Synthesis, characterization, and photoluminescent studies of three-coordinate Cu(i)-NHC complexes bearing unsymmetrically-substituted dipyridylamine ligands.

A series of heteroleptic three-coordinate Cu(i) complexes bearing monodentate N-heterocyclic carbene (NHC) ligands of the type 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) and 1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene (SIPr), and bidentate N-donor ligands of the type unsymmetrically-substituted dimethyl dipyridylamine (MeHdpa) and bis(mesityl)biazanaphthenequinone (mesBIAN) have been synthesized. The complexes [Cu(IPr)(3,4'-MeHdpa)]PF, 1; [Cu(IPr)(3,5'-MeHdpa)]PF, 2; [Cu(IPr)(3,6'-MeHdpa)]PF, 3; [Cu(IPr)(mesBIAN)]PF, 6; [Cu(SIPr)(3,4'-MeHdpa)]PF, 7; [Cu(SIPr)(3,5'-MeHdpa)]PF, 8; and [Cu(SIPr)(3,3'-MeHdpa)]PF, 11 have been characterized by H and C NMR spectroscopies, elemental analysis, cyclic voltammetry, and photophysical studies in solid and solution phase. Single crystal X-ray structures were obtained for all complexes except 11.