Molecular and Electronic Structure of Platinum Bis(N‐arylamino)phosphenium Complexes including [Pt(phosphane)(phosphenium)(N‐heterocyclic carbene)]

Give and take: A cationic N-heterocyclic carbene (NHC)–phosphenium adduct is prepared (see picture; orange=P, lilac=N, gray=C, white=H). On reaction with [Pt(PPh3)3] it splits into its constituent parts, delivering an NHC ligand (a strong σ donor) and a phosphenium ligand (a π acceptor) from one reagent. These first platinum phosphenium complexes are characterized by short PtP bonds and large Pt–P coupling constants.