Synthesis, characterization, crystal structure determination, and luminescence properties of two new gold(III) complexes with phenanthridine ligand

Abstract

Two new gold(III) complexes of phenanthridine (phend) ligand, gold(III) trichlorophenanthridine ([Au(phend)Cl3]) and gold(III) tribromophenanthridine ([Au(phend)Br3]), have been synthesized from the reaction of HAuCl4∙3H2O and AuBr3 with phend, respectively, and characterized by elemental analysis, luminescence, IR, 1H and 13C NMR spectroscopy, and their structures were studied by the single-crystal diffraction method. [Au(phend)Cl3] crystallizes in the space group P21/n of the monoclinic system with a = 7.6661(7) A, b = 20.816(2) A, c = 17.4906(16) A, β = 98.500(7)°, and Z = 8. [Au(phend)Br3] crystallizes in the space group Pī of the triclinic system with a = 10.2137(4) A, b = 11.1191(4) A, c = 14.6540(6) A, α = 68.631(3), β = 71.706(3), γ = 66.098(3)°, and Z = 4. There are two molecules of the complex in the asymmetric units and in both molecules, the geometry at the gold(III) centers is square planar, formed by one nitrogen atom of phend and three chloride or bromide ions. Weak hydrogen bonding, π–π interaction, together with interhalogen contact, may play an important role in determining the structure of both complexes.