Introduction: Anomeric effect has found its influential position in the field of chemistry and it can be defined as stereoelectronic stabilizing effect that favor the placement of electronegative substituents in the axial, rather than equatorial, position in a pyranoid ring system at C1 [1].

Stereoelectronic effects is a bridge between structure and reactivity [1]. Anomeric effect plays an important role in the domain of stereoelectronic interaction and can be used for description of several unusual phenomena. Intramolecular negative hyperconjugation is also known as anomeric effect [2]. In anomeric effect, both donor (lone pairs) and acceptor groups (electronegative elements) coexist in a proper molecule. This coexistence causes the acceptor groups to prefer the axial position in anomeric position (Scheme 1) [1, 3-15]...

The bubble effectiveness in liquid phase cylohexane non-catalytic oxidation process is discussed in this paper. Then the bubble effectiveness and a new proposed kinetic model are used in the mathematical model of the industrial reactor for the cyclohexane non-catalytic oxidation process. Furthermore, simulation and optimization based on this reactor model are carried out. The results of simulation show that the reactor model using the concept of bubble effectiveness agrees better with the plant data, and the results of optimization are much better than the present industrial production level, which will help to improve the operation of the reactor section and design of new installations.

By coupling of Fe2O3@SiO2 particles with metal organic framework (MOF) the magnetic MOF structure was fabricated. Precipitation and hydrothermal methods were applied for the synthesis of core and MOF. Silver nanoparticles were deposited on nickel based metal organic framework surface and magnetic Fe2O3@SiO2@MOF@Ag was obtained. Because of strong coupling between silver nanoparticles and metal organic framework, the catalyst demonstrated high catalytic activity and selectivity in aerobic oxidation of alkenes under mild conditions. The nanostructure, exhibited high catalytic activity. Alkenes oxides (epoxy alkanes) were the main products with more than 89. 9% selectivity.

Reaction of gas-phase oxidation of 4-methylpyridine on individual V2O5, binary and ternary vanadium-oxide catalysts was studied. These catalysts were modified by additives of SnO2 and TiO2. It was found that modifying V2O5 leads to increase in the activity of binary contacts. Upon transition from binary V2O5-SnO2 and V2O5-TiO2 catalysts to the ternary system of V2O5-TiO2-SnO2, a higher increase in activity is observed. This extension in activity leads to increase conversion of initial substance and shifting the maximum yield of intermediate pyridine-4-carbaldehyde and isonicotinic acid to the low-temperature area. To research the mechanism of promotion, we used the quantum chemical method of Density Functional Theory. It was found that the promoting effect of SnO2 and TiO2 was caused by increasing a proton affinity of vanadyl oxygen (PAV=O). Upon transition from binary clusters to the ternary system of V2O5-TiO2-SnO2 the synergism effect is observed. It is shown that by transfer of a proton to vanadyl oxygen and formation of a new O− H bond the energy is emitted. This energy compensates a heterolytic C− H bond cleavage. It was found that the promoting effect of SnO2 and TiO2 causes the decrease of deprotonation enthalpy of the methyl substituent of the chemisorbed substrate. The results of the calculations agree with the experimental data on the influence of oxide modifiers on activity and selectivity of the studied catalysts in 4-methylpyridine oxidation.

Manganese-based octahedral molecular sieves of the type K-OMS-2 (cryptomelane structure) were prepared via reflux method by synproportionation of KMnO4 and Mn2+ in acidic aqueous suspension. For this method, different manganese anions (sulphate, chloride and acetate) were used, which exert a strong influence on the prepared materials. Several techniques such as X-ray diffraction, Fourier transformer infrared, Raman spectroscopy, transmission electron microscopy, differential and gravimetric thermal analysis and H2-temperature programmed reduction were used to characterize the prepared samples. The results revealed that the prepared samples were mainly pure mono-phase cryptomelane materials. The obtained K-OMS-2 material on using the sulphate anion has more available lattice oxygen as compared to that prepared by the other anions. The catalytic activity of the prepared samples was tested towards the oxidative dehydrogenation of cyclohexane. Over the K-OMS-2RS sample, cyclohexane conversion was significantly higher than the other prepared samples.

The partial oxidation of natural gas with oxygen at different independent variables such as fuel equivalence ratios from 2 to 4, preheat temperatures of feed gas streams up to 200ºC and space velocities from 40 to 100hr-1 was studied. Experiments were carried out using a bench-scale syngas generator mainly consisted of preheats sections, a water cooled swirling jet burner, a combustion chamber and a water quenching chamber. Evaluation parameters were selected to be H2/CO ratio, CO selectivity, natural gas conversion and syngas yield. Results show that the fuel equivalence ratio is the most important factor for syngas production. Preheating the feed gas streams was generally made better conditions and by increasing the space velocity the better operating conditions achieved. The operation of the system showed successful obtaining of syngas from natural gas using noncatalytic partial oxidation.