Mm. Shoukry et Mmh. Mohamed, EQUILIBRIUM STUDIES OF DIBUTYLTIN(IV) COMPLEXES WITH AMINO-ACIDS AND PEPTIDES, Silicon, germanium, tin and lead compounds, 20(5), 1997, pp. 281-292
Complex formation equilibria of dibutyltin(IV) with amino acids and pe
ptides have been investigated. Stoichiometry and stability constants f
or the complexes formed were determined at 25 degrees C and ionic stre
ngth 0.1 M NaNO3. The results showed the formation of 1:1 and 1:2 (org
anotin : ligand) complexes with amino acids. The effect of the pK(a) v
alue of the amino acid on the stability,constant of its complex specie
s was elucidated. Peptides form both 1:1 complexes and the correspondi
ng deprotonated amide species. In the latter species the binding with
dibutyltin(IV) :occurs through the terminal amino group, carboxylate o
xygen and the amide nitrogen atoms. The concentration distribution of
the complexes in solution was evaluated.