摘要:
The behavior of OsH2Cl2((PPr3)-Pr-i)(2) (1) in acetonitrile as solvent is studied. Acetonitrile coordinates to the metal center of 1 and promotes the dihydride-dihydrogen transformation of its OsH2 unit to give the trans-Cl-2 compound OsCl2(eta(2)-H-2)(CH3CN)((PPr3)-Pr-i)(2) (2a), which evolves to its cis-Cl-2 isomer 2b. Treatment of 1 with TlPF6 in acetonitrile leads to the PF6 salt of the cis-bis(acetonitrile) cation [OsCl(eta(2)-H-2)(CH3CN)(2)((PPr3)-Pr-i)(2)](+) (3a), which is transformed into its trans-bis(acetonitrile) isomer 3b. The addition of Et3N to the PF6 salts of 3a,b in acetonitrile gives [OsH(CH3CN)(3)((PPr3)-Pr-i)(2)]PF6 (4). Reaction of 4 with 1,5-cyclooctadiene (COD) in refluxing toluene affords [OsH(COD)(CH3CN)(2)((PPr3)-Pr-i)]PF6 (5). The X-ray structures of 3b and 5 are also reported.