Cobalt(III) complex of ethylenediamine-N,N′-bis-α-(β-phenyl)-propionic acid

A novel optically active ONNO-type tetradentate ligand, ethylenediamine-N,N′-bis-α-(β-phenyl)-propionic acid (edbp), and its cobalt(III) complex have been synthesized via the PbO₂ oxidation method. During the preparation of diaqua cobalt(III) complexes of edbp, [Co(edbp)(H₂O)₂]⁺, the ligand has coordinated specifically to the cobalt(III) ion to give only one isomer, cis-α, which has been characterized by electronic absorption, ¹H NMR and IR spectra, and elemental analysis. It is of interest that this is one of the few Co^III (edda)X₂ type complex preparations, which gives only one isomer with stereospecificity.