Photoinitiated Charge Transfer in a Triangular Silver(I) Hydride Complex and its Oxophilicity.

The photoexcitation of a triangular silver(I) hydride complex, [Ag-3(mu(3)-H)(mu(2)-dcpm)(3)](PF6)(2) ([P](PF6)(2), dcpm=bis(dicyclohexylphosphino)methane), designed with "UV-silent" bis-phosphine ligands, provokes hydride-to-Ag-3 single and double electron transfer. The nature of the electronic transitions has been authenticated by absorption and photodissociation spectroscopy in parallel with high-level quantum-chemical computations utilizing the GW method and Bethe-Salpeter equation (GW-BSE). Specific photofragments of mass-selected [P](2+) ions testify to charge transfer and competing pathways resulting from the unique [Ag-3(mu(3)-H)](2+) scaffold. This structural motif of [P](PF6)(2) has been unequivocally verified by H-1 NMR spectroscopy in concert with DFT and X-ray diffraction structural analysis, which revealed short equilateral Ag-Ag distances (d(AgAg)=3.08 angstrom) within the range of argentophilic interactions. The reduced radical cation [P](.)(+) exhibits strong oxophilicity, forming [P+O-2](.+),which is a model intermediate for silver oxidation catalysis.