Disulfides of manganese carbonyl.: Synthesis of Mn2(CO)7(μ-S2) and its reactions with tertiary phosphines and arsines

The reaction of Mn-2(CO)(9)(NCMe) with thiirane yielded the sulfidomanganese carbonyl compounds Mn-2(CO)(7)(mu-S-2), 2, Mn-4(CO)(15)(mu(3)-S-2)(mu(4)-S-2), 3, and Mn-4(CO)(14)(NCMe)(mu(3)-S-2) (mu(4)-S-2), 4, by transfer of sulfur from the thiirane to the manganese complex. Compound 3 was obtained in better yield from the reaction of 2 with CO, and compound 4 is obtained from the reaction of 2 with NCMe. The reaction of 2 with PMe2Ph yielded the tetramanganese disulfide Mn-4(CO)(15)(PMe2Ph)(2)(mu(3)-S)(2), 5, and S=PMe2Ph. The reaction of 5 with PMe2Ph yielded Mn-4(CO)(14)(PMe2Ph)(3)(mu(3)-S)(2), 6, by ligand substitution. The reaction of 2 with AsMe2Ph yielded the new complexes Mn4(CO)14(AsMe2Ph)2(u3-S2)2, 7, Mn-4(CO)(14)(AsMe2Ph)(mu(3)-S-2)(mu(4)-S-2), 8, Mn-6(CO)(20)(AsMe2Ph)(2)(mu(4)-S-2)(3), 9, and Mn-2(CO)(6)(AsMe2Ph)(mu-S-2)(2) 10. Reaction of 2 with AsPh3 yielded the monosubstitution derivative Mn-2(CO)(6)(AsPh3)(mu-S-2), 11. Reaction of 7 with PMe2Ph yielded Mn-4(CO)(15)(AsMe2Ph)(2)(mu(3)-S)(2), 12. The phosphine analogue of 7, Mn-4(CO)(14)(PMe2Ph)(2)(mu(3)-S-2)(2), 13, was prepared from the reaction of Mn2(CO)9(PMe2Ph) with Me3NO and thiirane. Compounds 2-9 and 11-13 were characterized by single-crystal X-ray diffraction. Compound 2 contains a disulfido ligand that bridges two Mn(CO)(3) groups that are joined by a Mn-Mn single bond, 2.6745(5) Angstrom in length. A carbonyl ligand bridges the Mn-Mn bond. Compounds 3 and 4 contain four manganese atoms with one triply bridging and one quadruply bridging disulfido ligand. Compounds 5 and 6 contain four manganese atoms with two triply bridging sulfido ligands. Compound 9 contains three quadruply bridging disulfido ligands imbedded in a cluster of six manganese atoms.