一种线型具有ICT态共轭化合物的合成及光物理性质

A linear conjugative compound with intramolecular charge transfer (ICT) transition:synthesis and photophysical properties

运用Sonogashira偶联反应合成了一种具有分子内电荷转移(ICT)态的线型共轭化合物4,4'-(2,5-二溴-1,4-苯乙炔)4,4'-双(N,N-二甲基苯胺),研究了其在不同溶剂、质子和不同金属离子存在时紫外光谱及荧光光谱的变化。结果表明,该化合物中存在从供电子基团-N(CH3)2到吸电子基-Br的ICT光谱:随着溶剂极性的增加,其荧光光谱从正已烷中415nm红移到DMSO中525nm。对质子及一些过渡金属离子如Hg2+、Cr3+、Cu2+有明显响应,在乙腈溶液中,当化合物中滴加H+、Hg2+与Cr3+时,其荧光光谱表现为蓝移,而Cu2+的加入则使化合物的荧光淬灭。

A linear conjugative compound 4,4＇-（2,5-dibromo-1,4-phenylene）bis（ethyne-2,1-diyl）-bis（N,N-dimethylaniline） with intramolecular charge transfer（ICT） state was synthesized by Sonogashira cross-coupling reaction.Its UV-Visible and fluorescence spectral were investigated in different solvents and upon titration proton or metal cations.Our results indicated that the title compound underwent an intramolecular charge transfer from the electron-donor N,N-dimethylaniline to the electron-withdrawing group-Br.With the increase of the solvent polarity,the fluorescence spectra revealed a red shift from 415 nm in hexane to 525 nm in DMSO.In CH3CN solution,it seemed sensitive to proton and some transition metal cations,such as Hg^2＋,Cr^3＋ and Cu^2＋,with the fluorescence spectra a blue shift upon the addition of H^＋,Hg^2＋ or Cr^3＋,and a quenching effect on Cu^2＋.