Synthesis, characterization and optical properties of a series of binuclear copper chalcogenolato complexes

A series of isolated binuclear copper(I) thiolate and selenolate complexes [Cu2(ER)2(dpppt)2] (1, E = S, R = C4H3S; 2, E = S, R = p-C6H4OMe; 3, E = Se, R = C6H5; 4, E = Se, R = p-C6H4SMe; 5, E = Se, R = p-C6H4NMe2) was synthesized. It was found that the luminescence of these complexes could be modulated by the chalcogenolate ligands. The five complexes show optical transitions with HOMO–LUMO gaps of ca. 2.95 eV (1), 2.82 eV (2), 2.99 eV (3), 2.95 eV (4) and 2.64 eV (5), respectively. Two of them (2 and 5) show a significant luminescence at room temperature at 465 or 480 nm, respectively. This might most probably result from the influence of the electron donating nature of the substituents –OMe and –NMe2.