Structural characterisation of [Au10Cl3(PCy2Ph)6](NO3)(Cy = cyclohexyl) and the development of a structural principle for high nuclearity gold clusters

[Au10Cl3(PCy2Ph)6](CO3) which has been synthesised in low yield from Au(NO3)(PCy2Ph) and NaBH4 has a toroidal geometry based on a hexagonal ring of edge- and face-sharing tetrahedra which share a common central vertex.