二芳基乙烯类光致变色化合物的合成及其光电性质研究

在氮气及-78℃条件下,合成了两种二芳基乙烯类光致变色化合物1,2-双(2-甲基-5-(4-N,N-二甲氨基苯基)噻吩-3-基)全氟环戊烯(Ⅰa)和1,2-双(2-甲基-5-萘基噻吩-3-基)全氟环戊烯(Ⅱa),通过紫外-可见吸收光谱、荧光光谱、循环伏安法对其光谱特性和电化学性质进行了初步研究。在254nm紫外光照射下,Ⅰa和Ⅱa的氯仿溶液均由无色变为蓝色,最大吸收峰分别为620和570nm,在适当波长可见光照射下,均从有色态返回到无色态。通过UV-Vis光谱考察了这两种二芳基乙烯类化合物在溶液中的光致变色反应的动力学特征,实验结果表明,二芳基乙烯类光致变色化合物的闭环反应属于零级反应,开环反应为一级。电化学研究表明,在溶液中,Ⅰa和Ⅱa可发生不可逆的阳极氧化反应。

Synthesis and Optoelectronic Properties of Two Photochromic Dithienylethene Compounds

Two photochromic dithienylethene compounds,1,2-bis[2-methyl-5(p-N,N-dimethylamino- phenyl)-3-thienyl]perfluorocyclopentene(Ⅰa) and 1,2-bis(2-methyl-5-naphthalene-3-thienyl)perfluorocyclopentene(Ⅱa) were synthesized,and their optoelectronic properties and electrochemical properties were systematically investigated.These dithienylethenes show good photochromic behavior both in solution and in PMMA amorphous film.All of them exhibit relative strong fluorescence.Upon irradiation with 254 nm UV light,the colorless CHCl-3 solution of compound Ⅰa and Ⅱa turned blue,in which the absorption maxima were observed at 620 and 570 nm respectively.The colored solution returned to a colorless one on irradiation with visible light (λ>500 nm).Their photochromic cyclization reaction and cycloreversion reaction were deterimined to be zeroth and first order reactions,respectively.The irreversible anodic oxidation of Ⅰa and Ⅱa were occurred by performing cyclic voltammetry tests.