Synthesis and Characterization of Stable Gold(III) PNP Pincer Complexes

The first mononuclear Au III PNP pincer complexes [PNP = bis(2‐diisopropylphosphinophenyl)amide] are reported. The chloro complex [(PNP)Au(Cl)][OAc F ] (OAc F = OCOCF 3 ) was synthesized by microwave irradiation of a tetrachloroaurate salt and the neutral PN H P ligand. Dehalogenation with AgOAc F afforded the trifluoroacetate‐bound complex [(PNP)Au(OAc F )][OAc F ]. Both complexes were characterized by NMR spectroscopy and X‐ray crystallography. Electronic absorption spectroscopy and TD‐DFT studies assigned the electronic transition that imbues the complexes with a deep royal blue color. The Au III trifluoroacetate complex is surprisingly stable, and no alkene insertion was observed under ethylene (C 2 H 4 ), even under high pressures and at high temperatures. DFT calculations suggest that the lack of reactivity is due to the high energy of the putative dicationic C 2 H 4 ‐bound intermediate invoked in a formal insertion reaction.