Vibrational Spectra and Structure of Sulphonium Nitroimides

During a physico-chemical study of three new types of sulphonium nitroimides by vibrational spectroscopy and X-ray analysis the structural parameters of Me₂SNNO₂, Me₂S(O)NNO₂ and Me₂S(NNO₂)₂ molecules were determined; variations in the stretching vibrations of the nitro group in the spectra of sulphonic nitroimides, nitroamines and their salts were found to result from large differences in the force constants, especially the nondiagonal, of these molecules.