Formation and Structure of an Anionic Ruthenaborane Compound: [Et4N][(PPh3)2ClRuB12H12]

The title compound, [Et4N][(PPh3)(2)ClRuB12H12], was unexpectedly isolated from the reaction of RuCl2(PPh3)(3) with closo-B10H102- in ethanol as a red air-stable solid, and characterized by IR and a single crystal X-ray diffraction analysis. Its formation results from the reaction of RuCl2(PPh3)(3) and B12H122- which was present as a byproduct in the preparation of B10H102-. It may be formally regarded as either a ruthenium(II) complex of closo-B12H122- via three B-H-Ru three-center two-electron bonds, or as a 13-vertex pileo 2n-electron (n is the number of vertices) ruthenaborane cluster with a capped closo polyhedral skelecton. This is the first anionic and structurally characterized metal complex having a {RuB12H122-} moiety.