2-氨基-5-甲硫基-1,3,4-噻二唑的FT-IR,FT-Raman和共振拉曼光谱指认

The Identification of 2-Amino-5-(Methylthio)-1,3,4-Thiadiazole Through FT-IR,FT-Raman and Resonance Raman Spectra

利用共振拉曼光谱技术以及密度泛函理论(DFT)计算对2-氨基-5-甲硫基-1,3,4-噻二唑(5-AMTT)在Franck-Condon区域的光诱导激发态短时动力学进行了研究。通过实验获得了5-AMTT固体的FT-IR和FTRaman光谱,并结合量子化学计算确认了5-AMTT的稳定构型。获得了5-AMTT在乙腈、甲醇和水溶剂中309.1nm激发波长下的共振拉曼光谱图。共振拉曼光谱可以被指认为9个Frank-Condon活性振动模的基频、倍频和它们的组合频,其中5-AMTT环上C5N4的伸缩振动、CH3上C—H的振动以及NH2的振动的基频、倍频和组合频占据了其主要吸收带共振拉曼光谱强度的绝大部分,表明5-AMTT激发态结构动力学主要沿着这些反应坐标展开。

In this paper,the short-time dynamics of 2-Amino-5-（methylthio）-1,3,4-thiadiazole（5-AMTT）in photo-induced excited state have been investigated in the Franck-Condon region by resonance Raman spectra and density functional theoretical（DFT）calculation.FT-IR and FT-Raman spectra of 5-AMTT solid are gained through experiments,and the stable form of 5-AMTT was also calculated and confirmed in combination of quantum chemical calculations.Meanwhile,resonance Raman spectra of 5-AMTT at 309.1nm excitation wavelength in acetonitrile,methanol and water was gained.Resonance Raman spectrum can be assigned to fundamental frequency and doubling frequency of 9Franck-Condon active vibration modes as well as their combined frequency,where fundamental frequency,frequency doubling and combined frequency of C5N4stretching vibration on 5-AMTT,C—H vibration on CH3 and NH2vibration occupy the vast majority of main absorption band-resonance Raman spectrum intensity.This indicates structural dynamics of 5-AMTT in excited state mainly spreads along these reaction coordinates.