Synthesis and Characterization of Copper(I) Complexes with Triazole Derivative Ligands Containing an α-Diimine Moiety

Abstract

Two cuprous complexes Cu(L1)(PPh3)I (1) and Cu(L2)(PPh3)I (2) were obtained by reaction of Cu(PPh3)3I (PPh3 = triphenylphosphine) with two different α-diimine ligands L 1 (3,5-di(2′-pyridyl)-4-amino-1,2,4-triazole) and L 2 (N-benzylidene-3,5-di (2′-pyridyl)-4-amino-1,2,4-triazole, respectively. These two complexes have been characterized by UV-Vis, luminescence, 1 H NMR spectroscopy and cyclic voltammetric studies. The structures are confirmed by the single crystal X-ray diffraction study. The compound Cu(L1)(PPh3)I (1) crystallizes in the triclinic space group P-1 with a = 8.3188(14), b = 9.2243(15), c = 21.177(4), α = 78.156(3), β = 86.45(3), γ = 65.966(3), Z = 2 and the compound Cu(L2)(PPh3)I (2) crystallizes in the triclinic space group P-1 with a = 8.9671(7), b = 13.9737(11), c = 14.6850(12), α = 82.2580(10), β = 75.7020(10), γ = 72.2790(10), Z = 2. Both complexes show an MLCT band at 340 ∼ 545 nm region and complex 2 exhibits luminescence at room temperature in a dichloromethane solution. The cyclic voltammogram of Cu(L1)(PPh3)I shows the redox couples at + 0.36 and − 0.545 V.