Crystallographic Studies of Synthetic Corrinoids. III. Structural similarities and differences between A/D‐seco‐corrinoid complexes of divalent nickel, palladium and platinum

Abstract

Abstract X‐ray crystal structure investigations of the isomorphous perchlorate salts of complexes of an A/D‐seco‐corrinoid ligand (I) with divalent nickel, palladium and platinum are reported. The structures determined for the Pd‐ and Pt‐complexes are virtually superposable, that of the Ni‐complex, although similar to the other two, shows significant differences with respect to metal coordination and to the spatial relationship of the A and D rings and their substituents. These similarities and differences are discussed in relation to the photochemical A/D cyclization leading to corrin complexes (II).