Synthesis and properties of a benzo[1,2-b:4,5-b′]dithiophene core π-system that bears alkyl, alkylthio and alkoxy groups at 3,7-positions
作者:Shinya Ota、Sojiro Minami、Koji Hirano、Tetsuya Satoh、Yutaka Ie、Shu Seki、Yoshio Aso、Masahiro Miura
DOI:10.1039/c3ra41822g
日期:——
A synthetic sequence was developed to provide 3,7-didodecylbenzo[1,2-b:4,5-bâ²]dithiophene and its dialkylthio and dialkoxy analogues as planar and soluble building-blocks for constructing benzodithiophene-based Ï-systems. The benzodithiophenes were also transformed to the corresponding 2,6-di(5-phenyl-2-thienyl)-capped derivatives as the representative oligomers. Their absorption and emission spectra as well as CV data showed that the HOMOâLUMO energy gaps of the dialkylthio and dialkoxy derivatives are smaller than that of the dialkyl one, which is attributable to the lower ELUMO as well as EHOMO energies of the dialkylthio analogue and the higher EHOMO energy of the dialkoxy analogue, respectively. The intra- and intermolecular charge-carrier mobilities were then estimated by the flash-photolysis time-resolved microwave conductivity (FP-TRMC) method and solution-processed top contact FET performance. The TRMC method showed similar high intrinsic hole mobilities (0.16â0.24 cm2 Vâ1 sâ1) irrespective of the substituents, whereas the dialkyl derivative especially displayed a good field-effect mobility of 0.023 cm2 Vâ1 sâ1.
开发了一种合成序列,提供3,7-二十二烷基苯并[1,2-b:4,5-b']二噻吩及其二烷硫基和二烷氧基类似物,作为构建苯并二噻吩基π系统的平面和可溶性构建块。苯并二噻吩也被转化为相应的2,6-二(5-苯基-2-噻吩基)封端衍生物作为代表性寡聚物。它们的吸收和发射光谱以及CV数据显示,二烷硫基和二烷氧基衍生物的HOMO-LUMO能隙小于二烷基衍生物,这可归因于二烷硫基类似物的较低ELUMO和EHOMO能量,以及二烷氧基类似物的较高EHOMO能量。然后通过闪光光解时间分辨微波电导(FP-TRMC)方法和溶液处理顶部接触FET性能估算了分子内和分子间的载流子迁移率。TRMC方法显示,无论取代基如何,固有空穴迁移率相似且高(0.16-0.24 cm² V⁻¹ s⁻¹),而二烷基衍生物尤其显示出良好的场效应迁移率0.023 cm² V⁻¹ s⁻¹。