A heterogeneous olefin epoxidation catalyst containing both V and Ti in the active site was prepared by sequential non-hydrolytic grafting. The silica was exposed first to VO(OPr)3 vapor followed by Ti(O Pr)4 vapor. Formation of propene is evidence for the creation of Ti-O-V linkages on the surface. Upon metathesis of the 2-propoxide ligands with BuOOH, the catalyst becomes active for the gas p...

A heterogeneous catalyst containing manganese Schiff base complex (derived from 2,4-dihydroxybenzadehyde and 1,2-phenylenediamine) is produced by covalent anchoring in MCM-41 matrix. The synthesized catalyst was characterized by X-ray diffraction pattern (XRD), inductivity coupled plasma (ICP), Fourier transform infrared (FT-IR) spectroscopy, N2 sorbtion-desorbtion isotherm and by tr...

The surface of magnetite nanoparticles as nano-sized solid support was modified with a molybdenum-Schiff base complex to prepare an easily separable heterogeneous catalyst for the epoxidation of olefins. Characterization techniques such as Fourier transform infrared and inductively coupled plasma optical emission spectroscopies, X-ray diffraction, vibrating sample magnetometry, scanning, an...

A new microporous metal-organic framework compound featuring chiral (salen)Mn struts is highly effective as an asymmetric catalyst for olefin epoxidation, yielding enantiomeric excesses that rival those of the free molecular analogue. Framework confinement of the manganese salen entity enhances catalyst stability, imparts substrate size selectivity, and permits catalyst separation and reuse.

Oxidation of functioning copper has restricted its applicability as a catalyst for commercially important epoxidation of propylene to form propylene oxide. Here, we report that steady-state selectivity in propylene epoxidation on copper (Cu) nanoparticles increases sharply when the catalyst is illuminated with visible light. The selectivity increase is accompanied by light-induced reduction of ...

The oxidation of copper catalysts during ethylene epoxidation was characterized using in situ photoemission spectroscopy and electron microscopy. Gas chromatography, proton-transfer reaction mass spectrometry and electron-ionization mass spectrometry were used to characterize the catalytic properties of the oxidized copper. We find that copper corrodes during epoxidation in a 1 : 1 mixture of o...

cis-polybutadiene was functionalized using in–situ generated dmd as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (ptc). the epoxidation process was investigated by 1hnmr spectroscopy. 1hnmr spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. various factors such as reaction temperature, reaction time and the concentr...

Epoxides are an important class of industrial chemicals that have been used as chemical intermediates. Catalytic epoxidation of olefins affords an interesting production technology. We found a widely usable green route to the production of epoxides: A silicotungstate compound, [gamma-SiW10O34(H2O)2]4-, is synthesized by protonation of a divacant, lacunary, Keggin-type polyoxometalate of [gamma-...

Cis-polybutadiene was functionalized using in–situ generated DMD as oxidant and tetra-n-butyl ammonium bromide as phase transfer catalyst (PTC). The epoxidation process was investigated by 1HNMR spectroscopy. 1HNMR spectrum analysis of products confirms the absence of ring opening side products in epoxidation reaction. Various factors such as reaction temperature, reaction time and the concentr...

Polyoxomolybdates were generated in situ by treating a carboxylic acid-functionalized ionic liquid with an aqueous solution of sodium molybdate. This reaction mixture was applied in the catalytic epoxidation of olefins using hydrogen peroxide as oxidant. The influence of acid and catalyst concentration as well as of the reaction temperature was investigated. The system showed a good performance...