CHEMISTRY OF MU MERCAPTODIBORANE

Treatment of solid [(C2H6)4N] [HS(BH3)2] with anhydrous hydrogen chloride at -78° produces hydrogen and the new compound μ-mercaptodiborane, μ-HSB2H5. The bridge structure of μ-mercaptodiborane is confirmed by the 11B nmr spectrum. Thermal decomposition of μ-mercaptodiborane in the gas phase at low pressure yields diborane, hydrogen sulfide, and involatile products. Liquid-phase decomposition results in the formation of diborane, hydrogen, and an involatile glassy solid. In the gas phase μ-mercaptodiborane undergoes boron isotope exchange with 10B2H6. Treatment of μ-mercaptodiborane with excess liquid deuterium chloride at -78° produces μ-DSB2H5. The liquid-phase decomposition of μ-DSB2H5 produces mainly HD, while gas-phase decomposition yields hydrogen sulfide containing deuterium and B2H6. The rate of decomposition of μ-mercaptodiborane in the gas phase is insensitive to the presence of diborane. © 1969, American Chemical Society. All rights reserved.