Synthesis, Structure, and Reactivity of Mixed-Metal Clusters Bearing η¹-Acetylide Groups, (η⁵-C₅H₅)MFe₂(μ₃-E)₂(CO)₆(η¹-CCPh) (M = Mo or W and E = Se or Te)

Reaction of Fe₃(CO)₉(μ₃-E)₂ (E = Se, Te) with (η⁵-C₅H₅)M(CO)₃(C⋮CPh) (M = Mo, W), in the presence of trimethylamine-N-oxide (TMNO), in acetonitrile solvent at 60 °C yields the novel mixed-metal clusters (η⁵-C₅H₅)MFe₂(μ₃-E)₂(CO)₆(η¹-CCPh) (1, E = Se, M = Mo; 2, E = Se, M = W; 3, E = Te, M = Mo; 4, E = Te, M = W) bearing η¹-acetylide groups. The reaction of 1 or 3 with dicobalt octacarbonyl at room temperature gives the mixed-metal clusters (η⁵-C₅H₅)MoFe₂Co₂(μ₃-E)₂(CO)₉(μ-CCPh) (5, 6). Structures of 1 and 6 have been established crystallographically.