Asymmetric induction in cobaloxime complex crystals due to chiral crystal environment

The achiral 2-cyanoethyl group of cobaloxime complexes was isomerized to th e chiral I-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 f ound that the chirality of the produced l-cyanoethyl group depends on the a symmetric shape of the reaction cavity for the 2-cyanoethyl group before ir radiation. (C) 2000 Elsevier Science Ltd. All rights reserved.