Aggregation and Degradation of White Phosphorus Mediated by N-Heterocyclic Carbene Nickel(0) Complexes.

The reaction of zerovalent nickel compounds with white phosphorus (P ) is a barely explored route to binary nickel phosphide clusters. Here, we show that coordinatively and electronically unsaturated N-heterocyclic carbene (NHC) nickel(0) complexes afford unusual cluster compounds with P , P , P and P units. Using [Ni(IMes) ] [IMes=1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene], electron-deficient Ni P and Ni P clusters have been isolated, which can be described as superhypercloso and hypercloso clusters according to the Wade-Mingos rules. Use of the bulkier NHC complexes [Ni(IPr) ] or [(IPr)Ni(η -toluene)] [IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene] affords a closo-Ni P cluster. Inverse-sandwich complexes [(NHC) Ni P ] (NHC=IMes, IPr) with an aromatic cyclo-P ligand were identified as additional products.