Bulky Phenylalkyl Substitutions to Bisthienoisatins and Thienoisoindigos

• DOI: 10.1021/acs.cgd.0c00087
• Publication Date: 2020-04-08T16:10:50Z
• Authors: Dongho Yoo; Akihiro Kohara; Minoru Ashizawa; Tadashi Kawamoto; Hiroyasu Masunaga; Noboru Ohta; Hidetoshi Matsumoto; Takehiko Mori
• Keywords: Ambipolar diffusion; Electron Mobility; Crystal (programming language)

In order to investigate the effects of bulky substituents on crystal structures and packing modes, N-benzyl (Bn) N-2-phenylethyl (EtPh) are introduced in bisthienoisatin (BTI), thienoisoindigo (TIIG), dibenzothienoisoindigo (DBTII). These molecules maintain uniform stacking structures, though EtPh-BTI has a two-dimensional slipped-herringbone structure. The benzyl groups largely distorted from molecular core, thin films Bn-TIIG Bn-DBTII show poor quality due two kinds orientations. contrast, 2-phenylethyl-substituted enable suitable owing ethylene spacer relatively good thin-film qualities as well much improved transistor properties. BTI derivatives only electron transport, but other compounds exhibit ambipolar particular, EtPh-TIIG EtPh-DBTII maximum hole mobilities about 0.04–0.05 cm2 V–1 s–1 together with moderate mobilities.