Substitution effect on molecular packing and transistor performance of indolo[3,2-b]carbazole derivatives
作者:Guangyao Zhao、Huanli Dong、Huaping Zhao、Lang Jiang、Xiaotao Zhang、Jiahui Tan、Qing Meng、Wenping Hu
DOI:10.1039/c1jm14891e
日期:——
In this manuscript, two chloro-substituted derivatives of indolo[3,2-b]carbazole (ICZ), 2,8-dichloro-indolo[3,2-b]carbazole (CICZ) and 2,8-dichloro-5,11-dihexyl-indolo[3,2-b]carbazole (CHICZ) were designed and synthesized. The only difference between CICZ and CHICZ is at the N-5 and N-11 positions with or without long alkyl side chains. Interestingly, CICZ and CHICZ exhibited similar thermal, optical, and electrochemical properties, while their molecular packing motifs in solid state and corresponding charge transport properties were significantly different. The alkyl chains at N-5 and N-11 positions were proved not only enhancing the solubility and self-organization of the compounds but also shifting the molecular packing from herringbone (CICZ) to one-dimensional π–π stacking (CHICZ). Moreover, nearly no field-effect performance was observed for CICZ, while the mobility of CHICZ was as high as 0.14 cm2 V−1 s−1 for its thin films and 0.5 cm2 V−1 s−1 for its single crystals. These results confirmed that the chemical substitutions are a powerful molecular design tool to tune the molecular packing motifs of organic semiconductors and their corresponding electronic properties.
在这份手稿中,设计并合成了两种吲哚并[3,2-b]咔唑(ICZ)的氯代衍生物:2,8-二氯-吲哚并[3,2-b]咔唑(CICZ)和2,8-二氯-5,11-二己基-吲哚并[3,2-b]咔唑(CHICZ)。CICZ和CHICZ的唯一区别在于N-5和N-11位置是否有长烷基侧链。有趣的是,CICZ和CHICZ表现出相似的热学、光学和电化学性质,而它们的固态分子堆积图案和相应的电荷传输性质却大不相同。事实证明,N-5和N-11位置的烷基链不仅增强了化合物的溶解度和自组织性,还使分子堆积从人字形(CICZ)转变为一维π-π堆积(CHICZ)。此外,CICZ几乎没有观察到场效应性能,而CHICZ的薄膜迁移率高达0.14 cm2 V-1 s-1,单晶迁移率高达0.5 cm2 V-1 s-1。这些结果证实,化学取代是一种强大的分子设计工具,可以调节有机半导体的分子堆积图案及其相应的电子性质。