X-ray-determined structure of the technetium com­plex [Tc(2)(μ-CO)(2)(NC(5)H(5))(2)(CO)(6)] revisited: [Tc(2)(μ-OMe)(2)(NC(5)H(5))(2)(CO)(6)] as the correct formulation

Some of us reported previously the structure of di-μ-carbonyl-bis­[tricarbon­yl(pyridine)­technetium], [Tc(2)(μ-CO)(2)(C(5)H(5)N)(2)(CO)(6)], as the main product of the reaction of [Tc(2)(CO)(10)] with pyridine at room temperature, using the reagent itself as solvent [Zuhayra et al. (2008). Inorg. Chem. 47, 10177–10182]. On the basis of an X-ray analysis of the product, a mol­ecular structure was proposed with two bridging carbonyls displaying very unusual geometrical features, not explained at the time. Subsequent chemical considerations, coupled with density functional theory (DFT) calculations, prompted us to revise the original structure determination. Using the original raw diffraction data, we have now per­form­ed new refinements to show that the previously proposed ‘bridging car­bon­yls’ actually correspond to bridging methoxide groups, and that the crystals analyzed at the time therefore would correspond to the com­plex di-μ-methoxido-bis­[tricarbon­yl(pyridine)­technetium], syn-[Tc(2)(μ-OMe)(2)(NC(5)H(5))(2)(CO)(6)]. This methoxide-bridged com­plex likely was a minor side product formed along with the main product in the above reaction, perhaps due to the presence of trace amounts of methanol and air in the reaction mixture.