A luminescent copper(I) bromide complex chelated with 4,5- bis(diphenylphosphano)-9,9-dimethyl-xanthene

The 1 : 1 molar-ratio reaction between copper(I) bromide and 4,5-bis(diphenylphosphano)-9,9-dimethyl-xanthene (xantphos) in acetonitrile results in the formation of [CuBr(xantphos)], which displays luminescent emission at room temperature. The molecular structure of the complex, established by single-crystal X-ray diffraction, features a trigonal planar geometry around the metal center, with the diphosphane acting as a chelate. The high rigidity and steric requirements of the xanthene unit rationalize the unusual coordination number of CuI.