Spectrophotometric Determination of Equilibrium Constants of Dimethyl and Diethyltin(IV) Dichloride with 5,10,15,20-Tetrakis(4-trimethyl-ammonio-phenyl)-prophine Tetratosylate

The formation constant of dimethyl and diethyltin(IV) dichloride hydrolytic species and their complexation reactions with 5,10,15,20-tetrakis(4-trimethyl-ammonio-phenyl)-prophine tetratosylate (TTMAPP) were evaluated using potentiometric and spectrophotometric methods. H-1 NMR spectra of dimethyl and diethyltin(IV) at different pHs have an octahedral structure in low pHs and a distorted trigonal bipyramidal structural arrangement at higher pH values. The compositions of the formed complexes were determined, and it was shown that they form a single mononuclear 1:1 species with the ligand. The results indicate that the formation constants are in the order Me2Sn(IV)-TTMAPP > Et2Sn(IV)-TTMAPP.