Thermodynamics of Complex Formation between Silver(I) and Mixed Phosphorus-Sulphur Ligands in Dimethyl Sulphoxide.

The thermodynamics of complex formation between silver(I) and the ligands Ph2PCH2SR (R = Me, Ph) and Ph2P(CH2)2SR (R = Et, Me, Ph) has been determined in dimethyl sulfoxide (dmso) at 25-degrees-C and in a medium of ionic strength 0.1 mol dm-3 by potentiometric and calorimetric measurements. Within the silver and ligand concentration ranges investigated, three mononuclear complexes have been determined. All the complexes are strongly enthalpy stabilized while the entropy changes are unfavourable. The ligands all behave as monodentate, coordinating the silver ion through the phoshorus atom. The influence of the length of the aliphatic chain between the donor atoms as well as of the nature of R on the stabilities of the complexes formed are discusse