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(O-2)(2){SO(NMe)Bu-n(NC5H4)}] (5c), and bis-{(dichlorido)(N,S-dimethyl-2-pyridylsulfoximine)iron(II)}, tetrahydrofuran solvate (1:1) (6), [FeCl2{SO(NMe)Me(NC5H4)}](2)center dot 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 mu(2)-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.