Studies of the Mixed Amino Acid Complexes of Cobalt(III). III. Absorption and Circular Dichroism Spectra of Bis(amino acidato)ethylenediamine cobalt(III) and Bis(amino acidato)oxalatocobaltate(III) Complexes

Abstract

Abstract Three isomers of cis(O)-bis(l-alaninato)ethylenediaminecobalt(III) perchlorate, four isomers of potassium cis(N)-bis(l-alaninato)oxalatocobaltate(III) and two isomers of potassium trans(N)-bis(l-prolinato)oxalatocobaltate(III) have been prepared, and their configurations have been assigned by absorption and circular dichroism spectra. From analysis of the circular dichroism spectra of about 25 complexes of these types (the aminoacidato ligands are glycinato, l-alaninato, l-serinato and l-prolinato), the configurational and the vicinal circular dichroism curves have been separated and discussed. The vicinal circular dichroism curve shows a pattern characteristic of the absolute configuration of α-aminoacidato ligand and of the geometrical structure of the complex.