SS Bond-activation of diorganyl disulfide by anionic [Mn(CO)5]−: crystal structures of [MnII(SC5H4NO)3]− and [(CO)3Mn(μ-SR)3Co(μ-SR)3Mn(CO)3]− (R=C6H4NHCOPh)

The SS bond-activation of diorganyl disulfide by the anionic metal carbonyl fragment [Mn(CO)5]− gives rise to an extensive chemistry. Oxidative decarbonylation addition of 2,2′-dithiobis(pyridine-N-oxide) to [Mn(CO)5]−, followed by chelation and metal-center oxidation, led to the formation of [MnII(SC5H4NO)3]− (1). The effective magnetic moment in solid state by SQUID magnetometer was 5.88 μB for complex 1, which is consistent with the MnII having a high-spin d5 electronic configuration in an octahedral ligand field. The average Mn(II)S, SC and NO bond lengths of 2.581(1), 1.692(4) and 1.326(4) Å, respectively, indicate that the negative charge of the bidentate 1-oxo-2-thiopyridinato [SC5H4NO]− ligand in complex 1 is mainly localized on the oxygen atom. The results are consistent with thiolate-donor [SC5H4NO]− stabilization of the lower oxidation state of manganese (Mn(I)), while the O,S-chelating [SC5H4NO]− ligand enhances the stability of manganese in the higher oxidation state (Mn(II)). Activation of SS bond as well as OH bond of 2,2′-dithiosalicylic acid by [Mn(CO)5]− yielded [(CO)3Mn(μ-SC6H4C(O)O)2Mn(CO)3]2− (4). Oxidative addition of bis(o-benzamidophenyl) disulfide to [Mn(CO)5]− resulted in the formation of cis-[Mn(CO)4(SR)2]− (R=C6H4NHCOPh) which was employed as a chelating metallo ligand to synthesize heterotrinuclear [(CO)3Mn(μ-SR)3Co(μ-SR)3Mn(CO)3]− (8) possessing a homoleptic hexathiolatocobalt(III) core.