Experimental and theoretical study on 4-phenyl-3-[(1,2,4-triazol-1-yl)methyl]-triazole-5-thione

The title compound, 4-phenyl-3-[(1,2,4-triazol-l-yl)methyl]-triazole-5-throne, was synthesized and characterized by elemental analysis, IR and electronic spectra. Density functional theory calculations of the structure, natural bond orbital and thermodynamic functions of the title compound were performed at B3LYP/6-311G** level of theory. Vibrational frequencies were predicted, assigned, compared with the experimental values, and they are supported each other. Electronic absorption spectra were calculated by the time-dependent density functional theory (TD-DFT), which indicates that the two absorption bands are mainly derived from the contribution of bands pi -> pi(*). The calculation of the second order optical nonlinearity was carried out with PM3 semi-empirical method that resulted in the molecular hyperpolarizability equal to 4.397 x 10(-30) esu.