ABSTRACT: Heteroleptic [Cu(P^P)(N^N)][PF6] complexes, where N^N is 5,5'-dimethyl-2,2'-bipyridine (5,5'-Me2bpy), 4,5,6-trimethyl-2,2'-bipyridine (4,5,6-Me3bpy), 6-(tert-butyl)-2,2'-bipyridine (6-tBubpy) and 2-ethyl-1,10-phenanthroline (2-Etphen) and P^P is either bis(2-(diphenylphosphino)phenyl)ether (POP, PIN [oxydi(2,1-phenylene)]bis(diphenylphosphane)) or 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xantphos, PIN (9,9-dimethyl-9H-xanthene-4,5-diyl)bis(diphenylphosphane)) have been synthesized and their NMR spectroscopic, mass spectrometric, structural, electrochemical and photophysical properties were investigated. The single-crystal structures of [Cu(POP)(5,5'-Me2bpy)][PF6], [Cu(xantphos)(5,5'-Me2bpy)][PF
