Synthesis, structure and electronic spectra of new three-coordinated copper(I) complexes with tricyclohexylphosphine and diimine ligands

Three new copper(I) complexes with tricyclohexylphosphine (PCy3) and different diimine ligands, [Cu(phen)(PCy3)]BF4 (1) (phen = 1,10′-phennanthroline), [Cu(bpy)(PCy3)2]BF4 (2) (bpy = 2,2′-bipyridine) and [Cu(MeO-CNN)(PCy3)]BF4 (3) (MeO-CNN = 6-(4-methoxyl)phenyl-2,2′-bipyridine), have been synthesized and characterized. X-ray structure reveals that complexes 1 and 3 are three-coordinated with trigonal geometry, while complex 2 adopts distorted tetrahedron geometry. Complexes 1 and 3 exhibit ligand redistribution reactions in chloromethane solution by addition of excess amount of PCy3, in which three-coordinated 1 changes into four-coordinated [Cu(phen)(PCy3)2]+, and 3 leads to form [Cu(PCy3)2]BF4 and CNN-OMe. All the three complexes display yellow 3MLCT emissions in solid state at room temperature with λmax at 558, 564 and 582 nm for 1, 2 and 3, respectively, and red-shift to 605, 628 and 643 nm at 77 K in dichloromethane solution.