A photoluminescent metallophane [Cu2(μ-dppb)2(CH3CN)4](BF4)2 with a chair conformation: synthesis, structural and spectroscopic studies

A dinuclear copper(I) complex [Cu2(μ-dppb)2(CH3CN)4](BF4)2 (dppb=1,4-bis(diphenylphosphino)benzene) has been prepared and characterized by X-ray crystallography, absorption and luminescence spectrometry. The two copper atoms are double linked by two dppb ligands to form a metallophane with the two bridging phenyl rings parallel to each other. The core cyclophane-like structure adopts a chair conformation constructed by four coplanar P atoms and two phenyl rings from two dppb ligands, and the two copper atoms located above and below the mean plane. At room temperature, the complex in solid state exhibits photoluminescence originated from the intraligand excited state perturbed by copper coordination. The title complex may serve as a pre-organized dimetal building block for constructing novel supramolecular system.