Addition of H-2 Across a Cobalt-Phosphorus Bond

摘要

Addition of H-2 across the cobalt-phosphorus bond of (PPP)CoPMe3 (3) is demonstrated, where PPP is a mono-anionic diphosphine pincer ligand with a central N-heterocyclic phosphido (NHP) donor. The chlorophosphine Co-II complex ((PPP)-P-Cl)CoCl2 (2) can be generated through coordination of the chlorophosphine ligand ((PPP)-P-Cl, 1) to CoCl2. Subsequent reduction of 2 with KC8 in the presence of PMe3 generates (PPP)CoPMe3 (3), in which both the phosphorus and cobalt centers have been reduced. The addition of 1 atm of H-2 to complex 3 cleanly affords ((PPP)-P-H) Co(H)PMe3 (4), in which H-2 has ultimately been added across the metalphosphorus bond. Complex 4 was characterized spectroscopically and using computational methods to predict its geometry.