Normal coordinate analysis of the sulphamate ion

Abstract A normal coordinate analysis of the sulphamate ion has been carried out using the Urey—Bradley force field and the laser Raman frequencies of a single crystal of potassium sulphamate. Treating the structure as a whole ( C s symmetry), the force constants have been refined. The results are consistent with an increase in double-bond character of the NS bond and the presence of hydrogen bonding in the crystal. Comparison of the force constants with those of sulphamic acid confirms the shortening of the NS bond in KNH 2 SO 3 .