New Disulfido Molybdenum-Manganese Complexes Exhibit Facile Addition of Small Molecules to the Sulfur Atoms

The reaction of M...) (1) with [CpMo(CO)3]2 (CP = CsHs) and [Cp*Mo(CO)3]2 (Cp* = C5(CH3)5) yielded the new mixed-metal disulfide complexes CpMoMn(CO)5(-S2) (2) and Cp*MoMn(CO)5((mu)-S2) (3) by a metal-metal exchange reaction. Compounds 2 and 3 both contain a bridging disulfido ligand lying perpendicular to the Mo-Mn bond. The bond distances are Mo-Mn = 2.8421(10) and 2.8914(5) A and S-S = 2.042(2) and 1.9973(10) A for 2 and 3, respectively. A tetranuclear metal side product CpMoMn3(CO)i3(3-S)(4-S) (4) was also isolated from the reaction of 1 with [CpMo(CO)3]2. Compounds 2 and 3 react with CO to yield the dithiocarbonato complexes CpMoMn(CO)5-SC(=0)S] (5) and Cp*MoMn(CO)5-SC(=0)S] (6) by insertion of CO into the S-S bond. Similarly, tertbutylisocyanide was inserted into the S-S bond of 2 and 3 to yield the complexes CpMoMn(CO)5-S(C=NB)S] (7) and Cp*MoMn(CO)5-S(C=NBuS] (8), respectively. Ethylene and dimethylacetylene dicarboxylate also inserted into the S-S bond of 2 and 3 at room temperature to yield the ethanedithiolato ligand bridged complexes CpMoMn(CO)5-SCH2CH2S) (9), Cp*MoMn(CO)5(SCH2CH2S) (10), CpMoMn(CO)5[-SC(C02Me)=C(C02Me)S] (11), and Cp*MoMn(CO)5l-SC(C02Me)=C(C02Me)S] (12). Allene was found to insert into the S-S bond of 2 by using one of its two double bonds to yield the complex CpMoMn(CO)5-SCH2C(=CH2)S] (13). The molecular structures of the new complexes 2-7 and 9-13 were established by single-crystal X-ray diffraction analyses.