The preparation and stereochemistry of the ternary cobalt(III) complex of (2R,2'S)-2,2'-ethylene-bis(2-aminobutanoic) acid and ethylenediamine

Abstract

The ternary cobalt(III) complex [Co(EDDB)(en)]+ was prepared by oxidation of an aqueous solution of a cobalt(II) salt and the ligands by an equimolar amount of PbO2. Chromatographic separation on a cation exchanger yielded two geometric isomers, that were characterized by their electronic absorption, 13C NMR and IR spectra. Gel permeation chromatography was used to partially separate the two geometric isomers to yield the corresponding enantiomers, whose absolute configuration was found by CD.