Cobalt Clathrochelate Complexes as Hydrogen‐Producing Catalysts

Wrapper's delight: Clathrochelate complexes, in which the metal center is wrapped in a close-knit macrobicyclic ligand, are often considered to be deprived of chemical reactivity. Boron-capped cobalt tris(glyoximato) complexes show catalytic activity in the reduction of acids in acetonitrile at potentials as small as −0.5 V versus SCE. Alteration of ligand substituents allows for the tuning of their electrochemical reactivity (see structure: red ball Co, grey C, purple B, blue N, red O, green X).