Interactions of alkyltin(IV) compounds with ligands of interest in the speciation of natural fluids: Complexes of (CH3)(3)Sn+ with carboxylates

Complex formation by (CH3)(3)Sn+ with succinate, citrate, 1,2,3-propanetric arboxylate (tricarballilate), 1,2,3,4-butanetetracarboxylate and benzenehex arboxylate (mellitate), has been studied by potentiometry [(H+)-glass elect rode], at T = 25 degrees C, in NaCl aqueous solutions at different ionic st rengths, 0 < I less than or equal to 1 mol dm(-3). In all the systems studi ed ML and MHjL species are formed, and for tetra-and hexa-carboxylic ligand systems the species MIL was also found. The stability of these complexes i s quite relevant, and for the ML(1-z) a simple relationship logK = 1.27 z(0 .86) (I = 0 mol dm(-3) T = 25 degrees C) was obtained. The percentages of t he species formed in the citrate and mellitate systems are significant even at very low concentration.