Room temperature ring opening of a 1,3-dithiole-2-thione at a dimolybdenum centre

The reaction of [Mo2(CO)4Cp2] (1; Cp=η-C5H5) with 4,5-bis(carbomethoxy)-1,3-dithiole-2-thione at room temperature affords two products, both of which have been crystallographically characterised. In the first, [Mo2{μ-SCS2C2(CO2Me)2}(CO)5Cp2] (2), the Mo≡Mo bond has been completely cleaved and the complex consists of the heterocycle η2-side-bound through the thione function to a CpMo(CO)2 unit, with an additional CpMo(CO)3 group attached to the thione sulfur atom. In the second complex, [Mo2{μ-SCSC(CO2Me)C(CO2Me)S}(CO)3Cp2] (3) the MoMo bond has been retained and partial ring opening of the heterocycle by CS bond cleavage has occurred, the latter being bonded as a thiolate ligand to one molybdenum and through the thione group to both metals.