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获得了2,5-二甲基-1,3,4-噻二唑(DMETD)在乙腈、甲醇和水中的紫外吸收光谱以及三种溶剂中不同激发波长下的共振拉曼光谱,并结合含时密度泛函TD-B3LYP/6-311++G(d,p)计算对DMETD的短时结构动力学进行了研究。通过固态的FT-Raman、FT-IR光谱和DFT计算指认了DMETD在溶剂中的共振拉曼光谱,并对DMETD共振拉曼光谱的强度模式进行了分析。结果表明DMETD在气相和溶剂中的跃迁主体都是π→π*。溶剂模型计算发现溶剂的极性对拉曼强度无影响。这样,DMETD在Franck-Condon区域活性振动模大致可以指认为7个基频v8,v12,v15,v17,v22,v23和v27以及它们的倍频和组合频,C=N和N-N伸缩振动占据了对拉曼强度的主要部分,说明S2激发态结构动力学也主要沿这两个坐标进行。
The UV absorption spectra of 2,5-dimethyl-1,3,4-thiadiazole (DMETD) in acetonitrile, methanol and water and the resonance Raman spectra at different excitation wavelengths in the three solvents were obtained, Time-density functional TD-B3LYP / 6-311 ++ G (d, p) calculations are used to investigate the short-time structural dynamics of DMETD. Resonance Raman spectra of DMETD in solvents were identified by solid-state FT-Raman, FT-IR and DFT calculations, and the intensity modes of DMETD resonance Raman spectra were analyzed. The results show that the main transitions of DMETD in gas and solvent are π → π *. Solvent model calculations revealed no effect of solvent polarity on Raman intensities. In this way, the active vibration modes of DMETD in the Franck-Condon region can be roughly identified as seven fundamental frequencies v8, v12, v15, v17, v22, v23 and v27 and their multiples and combination frequencies, with C = N and NN stretching vibrations The main part of the Raman intensity shows that the S2 excited state structure dynamics are also mainly along these two coordinates.