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

Abstract

The reaction of zerovalent nickel compounds with white phosphorus (P₄ ) 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 P₁ , P₃ , P₅ and P₈ units. Using [Ni(IMes)₂ ] [IMes=1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene], electron-deficient Ni₃ P₄ and Ni₃ P₆ 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)₂ ] or [(IPr)Ni(η⁶ -toluene)] [IPr=1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene] affords a closo-Ni₃ P₈ cluster. Inverse-sandwich complexes [(NHC)₂ Ni₂ P₅ ] (NHC=IMes, IPr) with an aromatic cyclo-P₅ ^- ligand were identified as additional products.