Cobalt(III) and chromium(III) complexes of N-(2-Aminoethyl)salicylaldimine: Crystal structure and resolution of the racemates

Abstract

The cobalt(III) and chromium(III) complexes of N-(2- aminoethyl)salicylaldimine, M(salen)₂⁺, have been resolved into their optical isomers. The electronic absorption spectra and circular dichroism spectra of the complexes have been measured for solutions in water and ethanol and assignments for the absorption bands proposed. The crystal structure of the racemate, Co(salen)₂I,H₂O, has been determined from three-dimensional X-ray diffraction data. The crystals are monoclinic, space group P2₁/c with a 18.386(1), b 10.216(1), c 12.004(1) Ǻ, β 109.87(1)°, Z 4. The structure was solved by the heavy- atom method and refined by least-squares techniques to R 0.098 for 4493 reflections (63.5% observed). The cobalt atom is octahedrally coordinated by two tridentate ligands in the meridional configuration.