Synthesis and Spectroscopic Characterization of (CO)6Fe2 {μ-EC(H)C(H)E‘} (E ≠ E‘; E, E‘ = S, Se, Te) and (CO)6Fe2{μ-TeC(H)C(H)Te}. Structural Characterization of (CO)6Fe2{μ-SC(Ph)C(H)Se} and (CO)6Fe2{μ-SC(H)C(Ph)Te}

When acetylene gas was bubbled through methanol solutions containing the mixed-chalcogenide compounds (CO)6Fe2 (μ-EE‘) (E ≠ E‘; E, E‘ = S, Se, Te), the acetylene adducts (CO)6Fe2{μ-EC(H)C(H)E‘} (1, 52%, E, E‘ = S, Se; 2, 46%, E, E‘ = S, Te; 3, 38%, E, E‘ = Se, Te) were obtained. In addition, trace amounts of the homochalcogenide derivatives (CO)6Fe2{μ-EC(H)C(H)E} (E = S, Se, Te) were also obtained. The Te2 compound (CO)6Fe2{μ-TeC(H)C(H)Te} (4) was obtained in 32% yield from the reaction of (CO)6Fe2(μ-Te2) with acetylene. Compounds 1−4 were characterized by IR and 1H, 13C, 77Se, and 125Te NMR spectroscopy. Crystallographic analysis of the phenylacetylene adducts (CO)6Fe2{μ-SC(Ph)C(H)Se} (5) and (CO)6Fe2{μ-SC(H)C(Ph)Te} (6) were carried out. The structures of both 5 and 6 can be described as Fe2SE (E = Se, Te) tetrahedral butterfly cores containing the phenylacetylene as a bridge between the two wingtip chalcogen atoms, with three terminally bonded carbonyl groups on each Fe atom.