Cobalt Complex as Building Blocks: Synthesis, Characterization, and Catalytic Applications of {Cd²⁺−Co³⁺−Cd²⁺} and {Hg²⁺−Co³⁺−Hg²⁺} Heterobimetallic Complexes

The present work demonstrates the utilization of the Co3+ complex of pyridine−amide ligand as building blocks for the assembly of heterobimetallic complexes. These Co3+-centered building blocks orient the tethered pyridine groups to a preorganized cleft that successively coordinates to the Cd2+ and Hg2+ ions in the periphery. Both {Cd2+−Co3+−Cd2+} and {Hg2+−Co3+−Hg2+} heterobimetallic complexes have been thoroughly characterized, including crystal structures depicting interesting weak interactions in the solid state. The {Cd2+−Co3+−Cd2+} and {Hg2+−Co3+−Hg2+} heterobimetallic complexes have been further used for the catalytic cyanosilylation of imines and ring-opening reactions of oxiranes and thiiranes. The results suggest peripheral metal-selective catalytic reactions.