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

The reaction of Mn<sub>2</sub>(CO)<sub>7</sub>(μ-S<sub>2</sub>) (<b>1</b>) with [CpMo(CO)<sub>3</sub>]<sub>2</sub> (Cp = C<sub>5</sub>H<sub>5</sub>) and [Cp*Mo(CO)<sub>3</sub>]<sub>2</sub> (Cp* = C<sub>5</sub>(CH<sub>3</sub>)<sub>5</sub>) yielded the new mixed-metal disulfide complexes CpMoMn(CO)<sub>5</sub>(μ-S<sub>2</sub>) (<b>2</b>) and Cp*MoMn(CO)<sub>5</sub>(μ-S<sub>2</sub>) (<b>3</b>) by a metal−metal exchange reaction. Compounds <b>2</b> and <b>3</b> 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) Å and S−S = 2.042(2) and 1.9973(10) Å for <b>2</b> and <b>3</b>, respectively. A tetranuclear metal side product CpMoMn<sub>3</sub>(CO)<sub>13</sub>(μ<sub>3</sub>-S)(μ<sub>4</sub>-S) (<b>4</b>) was also isolated from the reaction of <b>1</b> with [CpMo(CO)<sub>3</sub>]<sub>2</sub>. Compounds <b>2</b> and <b>3</b> react with CO to yield the dithiocarbonato complexes CpMoMn(CO)<sub>5</sub>[μ-SC(O)S] (<b>5</b>) and Cp*MoMn(CO)<sub>5</sub>[μ-SC(O)S] (<b>6</b>) by insertion of CO into the S−S bond. Similarly, <i>tert</i>-butylisocyanide was inserted into the S−S bond of <b>2</b> and <b>3 </b>to yield the complexes CpMoMn(CO)<sub>5</sub>[μ-S(CNBu<sup>t</sup>)S] (<b>7</b>) and Cp*MoMn(CO)<sub>5</sub>[μ-S(CNBu<sup>t</sup>)S] (<b>8</b>), respectively. Ethylene and dimethylacetylene dicarboxylate also inserted into the S−S bond of <b>2</b> and <b>3</b> at room temperature to yield the ethanedithiolato ligand bridged complexes CpMoMn(CO)<sub>5</sub>(μ-SCH<sub>2</sub>CH<sub>2</sub>S) (<b>9</b>), Cp*MoMn(CO)<sub>5</sub>(μ-SCH<sub>2</sub>CH<sub>2</sub>S) (<b>10</b>), CpMoMn(CO)<sub>5</sub>[μ-SC(CO<sub>2</sub>Me)C(CO<sub>2</sub>Me)S] (<b>11</b>), and Cp*MoMn(CO)<sub>5</sub>[μ-SC(CO<sub>2</sub>Me)C(CO<sub>2</sub>Me)S] (<b>12</b>). Allene was found to insert into the S−S bond of <b>2</b> by using one of its two double bonds to yield the complex CpMoMn(CO)<sub>5</sub>[μ-SCH<sub>2</sub>C(CH<sub>2</sub>)S] (<b>13</b>). The molecular structures of the new complexes <b>2</b>−<b>7</b> and <b>9</b>−<b>13</b> were established by single-crystal X-ray diffraction analyses.