Synthesis, Structure, and Reactivity of Carbene-Stabilized Phosphorus(III)-Centered Trications [L3P]3+

Carbene-stabilized [L3P]+3 cations have been synthesized for the first time by a reaction between 1-chloro-2,3-bis(dialkylamino)cyclopropenium salts and P(SiMe3)3. In addition, the first structural characterization of such an entity is reported. Consistent with the X-ray data, density functional calculations indicate that these P-centered cations, despite their high positive charge, still feature a nonbonding electron pair on the P-atom (HOMO) and a very low-lying LUMO depicting them as poor σ-donors and excellent π-acceptors.