Four-electron reduction of dioxygen catalysed by dinuclear cobalt complexes bridged by bis(terpyridyl)anthracene.

Dinuclear cobalt-1,10-phenanthroline (1) and 2,2'-bipyridine (2) complexes bridged by 1,8-bis(2,2':6',2''-terpyrid-4'-yl)anthracene (btpyan) were prepared. Both of the complexes selectively catalysed the electrochemical four-electron reduction of dioxygen to H2O without the generation of H2O2 as a two-electron reduction product.