Asymmetric Induction in Cobaloxime Complex Crystals Due to Chiral Crystal Environment

The achiral 2-cyanoethyl group of cobaloxime complexes was isomerized to the chiral 1-cyanoethyl group on exposure to a xenon lamp in the solid state. From the crystal structures and the enantiomer or diastereomer excesses of the seven cobaloxime complexes with different axial base ligands, it was found that the chirality of the produced 1-cyanoethyl group depends on the asymmetric shape of the reaction cavity for the 2-cyanoethyl group before irradiation.