Nucleation Control-Triggering Cocrystal Polymorphism of Charge-Transfer Complexes Differing in Physical and Electronic Properties

Binary charge-transfer complex polymorphs composed of perylene and 4,8-bis­(dicyanomethylene)-4,8-dihydrobenzo-[1,2-b:4,5-b′]-dithiophene (DTTCNQ) were synthesized separately via a simple artificial nucleation-tailoring method, in both macroscopic and microscopic cocrystal engineering manners. The two polymorphs were testified to be independently thermosalient in the solid state, and the specific self-assembly derived from homogeneous or heterogeneous nucleation by assistance of governable thermodynamic/kinetic drive, leading to a change in the ordered p–n stacking structure. The as-prepared polymorphic microcrystals afforded a significantly varied (opto)­electronic property: high n-type transporting and good photoresponsivity for β-complex, and ambipolar transporting with ignorable photoresponsivity for α-complex, attributing to the different charge-transfer and supramolecular alignment. This work provides us a new route to the exploitation of donor–acceptor complex family, making it possible to develop functional materials and devices based on variable supramolecular binary structures.以苝（perylene）与4,8-双(二氰亚甲基)-4,8-二氢苯并[1,2-b:4,5-b′]-二噻吩（DTTCNQ）为构筑单元的二元电荷转移复合物（charge-transfer complex）多晶型物，可通过简便的人工成核调控策略，分别采用宏观与微观共晶工程手段合成得到。经表征验证，这两种多晶型物在固态下均表现出独立的热致形变特性；通过可控热力学/动力学驱动力调控均相成核与异相成核过程，可得到特定的自组装结构，进而改变有序p-n堆叠模式。所制备的多晶型微晶展现出显著差异的光电子（optoelectronic）学性能：β型复合物具备优异的n型传输特性与良好的光响应性，而α型复合物则表现为双极性传输且光响应性可忽略不计，这一性能差异源于二者不同的电荷转移特性与超分子排列方式。本研究为给体-受体复合物家族的开发提供了全新途径，有望基于可变超分子二元结构构建功能材料与器件。