Preparation of a Dihydrogen Complex of Cobalt

H2 & Co.: A new pincer complex of CoII has been synthesized. Reduction of this complex in the absence of additional ligands results in the formation of a highly reactive mercury-bridged dicobalt species (1). Subsequent introduction of H2 at low temperature allows the observation of a rare dihydrogen complex of Co (2). Co blue, P yellow, O red, Hg dark gray.