Preferential salvation in N-methylthiourea

Abstract

The chemical shifts of the NH and NH2 protons in N-methylthiourea dissolved in binary mixed solvents show a dependence on the solvent molar fractions typical of preferential solvation processes. The degree of preferential salvation determined from the NH resonance depends mainly on the donor properties of the components of the mixture; however, those obtained from the NH2 protons show also the influence of the solvent acceptor properties. These results, as well as some deviations from the general behaviour, are discussed considering the different degree of the electron delocalization along both branches of the thiourea