Affiliation: | a Department of Chemistry, Physics and Materials Technology, Technological Institution of Athens, Egaleo, Athens, Greece b Department of Chemistry, University of Patras, 26500, Patra, Greece c Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Que., H3A 2K6, Canada d Laboratory of Inorganic and General Chemistry, Department of Chemistry, University of Ioannina, 45110, Ioannina, Greece |
Abstract: | The first 1:2 metal complexes of 2-(2′-pyridyl)quinoxaline (L) have been isolated. The physical and spectroscopic characteristics of the compounds [MCl2L2] (M = Ni, Cu, Cd) and [CuIL2](PF6) are described. The structure of the copper(I) complex has been determined by X-ray diffraction methods. Crystals are orthorhombic, space group Pcnb with A = 11.014(2), B = 12.886(2), C = 17.806(4) Å, V = 2527.1(9) Å3 and Z = 4. Refinement of the structure gave a final R factor of 0.046 (Rw = 0.041) for 814 unique reflections having I > 2.0σ(I). The ligand L acts as a bidentate chelate, the ligated atoms being the pyridine nitrogen and the nearest quinoxaline nitrogen. The structure of [CuL2]+ consists of a distorted tetrahedral arrangement around the copper(I) atom with Cu---N bond lengths of 2.023(6) and 2.059(5) Å and the N---Cu---N angle of the chelating ligand equal to 80.6(2)°. A monomeric trans pseudo-octahedral stereochemistry is assigned for the [MCl2L2] complexes. |