Our density functional theory study of hydroperoxy (OOH) intermediates on various model titanosilicalite (TS-1) Ti centers explores how microstructural aspects of Ti sites effect propylene epoxidation reactivity and shows that Ti sites located adjacent to Si vacancies in the TS-1 lattice are more reactive than fully coordinated Ti sites, which we find do not react at all. We show that propylene...

Effects of high irradiance and moderate heat on photosynthesis of the tree-fern Dicksonia antarctica (Labill., Dicksoniaceae) were examined in a climate chamber under two contrasting irradiance regimes (900 and 170mmol photonsm s) and three sequential temperature treatments (15 C; 35 C; back to 15 C). High irradiance led to decline in predawn quantum yield of photochemistry, Fv/Fm (0.73), maxim...

We have examined various postulated pathways for the catalytic epoxidation of olefins by silver using ab initio quantum mechanical methods to study likely intermediates in this reaction. In particular, we predict preferred binding sites, geometries, vibrational frequencies, and binding energies for 0, O,, Cl, H, OH, and C,H, on a cluster model for Ag aggregates present on supported catalysts. T...

The Fe3O4@SiO2@APTMS@Glu-His@V complex was prepared with modification of iron oxide magnetic nanoparticles with (3-aminopropyl) trimethoxysilane (APTMS) and glutaraldehyde-L-histidine Schiff base followed by complexation with VOSO4. Characterization of the Fe3O4@SiO2@APTMS@Glu-His@V complex was carried out by means of FTIR, XRD, SEM, EDX, TEM, AAS and VSM techniques. It was found that Fe3O4@SiO...

two new heterogenized epoxidation nanocatalysts based on molybdenum and tungsten compounds were prepared withcovalent grafting of mcm-41 with 3-aminoropropyl trimethoxysilane and subsequent reaction with diphenylphosphinobenzaldehyde and complexation with m (mo, w)o2(acac)2. x-ray diffraction and nitrogen sorption analyses revealed the preservation of the textural properties of the support as w...

Supported gold nanoparticles (NPs), which are well-known epoxidation catalysts, were found to be exceptionally active for the selective deoxygenation of epoxides into alkenes using cheap and easily accessible CO and H(2)O as the reductant.

The germene Mes(2)Ge=CR(2) (Mes = 2,4,6-trimethylphenyl, CR(2) = fluorenylidene) reacts with various benzil derivatives to lead to germanium-containing bicyclic epoxides by an unexpected new type of epoxidation reaction.

Catechol-functionalized (salen)Mn complexes can be supported on mesoporous anodized aluminium oxide disks to yield catalytic membranes that are highly active in the enantioselective epoxidation of olefins when being deployed in a forced-through-flow reactor.

A (perarylcyclopentadienyl)molybdenum(VI) dioxo complex is shown to catalyse epoxidation of cyclooctene by t-butylhydroperoxide, but decomposition to a much more active non-cyclopentadienyl containing catalyst occurs as the reaction proceeds.