The Intrinsic3[dσ*pσ] Emission of Binuclear Gold(I) Complexes with Two Bridging Diphosphane Ligands Lies in the Near UV; Emissions in the Visible Region Are Due to Exciplexes

A near-UV triplet emission from [Au(2)(dcpm)(2)](ClO(4))(2) has been discovered. Studies on the spectroscopic properties of the complexes [Au(2)(dcpm)(2)]Y(2) (Y=ClO(4)(-), PF(6)(-), CF(3)SO(3)(-), [Au(CN)(2)](-), Cl(-), and I(-); dcpm=bis(dicyclohexylphosphanyl)methane) support the assignment of the high-energy emissions at 360-368 nm to the (3)[dsigma*psigma] excited state, adducts of which exhibit exciplex emissions in the visible region with solvent or counterions (see schematic diagram).