Thermodynamics of hydroxo complex formation of dialkyltin(IV) ions in aqueous solution

Abstract

The hydrolysis of [SnMe₂]²⁺ and [SnEt₂]²⁺ has been investigated, both potentiometrically and calorimetrically, at 25 °C and I= 0.1 mol dm^–3(KNO₃). The species formed, together with their stability constants, have been determined by analysing a total of 550 and 300 potentiometric data points, for dimethyltin and diethyltin respectively, using two different computer programs. The results are critically compared with literature data obtained under analogous experimental conditions. In addition, ΔH^⊖ and ΔS^⊖ values for the main species formed at the concentrations investigated have been obtained by means of calorimetric measurements. Bonding details of the hydroxo species have been inferred on the basis of the enthalpic and entropic changes.