Synthesis and characterization of Cu(I) and Cu(II) complexes containing ketiminate ligands

Abstract A series of Cu(I) and Cu(II) complexes containing substituted ketiminate ligands was synthesized. Reaction of CuCl 2 with 2 equiv. of Li[OC(Me)CHC(Me)N(Ar)] in toluene generated dark green solid of Cu[OC(Me)CHC(Me)N(Ar)] 2 ( 1 ). Similarly, Cu(I) complex, {Cu[OC(Me)CHC(Me)N(Ar)]Li[OC(Me)CHC(Me)N(Ar)]} 2 ( 2 ) was synthesized by reacting 2 equiv. of Li[OC(Me)CHC(Me)N(Ar)] with CuCl in toluene at room temperature for 12 h. While the reaction of CuCl with Li[OC(Me)CHC(Me)N(Ar)] in the presence of triphenylphosphine in THF solution at room temperature, a three-coordinated Cu[OC(Me)CHC(Me)N(Ar)](PPh 3 ) ( 3 ) can be isolated in high yield. Replacing the PPh 3 of 3 with N -heterocarbene (NHC) generates Cu[OC(Me)CHC(Me)N(Ar)](NHC) ( 4 ) in low yield. Complexes 2 , 3 , and 4 were characterized by 1 H and 13 C NMR spectroscopies and all molecules were structurally characterized by X-ray diffractometry. Two coordination modes of ketiminate ligands were found in the molecular structure of 2 , one of which is copper-coordinated terminal ketiminates and the other is lithium–copper-coordinated bridging ketiminates.