Synthesis and Structural Characterization of Molybdenum(VI) and Iron(II) Coordination Compounds with S‑Alkyl‑N‑methyl‑S‑(2-pyridyl)sulfoximines and Catalytic Epoxidation Activity of the Molybdenum Complexes

Coordination compounds oxido­(diperoxido)­(S-butyl-N-methyl-S-(2-pyridyl)­sulfoximine)­molybdenum­(VI), [MoO­(O2)2{SO­(NMe)nBu­(NC5H4)}] (5c), and bis­{(dichlorido)­(N,S-dimethyl-2-pyridylsulfoximine)­iron­(II)}, tetrahydrofuran solvate (1:1) (6), [FeCl2{SO­(NMe)­Me­(NC5H4)}]2·THF are prepared from the free ligand 4 and molybdenum­(VI) oxidediperoxide­(dihydrate) and iron dichloride, respectively. The crystal structures reveal a trigonal bipyramid with the pyridine ring and the single oxygen on molybdenum in a trans arrangement for 5c and a planar μ2-Cl2Fe2 ring with trans-oriented exocyclic Cl atoms for 6 whereas the structures of the N,N-dicoordinated ligands are only little effected by the metals. Coordination compounds (5) efficiently catalyze the epoxidation of cyclooctene or of monosubstituted alkenes by tert-butyl hydroperoxide.