title: Equilibrium studies of organotin(IV) complexes with vitamin B(6).
abstract: The complex-formation equilibria of dimethyltin(IV), trimethyltin(IV) and tributyltin(IV) with pyridoxamine were investigated in dioxane-water mixtures and at different temperatures using a potentiometric technique. The stepwise formation constants of the complexes formed in solution were calculated using the non-linear least-square program MINIQUAD-75. The effect of dioxane as a solvent on the protonation constants of pyridoxamine and the formation constants of organotin(IV) complexes was discussed. The thermodynamic parameters DeltaH degrees and DeltaS degrees calculated from the temperature dependence of the equilibrium constants were investigated. The concentration distribution of the various complex species was evaluated as a function of pH.
authors.affiliation: Department of Chemistry, Faculty of Science, Cairo University, Giza, Cairo, Egypt.
authors.forename: M M
authors.initials: MM
authors.lastname: Shoukry
authors.forename: E M
authors.initials: EM
authors.lastname: Khairy
authors.forename: M M
authors.initials: MM
authors.lastname: Mohamed