The reversible transformation of substrates by several electron equivalents is a key goal of chemical energy storage. 1 Toward this aim, extensive effort has been devoted to study catalysts that mediate the multi-electron reduction of substrates including protons, CO 2 and N 2 . 2 In order to achieve such transformations with minimal energy input, catalysts that operate at low overpotentials are desired. Toward this end, we 3 and others 4 have been investigating cobalt tetra-imine ...
