Five-co-ordinated gold(III) complexes. Part 1. Synthesis, structure, and properties of bromodicyano(1,10-phenanthroline)gold(III)–dimethylformamide (1/1)

Abstract

The five-co-ordinated gold(III) complex bromodicyano(1,10-phenanthroline)gold(III)–dimethylformamide (1/1) has been synthesized by reaction between trans-[Au(CN)₂Br₂]^– and 1,10-phenanthroline in water, followed by crystallization from dimethylformamide–diethyl ether at low temperature. The crystal structure has been determined by X-ray analysis from three-dimensional counter data, and refined by full-matrix least squares to R= 0.032 for 3 833 independent reflections. Crystals are triclinic, space group P, with a= 8.524(2), b= 9.708(4), c= 12.525(5)Å, α= 80.78(3), β= 106.79(3), γ= 110.86(3)°, and Z= 2. The co-ordination around the metal is distorted square pyramidal with the four basal atoms (one bromide atom, two carbon atoms from the cyano groups, and one nitrogen atom of the bidentate phenanthroline) nearly coplanar. The gold atom lies 0.058 Å above the base and the apical nitrogen atom is displaced from the vertical and at a relatively great distance from the metal. The dimethylformamide molecule of crystallization is connected in the structure by C–H ⋯ O hydrogen bonds. The crystallographic results are related to other physical measurements.