Triosmium dodecacarbonyl, reaction with

Reaction of acetylenic complexes with triosmium dodecacarbonyl leads to a variety of products involving one, two, or three acetylenic units. As with ruthenium, for the monosubstituted alkynes, hydrogen transfer can occur to the metal cluster. Thus, Os3(CO)12 and phenyl-acetylene (L) yield, in refluxing benzene, the derivatives Os3(CO)10L, Os3(CO)10L2, Os3(CO)9L, and HOs3(CO)9(L-H). The general chemistry is summarized in Scheme 2 (131). 

The reaction is run in a 250-mL flat-bottomed three-necked flask containing a magnetic stirrer and equipped with a gas inlet tube and a reflux condenser connected to a mercury check-valve to ventilate evolved gases. Octane is dried over sodium and freshly distilled before use. Triosmium-dodecacarbonyl and cyclopentadienylnickelcarbonyl dimer are commercially available (Strem). Alternatively, Os3(CO)12 may be synthesized from commercially available materials by a tested procedure.1... 

Important pioneer work in the synthesis of polynuclear metal carbonyls was made by reduction of simple metal salts in the presence of carbon monoxide or similar ligands. The best results are obtained in general for the most stable clusters such as triruthenium, triosmium, tetrarhodium, and tetrairidium dodecacarbonyls. Thus, heterogeneous pyrolysis reactions of metal halides with carbon monoxide in the presence of halide acceptors such as Cu or Zn under relative drastic conditions of temperature and pressure can be used for preparing these types of three and tetranuclear carbonyl clusters ... 

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