Determination of the composition and the stability constants of complexes of silver(I) with some sulphur containing pyridines a potentiometric investigation

A series of sulphide‐containing pyridines of general formula(CH 2 ) x SR where R = CH 3 , C 2 H 5 , CH 2 CH 2 OH and x = 1, 2 has been prepared and studied potentiometrically in the presence of Ag + in 0.5 M (K)NO 3 medium at 25°C. The complex formation is discussed in terms of the Taft σ*‐parameters for the substituents. In acid region, where the complexes AgLH 2+ and AgL 2 H 2 3+ were formed, coordination occurs through the thioether group. In neutral and alkaline medium their was evidence for the species AgL 2 H 2+ , AgL + , AgL 2 + , Ag 2 L 2 2+ and Ag 2 L 2+ in which Ag + S and Ag + bonds are involved. The five membered chelate rings for the AgL + and AgL 2+ species are found to be more stable than the six‐membered ones.