PHOTOCHEMISTRY OF TRANSITION-METAL POLYHYDRIDES: DIMERIZATION OF OsH4(PMe2Ph)3 FOLLOWING PHOTODISSOCIATION OF DIHYDROGEN

Article abstract of DOI:10.1016/S0022-328X(00)98584-X

UV (254 nm) photolysis of OsH4P3 (P <*> PMe2Ph) proceeds, by photodissociation of H2, to give the transient OsH2P3.This species exchanges deuterium with C6D6, reacts with phosphine to give cis-H2OsP4, and with OsHxP3 to give Os2H2(μ-H)2P6, whose structure was determined by X-ray diffraction.This Os=Os dimer participates in a unique reversible (25 deg C) phosphine dissociation equilibrium to produce Os2H4P5, containing an Os<*>Os bond.A structural analog of this dimer was produced by acidolysis of Os2H4P6 to give Os2H3P6⁺, which X-ray diffraction reveals to have aP3Os(μ-H)3OsP3⁺ structure.