Effect of Chlorine and Nitrosyl Chloride on Nitrogen(II) Oxide Oxidation into Nitrogen(IV) Oxide

The effect of chlorine and nitrosyl chloride impurities on the regeneration of nitrogen(IV) oxide—oxidizing agent in oxychlorination of hydrocarbons—was studied at two temperatures. An assumption is made that the process occurs by radical-chain mechanism and involves chlorine oxides.     

Kinetics of Low-Temperature Oxidative Chlorination of Benzene in Aqueous Acetic Acid

The kinetics of chlorination of benzene with a mixture of sodium peroxide with hydrochloric acid in aqueous acetic acid at 298 K was studied. The chlorination rate is the highest when the AcOH concentration in the binary solvent is 49.4-40.6 mol % and the ratio of the initial cocentrations of water and sodium peroxide, 18.5–20.2. The linear dependences of logk _app on the AcOH concentration and [H₂O]₀/[Na₂O₂]₀ ratio were obtained.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 792–794.Original Russian Text Copyright © 2005 by Rudakova, Erykalov.     

Oxidative Transformations of Phenylacetylene on a Manganese(IV) Oxide Adsorbent-Catalyst

It is shown by IR spectroscopy and thermally programmed surface reactions that the complete oxidation of phenylacetylene on hydrated manganese dioxide in an adsorption catalytic regime occurs via dissociation of the CC bond (during chemisorption) with the formation of formate and benzoate on the surface.     

Nitration of Alkenes and Oxiranes with Nitrogen(IV) Oxide in Liquid and Supercritical Carbon Dioxide Media

Doklady Chemistry - For the first time the reactions of radical nitration of alkenes and oxiranes with nitrogen dioxide in the liquid and supercritical carbon dioxide (sc-CO2) media were carried...     

Oxidative Rearrangement via Oxycerication with Ce(IV) Salt

α-Arylpropanoic acids are pharmaceutically interesting compounds, some of them exhibit anti-flammatory and analgestic activities1. Even the enormous progress made in the synthesis of α-arylpropanoic acids by 1,2-aryl rearrangement of arylpropanone using thalium (III) nitrate1,2, silver (I) compounds,3,4 lead (IV) acetate5,6 and iodinate7 during the last decades. The route is, however, unsuitable for the preparation of pharmaceutical products (Naproxen, Ibuprofen and so on) because of the …     

Oxidative breakdown of polymeric plutonium(IV) hydroxide by cerium(IV)

The breakdown of polymeric plutonium(IV) hydroxide (plutonium colloid) by cerium(IV) has been studied spectrophotometrically by monitoring the formation of plutonium(VI). Reaction rate variations were studied with changes in cerium(IV), acid and plutonium colloid concentrations. A reaction mechanism involving the formation of [Ce₂O(OH)₂]⁴⁺ and its reaction with the polymer surface to produce two plutonium(V) ions is postulated to explain the observed kinetic data, in particular the maximum in the reaction rate at around 0.3 M nitric acid.     

Oxidative Hydroxylation of Benzene and Toluene by Nitrous Oxide Over Fe-Containing ZSM-5 Zeolites

The gas-phase partial oxidation of benzene and toluene to phenol and to cresols over Fe-containing ZSM-5 zeolites prepared by various methods was studied using N₂O as oxidant. Over FeZSM-5 synthesized by either isomorphous substitution or ion exchange the phenol selectivity reached nearly 100% at 573 K, however, only 25-30% cresol (mainly p-cresol) selectivity was observed in the oxidation of toluene because of the formation of benzaldehyde and benzoic acid in the fast oxidation of the methyl group.     

The Isoelectric Point of an Exotic Oxide: Tellurium (IV) Oxide

The pH-dependent surface charging of tellurium (IV) oxide has been studied. The isoelectric point (IEP) of tellurium (IV) oxide was determined by microelectrophoresis in various 1-1 electrolytes over a concentration range of 0.001–0.1 M. In all electrolytes studied and irrespective of their concentration the zeta potential of TeO₂ was negative over the pH range 3–12. In other words the IEP of TeO₂ is at pH below 3 (if any). TeO₂ specifically adsorbs ionic surfactants, and their presence strongly affects the zeta potential. In contrast the effect of multivalent inorganic ions on the zeta potential of TeO₂ is rather insignificant (no shift in the IEP). In this respect TeO₂ is very different from metal oxides.     

Bioanalysis by Immobilization of Antibodies on Hafnium(IV) Oxide with 3-Aminopropyltriethoxysilane

Self-assembled monolayers of 3-aminopropyltriethoxysilane (APTES) are commonly used to promote adhesion between substrates and organic or metallic materials with applications ranging from advanced composites to biomolecular lab-on-a-chip devices. In this work, the silanization on hafnium oxide (HfO₂) films is reported. The layers of HfO₂ were deposited on Si (001) substrates by atomic layer deposition. The grown HfO₂ films were modified in accordance with three main steps: oxidation, silanization, and cross-linking of the APTES monolayer using glutaraldehyde as cross-linking agent. Microscopic features were characterized by atomic force microscopy. Further, both bovine serum albumin and antibovine serum albumin agents were deposited on the samples to test their potential use as the immunosensor.     

Kinetics of Starch Oxidation in the System Nitrogen(IV) Oxide-Tetrachloromethane

Kinetics of potato starch oxidation by dinitrogen tetroxide in CCl₄ was studied as influenced by the oxidant concentration, temperature, and starch to N₂O₄ ratio. The starch oxidation products were analyzed by IR spectroscopy.     

