Nickel Phosphinidene Molecular Clusters from Organocyclophosphine Precursors.

We report a new family of nickel phosphinidene molecular clusters synthesized from the reaction of bis(1,5-cyclooctadiene)nickel(0) ([Ni(cod)2 ]) with organocyclophosphine and trialkylphosphine. We found that [Ni(cod)2 ] cleaves the organocyclophosphine P-P bonds to generate phosphinidene groups, establishing the cyclic molecules as valuable precursors for making charge-neutral molecular clusters passivated by two-electron donor capping ligands. The formation of the cluster core structure is controlled by the bulkiness of the precursor and of the capping ligand. As a demonstration of this new cluster-forming reaction, we describe three clusters with different core nuclearity and degree of ligation: Ni12 (PMe)10 (PEt3 )8 , Ni8 (PMe)6 (PMe3 )8 , and Ni8 (PiPr)6 (PMe3 )6 . In addition, we show that the larger cluster, Ni12 (PMe)10 (PEt3 )8 , can be used as a low temperature single-source molecular precursor to the catalytically active nickel phosphide phase Ni2 P.