Torsional vibrations in some sulphur-nitrogen compounds studied by inelastic neutron scattering, infrared, and Raman spectroscopy

Abstract

The torsional modes in H₃N⁺SO₃^–, Na[O₃SNH₂], SO₂(NH₂)₂, and Ag₂[O₂SN₂H₂] have been assigned and the barrier heights and effective force constants calculated. The last two parameters increase with decreasing S–N bond length. The maximum splitting of the in- and out-of-phase NH₂ torsions in SO₂(NH₂), has been shown to be of the order of 16 cm^–1. From the spectroscopic data the salt Ag₂[O₂SN₂H₂] has been shown not to contain an NH₂ group, and this conclusion differs from that in an earlier publication. The SO₂ rocking and wagging modes are also observed because of their associated proton motion.