The preparation of trichloro(phenyl 2-pyridylmethyl sulphoxide)gold(III) and the kinetics and equilibria of its formation and subsequent reactions

Abstract

In the complex [Au(N–SO)Cl₃], formed between [AuCl₄]^– and phenyl 2-pyridylmethyl sulphoxide (N–SO), the ligand is bound only through the nitrogen and all attempts to induce chelation were unsuccessful. The kinetics of the forward and reverse reactions in methanol–water (95:5, v/v) at 25.0 °C are also consistent with the ligand acting as a substituted pyridine with a pK_a of 3.39 (water, 25 °C) and the same steric hindrance as 2-methylpyridine. The behaviour of gold(III) is compared to that of platinum(II).