Density functional calculations and Raman spectroscopic data were correlated with the unique catalytic epoxidation activity of peroxomolybdenum complexes [MoO(O 2 ) 2 (O-ER 3 )] (E N, P, As; R n-dodecyl) in a biphasic chloroform ± 1-octene/aqueous hydrogen peroxide system. Crystal structure determinations on [MoO(O 2 ) 2 (OPtBu 3 )(OCMe 2 )] and two complexes containing chelating hemilabile ether ± phosphane oxide and ether ± arsane oxide ligands [MoO(O 2 ) 2 -{iPr 2 E(O)CH 2 CH 2 OCH 3 }] (E P, As) are reported. A mechanistic study with these model complexes reveals the importance of free coordination sites for peroxide activation. Calculations and Raman spectroscopic data indicate the tendency of coordinatively unsaturated species [MoO(O 2 ) 2 (L)] to dimerize in noncoordinating solvents. The catalytic activity in the presence of water as competing ligand could be correlated with the calculated proton affinity of the ligands OER 3 (R N, P, As). Elucidation of the vibrational behavior of the structurally characterized peroxo complexes was supported by normal-coordinate analyses.

Diimido-, Imido(oxo)-, Dioxo-und Imido(alkyliden)-Halbsandwich-Verbindungen über selektive Hydrolyse und α؊H-Abstraktion an Organylkomplexen des sechswertigen Molybdäns und Wolframs

Bis(trimethylsily1) peroxide (BTSP) and tert-butyl hydroper-as oxygen source were achieved with the vanadates oxide (tBuOOH) were activated by various 0x0 and peroxo [VO(OR),] (R = fBu, iPr). Comparative selectivity and rate complexes of molybdenum, tungsten, and vanadium as cata-data for the stoichiometric and catalytic sulfoxidations of SSO lysts for the sulfoxidation of thianthrene 5-oxide (SSO). A mediated by the Mo0,L complex ( L = OPtBu:,, OPnOct3, screening of a number of phosphane oxide and amine oxide ONnBu,, ONnOct,) suggest that the bisperoxo metal comligands revealed that BTSP was most efficiently activated by plex is the active oxygen transfer species. the [MoO5(0PfBu3)] complex. The best results for tBuOOH Clrem.

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