A “push–pull” stabilized phosphinidene supported by a phosphine‐functionalized β‐diketiminato ligand

The use of a bis(diphenyl)phosphine functionalized &beta;‐diketiminato ligand, [HC{(CH3)C}2{(ortho‐[P(C6H5)2]2C6H4)N}2]&minus;&nbsp;(PNac), as a support for germanium(II) and tin(II) chloride and phosphaketene compounds, is described. 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, Sn) affords the cationic germyliumylidene and stannyliumylidene species [(PNac)E]+&nbsp;in which the pendant phosphine arms associate more strongly with the Lewis acidic main group element centers, providing further electronic stabilization. In a similar fashion, chemical decarbonylation of the germanium phosphaketene [(PNac)Ge(PCO)] with tris(pentafluorophenyl)borane affords a &ldquo;push&ndash;pull&rdquo; stabilized phosphinidene in which one of the phosphine groups of the ligand backbone associates with the low valent phosphinidene center.</p