Polyhedral ruthenaborane chemistry. Approaches to encapsulated boron cores. The isolation and characterisation of the partially encapsulated isocloso 10-vertex {RuB9} cluster compound [(PPh3)RuB9H9{RuCl2(PPh3)2}2]

[RuCl2(Ph3)2] with [arachno-B9H14]− gives [(PPh3)RuB9H9{RuCl2(PPh3)2}2], which has an isocloso 10-vertex {RuB9} core geometry that is partially encapsulated by exo-polyhedral {RuCl2(PPh3)2} units that cap {RuB2} triangular faces with one {RuClRu} and two {RuHB} bridges each. The structure engenders focus on the several new compound classes emerging in polyhedral boron-containing cluster chemistry.