz 在有机场效应晶体管(OFET)构型中的电子迁移率达到 0.3 cm2 V-1 s-1;这与最近讨论的一种等电子共轭聚合物形成了鲜明对比,这种聚合物由富含电子的
噻吩和二
噻吩基二
吡咯并
吡咯组成,只具有空穴传输特性。这种电荷载流子传输特性的反转证实了双
噻唑在开发电子传输半导体材料方面的巨大潜力。在 PDBTz 中加入了支化的 5-癸基庚酰侧链,以提高聚合物的溶解度,尤其是在非卤化、更环保的溶剂中的溶解度。从一系列非卤化溶剂中浇铸的 PDBTz 显示出与从卤化溶剂中浇铸的 PDBTz 相似的薄膜形态和场效应电子迁移率。