5-巯基-1, 3, 4-噻二唑-2-硫酮微溶剂团簇的光谱和理论计算研究

微溶剂作用(即溶剂化过程)广泛存在于所有物理、 化学和生命过程中. 在液相化学反应体系中, 几乎是一切化学反应的基础. 通过傅里叶变换拉曼光谱(FT-Raman)并结合密度泛函理论(DFT), 表征了固态5-巯基- 1, 3, 4-噻二唑-2-硫酮(MTT)的结构, 并进一步确认了MTT在乙腈、 甲醇和水中微溶剂团簇的大小和氢键位点. 通过探究MTT在不同溶剂及pH条件下的紫外-可见吸收光谱(UV-Vis), 结合含时密度泛函理论(TD-DFT)计算, 揭示了溶剂和pH对MTT电子跃迁带的影响, 进一步解释了其光谱位移. 结合能量计算可以得出, MTT分别与1个乙腈、 2个甲醇和2个水分子形成MTT(CH₃CN), MTT(CH₃OH)₂ 和MTT(H₂O)₂团簇.

Spectroscopic and Theoretical Studies on 5-Mercapto-1，3，4-thiadiazole-2-thione Microsolvation Clusters

Microsolvation effect， namely solvation process， widely exists in all physical， chemical and life processes. In the liquid phase chemical reaction system， microsolvation effect is most fundamental for almost all chemical reactions. Crystalloid 5-mercapto-1，3，4-thiadiazole-2-thione（MTT） was characterized as thiol-thione monomer by Fourier transform Raman（FT-Raman） combined with density functional theoretical（DFT） calculation. Both the size and hydrogen bond sites of microsolvation clusters were confirmed in acetonitrile， methanol and water. UV-Vis absorption spectroscopic experiments revealed the effect of solvents and pH on the structures of MTT. Combined with density functional theory（DFT） calculations， the hydrogen bonding interactions between MTT and solvents contributed to the shifts of spectrum indicated. The MTT clusters in acetonitrile， methanol and water were preliminarily determined as MTT（CH₃CN）， MTT（CH₃OH）₂ and MTT（H₂O）₂ by optimizing the possible hydrogen-bonding cluster structures and calculating the total binding energy and average binding energy.