两种非对称芳基二噻吩并[2,3-b:3′,2′-d]噻吩的合成与光谱特性

Synthesis and spectroscopic properties of two asymmetric aryl dithieno[2,3-b:3′,2′-d]thiophenes

合成了两种非对称芳基取代的并三噻吩化合物.以2-溴-5-三甲基硅-二噻吩并[2,3-b:3′,2′-d]噻吩为原料,经脱除四甲基硅烷(TMS)和Suzuki偶联两步反应制备了2-噻吩基二噻吩并[2,3-b:3′,2′-d]噻吩,总产率为67.4%;以2-苯基二噻吩并[2,3-b:3′,2′-d]噻吩为原料,经N-溴代琥珀酰亚胺(简称NBS)溴代和Suzuki偶联两步反应制备了2-苯-5-噻吩基二噻吩并[2,3-b:3′,2′-d]噻吩,总产率为27.8%.产物经核磁共振谱(1H NMR,13C NMR)和质谱(MS)分析确认;利用紫外-可见分光光度法(UV-Vis)分析了合成产物的荧光特性.结果表明,由于苯基的存在,2-噻吩-5-苯基二噻吩并[2,3-b:3′,2′-d]噻吩分子的共轭体系增大,导致其吸收峰红移、发光能力减弱.

Two asymmetric aryl dithieno[2,3-b：3′,2′-d]thiophenes were synthesized.Namely,2-（thiophen-3-yl）dithieno[2,3-b：3′,2′-d]thiophene was synthesized in a total yield of 67.4% with 2-bromo-5-trimethylsilanyl-dithieno[2,3-b：3′,2′-d]-thiophene as the starting material,via removal of tetramethylsilane（TMS） group and Suzuki reaction.Then another asymmetric aryl dithieno[2,3-b：3′,2′-d]thiophene,2-phenyl-5-（thiophen-3-yl）dithieno[2,3-b：3′,2′-d]thiophene was synthesized in a total yield of 27.8% with 2-phenyldithieno[2,3-b：3′,2′-d]thiophene as raw material,via bromination by N-bromosuccinimide（NBS） combined with Suzuki reaction.Two title compounds were characterized by means of magnetic resonance spectroscopy and mass spectrometry.Their fluorescent characteristics were evaluated by means of ultraviolet-visible light（UV-Vis） spectrophotometry.Results indicate that 2-phenyl-5-（thiophen-3-yl）dithieno-[2,3-b：3′,2′-d]thiophene bearing phenyl group has a stronger conjugation system,showing red-shifted absorption spectra and decreased fluorescent intensity.