Synthesis and properties of oligomers of iron–manganese carbonyl complexes with bridging disulfido ligands

Abstract

The reactions of activated CpFeMn(CO) 7 1a and Cp*FeMn(CO) 7 1b, Cp=C 5Me 5 with thiirane yielded the new dimeric mixed metal disulfido complexes: [CpFeMn(CO) 5(μ 3-S 2)] 2 ( 2) and [Cp*FeMn(CO) 5(μ 3-S 2)] 2 ( 3). Compounds 2 and 3 both contain two triply bridging disulfido ligands. When heated at 40 °C, compound 2 was transformed into a trimeric compound Cp 3Fe 3Mn 3(CO) 15(μ 3-S 2)(μ 4-S 2) 2, 4. Compound 4 contains three disulfido ligands, each of which has a different bridging coordination mode in the six atom metal cluster. There are three inequivalent CpFe(CO) 2 groupings linked to a central Mn 3(S 2) 3 core by the disulfido ligands. In solution, compound 4 exhibits a dynamical intramolecular exchange process that interconverts two of the three CpFe(CO) 2 groups on the NMR timescale.