A "push‐pull" stabilized phosphinidene stabilized by a β‐diketiminato ligand

We describe the use of a bis(diphenyl)phosphine functionalized β-diketiminato ligand, [HC{(CH3)C}2{(ortho-[P(C6H5)2]2C6H4)N}2]− (PNac), as a support for germanium(II) and tin(II) chloride and phosphaketene compounds. The conformational flexibility and hemilability of this unique ligand provide a versatile coordination environment that can accommodate the electronic needs of the ligated elements. For example, chloride abstraction from [(PNac)ECl] (E = Ge, Sb) affords the cationic germyliumylidene and stannyliumylidene species [(PNac)E]+ in which the pendant phosphine arms associate more strongly with the Lewis acidic main group element centres providing further electronic stabilisation. In a similar fashion, chemical decarbonylation of the germanium phosphaketene [(PNac)Ge(PCO)] with tris(pentafluorophenyl)borane affords a “push-pull” stabilized phosphinidene in which one of the phosphine groups of the ligand backbone associates with the low valent phosphinidene centre.