Addition of H 2 Across a Cobalt-Phosphorus Bond

Addition of H across the cobalt-phosphorus bond of (PPP)CoPMe (3) is demonstrated, where PPP is a monoanionic diphosphine pincer ligand with a central N-heterocyclic phosphido (NHP ) donor. The chlorophosphine Co complex (PP P)CoCl (2) can be generated through coordination of the chlorophosphine ligand (PP P, 1) to CoCl . Subsequent reduction of 2 with KC in the presence of PMe generates (PPP)CoPMe (3), in which both the phosphorus and cobalt centers have been reduced. The addition of 1 atm of H to complex 3 cleanly affords (PP P)Co(H)PMe (4), in which H has ultimately been added across the metal-phosphorus bond. Complex 4 was characterized spectroscopically and using computational methods to predict its geometry.