作者:Minghan Cai、Chongguang Zhao、Dongdong Zhang、Xiaozeng Song、Lian Duan
DOI:10.1007/s11426-018-9434-6
日期:2019.6
Promoting electron mobility is the key to designing high performance electron transport materials (ETMs). Formation of intermolecular interaction can be helpful to enhance their electron mobilities as a result of more ordered molecular stacking. Here, to reveal the inherent influence of intermolecular π-π stacking on the electron mobilities, we designed two ETMs, namely, 2,4-diphenyl-6-[3-(2-triphenylenyl)phenyl]-1,3,5-triazine (TPTRZ) and 2,4-diphenyl-6-[4′-(2-triphenylenyl)[1,1′-biphenyl]-3-yl]-1,3,5-triazine (TPPTRZ). Thermal, photophysical and electrochemical measurement results indicate they are good ETM candidates. Additionally, TPTRZ and TPPTRZ exhibit high electron mobilities of 3.60×10−5 and 3.58×10−5 cm2 V−1 s−1, respectively, at an electric field of 7×105 V cm−1. By taking X-ray single crystal structure, theoretical calculation and time of flight (TOF) results into consideration, it is revealed that strong intermolecular π-π stacking induced by planar triphenylene and triphenyltriazine units renders TPTRZ and TPPTRZ small energetic and positional disorder parameters, and results in their high electron mobilities thereby. By further enhancing intermolecular π-π stacking, ETMs with even higher electron mobilities can thus be anticipated.
提高电子迁移率是设计高性能电子传输材料(ETMs)的关键。分子间相互作用的形成有助于通过更有序的分子堆积提高电子迁移率。在此,为了揭示分子间π-π堆积对电子迁移率的内在影响,我们设计了两种 ETM,即 2,4-二苯基-6-[3-(2-三亚苯基)苯基]-1,3,5-三嗪(TPTRZ)和 2,4-二苯基-6-[4′-(2-三亚苯基)[1,1′-联苯]-3-基]-1,3,5-三嗪(TPPTRZ)。热学、光物理和电化学测量结果表明,它们是良好的 ETM 候选物质。此外,在 7×105 V cm-1 的电场下,TPTRZ 和 TPPTRZ 的电子迁移率分别高达 3.60×10-5 和 3.58×10-5 cm2 V-1 s-1。通过对 X 射线单晶结构、理论计算和飞行时间(TOF)结果进行分析,发现平面三苯基和三苯基三嗪单元引起的强分子间π-π堆叠使 TPTRZ 和 TPPTRZ 的能量和位置紊乱参数较小,从而导致了它们的高电子迁移率。通过进一步加强分子间的π-π堆叠,可以预见 ETM 具有更高的电子迁移率。