Copper(I) binap complexes (binap=(2,2′-bis(diphenylphosphino)-1,1′-binaphthyl). Luminescence from IL and LLCT states

The preparation and the r.t. luminescence of the complexes [Cu(binap)2]+ and [Cu(binap)I]2 with binap = 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl are reported. The lowest-energy excited state of [Cu(binap)2]+ is an IL ππ∗ state of the binaphthyl chromophore. The luminescence of the cation consists of a fluorescence and a phosphorescence originating from this IL state. In contrast, the dimer [Cu(binap)I]2 is characterized by a I− → binap LLCT state which occurs at lower energies than the binap IL state. The dimer shows only a single emission band. This luminescence is suggested to come from the LLCT triplet.