Mm. Shoukry et al., BINARY AND TERNARY COMPLEXES OF CADMIUM(II) INVOLVING N-(2-ACETAMIDO)IMINODIACETIC ACID AND AMINO-ACIDS, Annali di chimica, 86(3-4), 1996, pp. 167-180
The present work examines the acid-base equilibria of N(2-acetamido)im
inodiacetic acid (ADA) and the binary and ternary complexes of cadmium
(II) with ADA and amino acids. Cd(II) is found to form a 1:1 complex w
ith ADA. The ternary complexes are formed in a stepwise mechanism, whe
reby the ADA binds to Cd(II), then follows ligation of the amino acid
in a glycine-like mode. The amino acids histidine, ornithine, lysine,
penicillamine, cysteine and glutathione form protonated and deprotonat
ed ternary complexes. The stability constants of the ternary complexes
have been quantified in relation to the corresponding binary complexe
s. The concentration distribution of the various complex species has b
een evaluated.