Stereoselectivity of N-carboxymethyl-amino acid complexes of copper(II) toward optically active amino acids

Abstract

The stability constants for a series of mixed, labile copper(II) complexes of amino acids and amino acid derivatives are reported. These constants indicate that Cu(II) complexes of N-carboxymethyl- L-valine, - L-isoleucine, or - L-serine or Cu(II) complexes of N-benzyl-N-carboxymethyl- L-alanine or - L-leucine coordinate L-valine, L-leucine, or L-threonine more strongly than their D isomers. N-carboxymethyl- L-aspartic acid, - L-glutamic acid and - D-valine show opposite preferences. These results are discussed in terms of amine proton interactions between the ligands bound to the copper.