Binuclear Iron(I), Ruthenium(I), and Osmium(I) Hexacarbonyl Complexes Containing a Bridging Benzene-1,2-dithiolate Ligand. Synthesis, X-ray Structures, Protonation Reactions, and EHMO Calculations

The dithiolate-bridged complexes [M2(μ-bdt)(CO)6] (M = Fe (1), Ru (2), Os (3); bdt = benzene-1,2-dithiolate) have been prepared. X-ray diffraction studies have revealed that although the three compounds have analogous molecular structures their crystal structures are different as a result of different molecular packings. Complex 1 does not react with tetrafluoroboric acid in 1,2-dichloroethane, while compounds 2 and 3, under the same conditions, undergo protonation at the metal atoms to give the cationic hydrido derivatives [M2(μ-H)(μ-bdt)(CO)6][BF4] (M = Ru, Os). EHMO calculations have been used to rationalize the results of the protonation reactions.