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}

Abstract

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.