A study of the effect of amino acid structure on the stabilities of the complexes formed with metals of group II of the periodic classification

In a previous structural study of stability constants of oc-amino acid metal complexes In this paper the work is extended to a wide range of a-amino acids to discover the effect of different functional groups. Most of the amino acids are closely related to a-alanine and norvaline. Albert (1952) has published stability constants for the complexes of a number of these amino acids with a selection of metal ions. In the present work only the metals beryllium, zinc, cadmium and mercury of group II of the periodic classifieation were used. EXPERIMENTAL Materials. The following A.R. salts were used in 0-01M solution: BeSOj, 4H20; ZnSO4, 7H20; 3CdSO4, 8H,20. Hg(NO3)2 was made up in 0-025a-EHNO, and excess acid back-titrated in the presence ofthe amino acid investigated.