American Chemical Society
om800467v_si_001.cif (24.25 kB)

Activation of Hydrogen and Related Small Molecules by the Unsaturated Cluster Complex PtOs3(CO)7(PBut3)(μ-PBut2)(μ4-CHCMeCH)

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posted on 2008-10-13, 00:00 authored by Richard D. Adams, Erin M. Boswell, Michael B. Hall, Xinzheng Yang
Reactions of the unsaturated mixed metal cluster complex PtOs3(CO)7(PBut3)(μ-PBut2)(μ4-CHCMeCH), 1, with hydrogen, HGePh3, and PhC2H have been investigated. Compound 1 reacts reversibly with hydrogen at room temperature to yield the dihydrido complex PtOs3(CO)7(PBut3)(μ-PBut2)(μ4-CHCMeCH)(μ-H)(H), 2. A computational analysis shows that the hydrogen addition occurs by oxidative addition at the electronically unsaturated platinum atom and passes through two unstable intermediates before giving the final product 2. Compound 1 reacts with HGePh3 at the Ge−H bond to form the complex PtOs3(CO)7(PBut3)(μ-PBut2)(μ4-CHCMeCH)(GePh3)(μ-H), 3, but in this reaction the HGePh3 addition occurred at one of the osmium atoms and a CO ligand was shifted to the platinum atom. Compound 1 reacts with PhC2H by loss of the platinum atom and the PBut3 ligand to give the compound Os3(CO)7(μ-PBut2)[μ35-CHCMeC(H)CCPhH], 4. In the process, the PhC2H molecule became bonded to the CHCMeCH ligand in 1 and its hydrogen atom was shifted to the phenyl-substituted carbon atom to form a triply bridging CHCMeC(H)CCPhH ligand. All of the products were characterized by single-crystal X-ray diffraction analyses.