Acta Chim. Sinica ›› 2016, Vol. 74 ›› Issue (4): 335-339.DOI: 10.6023/A15120782 Previous Articles     Next Articles



杨宁a,b, 乔小兰b, 房忍忍b, 陶竞炜b, 郝健a, 李洪祥b   

  1. a. 上海大学化学系 上海 200444;
    b. 中国科学院上海有机化学研究所 上海 200032
  • 投稿日期:2015-12-18 发布日期:2016-03-03
  • 通讯作者: 郝健, 李洪祥;
  • 基金资助:

    项目受国家自然科学基金(Nos. 51273212, 51303201)资助.

Syntheses and Properties of Five-Ring Fused Azo- and Thio-Aromatic Compounds Containing Imide Substituent

Yang Ninga,b, Qiao Xiaolanb, Fang Renrenb, Tao Jingweib, Hao Jiana, Li Hongxiangb   

  1. a Department of Chemistry, Shanghai University, Shanghai 200444;
    b Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032
  • Received:2015-12-18 Published:2016-03-03
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 51273212, 51303201).

Five-ring fused azo-and thio-aromatic compounds 1 and 2 containing imide substituent were designed and synthesized. 3,4-Dibromo-1-(2-ethylhexyl)-1H-pyrrole-2,5-dione reacted with lithium indyl and benzothiophene-3-boronic acid respectively, affording intermediates 3 and 4. Compound 3 was intramolecular cyclized in the presence of PdCl2 to give target compound 1. And compound 2 was prepared through intramolecular cyclization of intermediate 4 by means of photochemical ringclosure reaction and oxidation. The physicochemical properties of compounds 1 and 2 were thoroughly investigated with TGA, UV-vis absorption spectra and cyclic voltammetry. Experimental results showed the introduction of imide substituent not only increased the solubility of compounds 1 and 2, but also decreased their energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). The HOMO/LUMO energy levels of compounds 1 and 2 are -5.58/-2.25 eV and -6.04/-3.51 eV respectively. Single crystals of compound 1 were grown through solvent evaporation method in the mixture of dichloromethane and petroleum ether. Single crystal structure revealed compound 1 has a planar conjugated core and forms dimmer in the crystal. Strong π-π intermolecular interactions exist in the dimmer, and hydrogen bonds (NH…O=C) are observed among dimmers. The charge carrier mobilities of compounds 1 and 2 were investigated through thin film transistors. The transistors were fabricated with top-contact/bottom-gate device configurations. And thin films were deposited in vacuum on octadecyltrichlorosilane (OTS)-modified Si/SiO2 substrates. Transistors performance of compound 2 displays obvious p-type performance with a mobility of 2.75×10-3 cm2·V-1·s-1. However, compound 1 exhibited no organic field-effect transistor (OFET) behavior. In order to understand the different device performances of compounds 1 and 2, their thin films were investigated by atomic force microscopy (AFM) and X-ray diffraction (XRD). AFM images showed that compound 1 formed continuous thin film with small size of microstructures, the existence of grain boundaries hindered the transport of charge carriers in the film. XRD curves revealed that compound 2 formed crystalline thin films. Though the continuity of 2 films was worse than that of 1, the larger size of microstructures and the crystalline property of the films facilitated the transport of charge carriers.

Key words: organic semiconductors, five-ring fused aromatic molecules, organic thin film transistors