Studies of the protonation equilibria of sulphamates using 13C and 1H nuclear magnetic resonance spectroscopic, potentiometric, and conductimetric methods

Abstract

pK_a Values are determined for the ionization R[graphic omitted]H₂SO₃⇌ RNHSO₃^–+ H⁺ for sulphamates with R = Buⁿ, Prⁿ Bu⁸, and cyclohexyl using ¹³C and ¹H n.m.r. spectroscopic, potentiometric, and conductimetric methods. These compounds have pK_a values in the range 1–1.9 and they are thus less acidic than sulphamic acid. Intramolecular standards were used in the n.m.r. measurements. The similarity in the pK_a values determined by the two n.m.r. methods suggests that solvation effects are small.