Synthesis, experimental and theoretical characterization, and field-effect transistor properties of a new class of dibenzothiophene derivatives: From linear to cyclic architectures
作者:Yali Qiao、Zhongming Wei、Chad Risko、Hong Li、Jean-Luc Brédas、Wei Xu、Daoben Zhu
DOI:10.1039/c1jm13962b
日期:——
We report the synthesis and characterization of a bis-dibenzothiophene cyclic dimer containing bis-ethylene linkages (DBT-CM) and of the corresponding mono-ethylene-linked ‘linear’ cis- and trans-isomers (ciscisciscis- and transtranstrans-DBT-LM, respectively). The varied molecular architectures lead to notable differences both in terms of the solid-state packing and the molecular electronic and optical properties. X-ray crystallography reveals that the cyclic architecture of DBT-CM leads to a more densely packed stacking configuration that imparts stronger intermolecular electronic coupling for both hole and electron transport amongst adjacent molecules, while characterization of the thin-film morphology and crystallinity uncovers important temperature-dependent properties of the films as a function of the molecular architecture. Moreover, the redox, electronic structure, and optical properties of DBT-CM vary distinctly from those of its linear counterparts. The intramolecular reorganization energies for hole and electron transport for DBT-CM are markedly smaller than the linear counterparts, while the dispersion for the highest valence band (and the intermolecular electronic coupling for hole transport) is the largest for the series. The more favorable molecular packing/morphology characteristics and charge-transport properties (within the Marcus framework) of DBT-CM manifest themselves in thin-film field-effect transistor studies, where a field-effect hole-carrier mobility 0.026 cm2 V−1 s−1 is measured, a value one-order-of-magnitude larger than either linear analog.
我们报告了含有双乙烯连接的双二苯并噻吩环状二聚体(DBT-CM)以及相应的单乙烯连接的 "线性 "顺式和反式异构体(分别为顺式和反式-DBT-LM)的合成和表征。不同的分子结构导致了固态填料以及分子电子和光学特性的显著差异。X 射线晶体学显示,DBT-CM 的环状结构导致了更密集的堆积构型,为相邻分子间的空穴和电子传输提供了更强的分子间电子耦合。此外,DBT-CM 的氧化还原、电子结构和光学特性也与其线性同类产品截然不同。DBT-CM 的空穴和电子传输的分子内重组能明显小于线性对应物,而最高价带的色散(以及空穴传输的分子间电子耦合)是该系列中最大的。DBT-CM 更为有利的分子填料/形态特征和电荷传输特性(在马库斯框架内)在薄膜场效应晶体管研究中得到了体现,在该研究中测得的场效应空穴-载流子迁移率为 0.026 cm2 V-1 s-1,比线性类似物大一个数量级。