Catalytic Oxidation of Triphenylphosphine with Nitrogen(I) Oxide in the Presence of Tetrakis(tert-butyl)phthalocyanine Complexes

Russian Journal of General Chemistry -     

苯和1-辛烯对Ce(IV)Y分子筛选择性吸附脱硫的影响

选取苯和1-辛烯作为模拟汽油中的芳烃和烯烃, 分别研究它们对Ce(IV)Y分子筛选择性吸附脱硫的影响. 结果表明, 吸附剂的选择性吸附脱硫性能随着模拟油中苯和1-辛烯含量的增加而显著降低. 借助傅立叶变换红外光谱(FT-IR)、紫外漫反射光谱(UV-DRS)技术研究发现, Ce(IV)Y分子筛对苯和1-辛烯的吸附模式及影响脱硫的机理是不同的. Ce(IV)Y分子筛阳离子和苯形成π络合作用, 作用力较弱, 容易脱附; 而与1-辛烯的双键发生σ-π络合, 不容易脱附. 在Ce(IV)Y分子筛选择性吸附含苯模拟油中的硫化物时, 由于苯的存在, 苯和噻吩在分子筛表面存在严重竞争吸附, 影响了吸附剂的选择性脱硫. 而在含1-辛烯的模拟油中, 由于1-辛烯直接和分子筛发生强相互作用, 占据了吸附剂的活性位, 导致Ce(IV)Y分子筛的脱硫性能显著降低.     

Oxidative desulfurization of dibenzothiophene with hydrogen peroxide catalyzed by selenium(IV)-containing peroxotungstate

With stoichiometric H(2)O(2) as oxidant, dibenzothiophene (DBT) is oxidized to its corresponding sulfone with high efficiency, catalyzed by a sub-valence heteronuclear peroxotungstate, [C(18)H(37)N(CH(3))(3)](4)[H(2)Se(IV)(3)W(6)O(34)], under mild biphase conditions and the catalyst shows remarkable selectivity of catalytic oxidation towards DBT, cinnamyl alcohol and quinoline.     

Selenium(IV) Oxide Catalyzed Oxidation of Aldehydes to Carboxylic Acids with Hydrogen Peroxide

A convenient method for oxidative transformation of aromatic, hetero-aromatic and aliphatic aldehydes into carboxylic acids is presented. It is based on the oxidation of aldehydes in THF using 30% hydrogen peroxide in the presence of 5 molar % of selenium(IV) oxide. The scope and limitation of the method are discussed.     

Thermodynamic and Kinetic Parameters of Cerium(IV) Complexes with Some Dicarboxylic Acids

The thermodynamic and kinetic parameters of the cerium(IV) complexes formed in the initial stage of oxidation of dicarboxylic acids (H₂L), like pentanedioic, butanedioic, propanedioic, and ethanedioic acids, by cerium(IV) sulfate were studied by the spectrophotometric and pH-potentiometric methods with the aid of integral kinetic methods at an ionic strength I = 2 mol/L within the pH range of–0.3–1.6 in a sulfuric acid medium and at temperature of 293.15 K. The composition of these complexes, the form of organic ligand existence therein, the thermodynamic parameters of their formation, and the kinetic parameters of their intramolecular redox decomposition were determined. Linear correlations between the found thermodynamic and kinetic parameters of the examined complexes [CeOHL]⁺ were obtained. The rate equation of the redox process occurring in the systems Ce⁴⁺–H₂L was established and the corresponding reaction model was considered.     

Specific Interaction of Nitrogen(II) Oxide with Sublimed Layers of Iron(II) meso-Mono-4-Pyridyltriphenylporphyrinate

IR studies revealed that unlike iron(II) meso-tetraphenylporphyrinate (FeTPP), NO interacts with sublimed layers of iron(II) meso-mono-4-pyridyltriphenylporphyrinate (FeM4PyTPP) to give two types of nitrosyl complexes. The stretching vibration frequency of the coordinated NO in one of them is close to that observed in the nitrosyl FeTPP complex, while in the other complex, it is 28 cm^–1lower. The spectral differences observed upon coordination of NO by two porphyrins with similar structures are explained by the fact that in the sublimed FeM4PyTPP layers, the structures are formed in which the pyridyl group of one molecule is coordinated by the metal ion of the neighboring molecule, while the nitrosyl ligand occupies the sixth coordination site. The thermal stability of the complexes formed, the effect of the extra ligands on the layer structure, and the mechanism of the nitrosyl ligand exchange for its isotopic analog ¹⁵NO are discussed.     

Remediation of Wastewater with Ultraviolet Irradiation Using a Novel Titanium (IV) Oxide Photocatalyst

Photocatalysis has become common and nanomaterials having photocatalytic functions have been widely characterized. At present, among the many candidates for photocatalysis, TiO₂ is almost the only material suitable for industrial use. In this paper, we present a TiO₂ synthesis starting from Ti sheets put in contact with a mixture of 0.1 N NaOH and acetone for 72?hours under ambient conditions. The obtained sheets were washed with distilled water and ethanol, and the surface was analyzed for its structural and morphological properties. Thus, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) investigations indicated the formation of TiO₂ on the edges of nanometer circles on the surface of the Ti sheets. For characterizing the photocatalytic capacity for wastewater treatment, Ti sheets with TiO₂ on the surface contacted with methylene blue solutions at room temperature under ultraviolet light. The degradation of the methylene blue concentration was measured by ultraviolet–visible spectroscopy, demonstrating 99.94% efficiency for wastewater treatment using the obtained material.