Interaction of gold(I) with thiosulfate–sulfite mixed ligand systems

The View the MathML sourceAu(I)–SO32-–S2O32- system was studied at 25 °C and at I = 0.1 M NaClO4 using hydrodynamic voltammetry, gold potentiometry, UV–Vis spectrophotometry and Raman spectroscopy. The presence of two mixed-ligand species, Au(S2O3)(SO3)3− and View the MathML sourceAu(S2O3)(SO3)25-, was detected from the Raman experiments and supported by the gold potentiometric experiments. The stepwise formation constant, log K 11r, for the reaction View the MathML sourceAu(S2O3)23-+rSO32-⇔Au(S2O3)(SO3)r-(2r+1)+S2O32- was found to be 1.1 (r = 1) and 4.8 (r = 2) from the hydrodynamic voltammetric experiments