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 Co(3+) complex of pyridine-amide ligand as building blocks for the assembly of heterobimetallic complexes. These Co(3+)-centered building blocks orient the tethered pyridine groups to a preorganized cleft that successively coordinates to the Cd(2+) and Hg(2+) ions in the periphery. Both {Cd(2+)-Co(3+)-Cd(2+)} and {Hg(2+)-Co(3+)-Hg(2+)} heterobimetallic complexes have been thoroughly characterized, including crystal structures depicting interesting weak interactions in the solid state. The {Cd(2+)-Co(3+)-Cd(2+)} and {Hg(2+)-Co(3+)-Hg(2+)} 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.