Bitrialkylsilylethynyl thienoacenes: synthesis, molecular conformation and crystal packing, and their field-effect properties
作者:Weifeng Zhang、Ji Zhang、Xiangyang Chen、Zupan Mao、Xiaodong Xie、Liping Wang、Yi Liao、Gui Yu、Yunqi Liu、Daoben Zhu
DOI:10.1039/c3tc31421a
日期:——
In order to study the influence of molecular conformation on the packing mode of single crystals, four bitrialkylsilylethynyl thienoacenes, TIPS–ABT, TMS–ABT, TIPS–CABT and TMS–CABT, were synthesized and characterized. Since there are different conformations arising from the rotation of the isopropyl groups, two types of single crystals of the thienoacene TIPS–ABT were successfully grown, and the related quantum-chemical calculations predict that in theory they have significantly different hole mobilties (μh). For example, the μh of TIPS–ABT-1 is 1.74 cm2 V−1 s−1, a value nearly two hundred times larger than that of TIPS–ABT-2 (0.09 cm2 V−1 s−1), when the reorganization energy is obtained at the B3LYP/6-31+G(d) level. The results demonstrate the important influence of molecular conformation on the mode of crystal packing, and theoretically show the importance of organic semiconductor conformational control on the charge mobility. The thin film FET devices based on the four thienoacenes were prepared via the vacuum-deposit method. The TIPS–CABT-based devices afford hole mobilities of up to 0.012 cm2 V−1 s−1 with a current on–off ratio of 106.
为了研究分子构象对单晶堆积模式的影响,合成并表征了四种双三烷基甲硅烷基乙炔基噻吩并苯:TIPS-ABT、TMS-ABT、TIPS-CABT和TMS-CABT。由于异丙基的旋转产生不同的构象,成功生长了两种类型的噻吩并苯TIPS-ABT单晶,相关的量子化学计算预测理论上它们具有显着不同的空穴迁移率(μh)。例如,TIPS-ABT-1的μh为1.74 cm2 V−1 s−1,这个值比TIPS-ABT-2(0.09 cm2 V−1 s−1)大近200倍,当重组时能量在 B3LYP/6-31+G(d) 水平获得。结果证明了分子构象对晶体堆积模式的重要影响,并从理论上表明了有机半导体构象控制对电荷迁移率的重要性。采用真空沉积法制备了基于四种噻吩并苯的薄膜FET器件。基于 TIPS-CABT 的器件可提供高达 0.012 cm2 V−1 s−1 的空穴迁移率,电流开关比为 106。