Luminescent Mononuclear Copper(I) Diphosphine Complexes with 6-Methoxycarbonyl-4,4′-dimethyl-2,2′-bipyridine

Two new mononuclear copper(I) diphosphine complexes based on 6-methoxycarbonyl-4,4'-dimethyl-2,2'-bipyridine (mmbpy), [Cu(mmbpy)(dppp)]ClO4 (1) and [Cu(mmbpy)(dppb)]ClO4 (2), have been synthesized and characterized. It is revealed that Cu(I) complexes 1 and 2 all exhibit distorted N2P2 tetrahedral geometries with varied P-Cu-P angles regulated by auxiliary diphosphine ligands. The two Cu(I) complexes are all emissive in the solid state at ambient temperature, and their photophysical properties are more markedly influenced by the P-Cu-P angle than the methylene chain length of diphosphine. It is also demonstrated that the introduction of two methyl substituents into the 2,2'-bipyridyl ring is effective for improving luminescence properties of Cu(I) complexes. CCDC: 1543374, 1; 1543375, 2.