Mononuclear copper(I) complexes bearing 1,3-bis(diphenylphosphino)propane and functional 6-Cyano-2,2′-bipyridine ligands

•Two new mono-Cu(I) complexes of functional 6-cyano-2,2′-bipyridine were prepared.•Two complexes show a distorted N2P2 tetrahedron and are emissive in solid state.•Methylation of 2,2′-bipyridine is favorable for improving the emission properties.