An octahedral gold cluster: crystal and molecular structure of hexakis[tris-(p-tolyl)phosphine]-octahedro-hexagold bis(tetraphenylborate)

The crystal arid molecular structure of the title compound has been determined from three-dimensional X-ray data collected by counter methods and refined by least-squares to R 0·052 from 3501 independent reflections. Crystals are triclinic, space group P, with unit cell dimensions a= 17·48(2), b= 19·02(2), c= 13·81(1)Å, α= 101·1 (1), β= 94·2(1), γ= 116·4(1)°, Z= 1. The hexanuclear dication is a centrosymmetric octahedron significantly distorted. Two mutually opposite faces have edges ranging from 2·932(2) to 2·990(2), the remaining edges ranging from 3·043(2) to 3·091 (2)Å. The overall mean Au-Au distance, 3·019 Å, is longer than the corresponding values in Au11 and Au9 clusters. These long distances do not arise from non-bonding repulsions between adjacent ligands.