Vibrational spectroscopic study and NBO analysis on bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) methane using DFT method.

In this work, we report a combined experimental and theoretical study on molecular structure, vibrational spectra, NBO analysis of bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) methane (BAMTM). The FT-Raman and FT-IR spectra of BAMTM were recorded in the solid phase. The molecular geometry, harmonic vibrational frequencies and bonding features of BAMTM in the ground state have been calculated by using density functional method (B3LYP) with standard 6-31G(d, p) basis set. Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Finally the theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed which show good agreement with recorded spectra.