Preparation and Circular Dichroism of <i>trans(N)</i>- and <i>cis(N)</i>-Isomers of (Ammoniatriacetato)(amino-acidato)cobalt(III) Complexes

Abstract

Abstract Eleven new complexes, trans(N)- or cis(N)-isomers of (ammoniatriacetato)(amino-acidato)cobalt(III) ions, have been synthesized as their potassium salts, where the amino acids are glycine, β-alanine, γ-aminobutyric acid, sarcosine, l-alanine, l-serine, l-valine and l-proline. The geometrical isomers have been separated by ion-exchange column chromatography and their structures determined on the basis of their absorption spectra and proton magnetic resonance spectra. Stereoselectivity about the formation of the trans and cis isomers was found. The circular dichroism of the complexes containing optically active amino acidato ligands has been measured and discussed in relation to so-called vicinal contribution by the optically active ligands.