Double E─H Bond Activation of Ammonia and Water by Cyclic Gallaphosphene L(OCP)GaPGaL.

Cyclic gallaphosphene L(PCO)GaPGaL 1 L = HC[C(MeNAr]; Ar = 2,6-i-Pr-CH) selectively reacts with NH and HO at ambient temperature with twofold N─H and O─H bond activation and formation of compounds LGa(μ-PH)(μ-NHC(O)PH)GaL 2 and LGa(μ-PH)(μ-OC(O)PH)GaL 3. Both nucleophilic P atoms of 1 are protonated in these reactions, while the electrophilic carbon atom of the bridging PCO unit binds to the remaining NH group / O atom. The formation of heterocycles 2 and 3, which were characterized by heteronuclear NMR (H, C{H}, P{H}) and IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction (sc-XRD), is only possible due to a beneficial interplay between the polar Ga─P double bond and the electrophilic nature of the C center in the bridging PCO unit. The reaction mechanism and energetics of the NH reaction was investigated in detail by quantum chemical calculations, which also highlight the importance of bimolecular reaction processes with the involvement of an additional NH molecule.