A Theoretical Study on the Vibrational Spectra and Thermodynamic Properties for the Derivatives of HNS with –CH3, –N3, and –NF2 Groups

Abstract

The derivatives of HNS are optimized to obtain their molecular geometries and electronic structures at the DFT-B3LYP/ 6-31G* level. Their IR spectra are obtained and assigned by vibrational analysis. Compared with the experimental results, all the calculated IR data are found to be reliable. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic properties are evaluated, which are respectively linearly related with the number of methyl, azido and difluoramino groups as well as the temperature, obviously showing good group additivity.