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

The reaction of zerovalent nickel compounds with white phosphorus (P(4)) 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(1), P(3), P(5) and P(8) units. Using [Ni(IMes)(2)] [IMes=1,3‐bis(2,4,6‐trimethylphenyl)imidazolin‐2‐ylidene], electron‐deficient Ni(3)P(4) and Ni(3)P(6) 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(η(6)‐toluene)] [IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene] affords a closo‐Ni(3)P(8) cluster. Inverse‐sandwich complexes [(NHC)(2)Ni(2)P(5)] (NHC=IMes, IPr) with an aromatic cyclo‐P(5) (−) ligand were identified as additional products.