Vibrational spectra and force constants of heptasulfur imide

Abstract

Raman, infrared, and far-infrared spectra of solid and dissolved S7NH, STND, S716NH, and S715ND have been recorded. All fundamental frequencies of heptasulfur imide have been observed and assigned in accordance with the molecular symmetry C,. A normal-coordinate treatment was carried out using a modified Urey-Bradley force field with 16 independent force constants. Good agreement between observed and calculated frequencies was obtained and both Urey-Bradley and valence force constants are reported.