3675-13-6Relevant academic research and scientific papers
Comparative studies of the photocatalytic and microwave -assisted degradation of alizarin red using ZnO/poly(1- naphthylamine) nanohybrids
Riaz, Ufana,Ashraf,Budhiraja, Vaibhav,Aleem, Sadaf,Kashyap, Jyoti
, p. 259 - 267 (2016/01/20)
Semiconductors such as ZnO and TiO2 have been extensively utilized in the photocatalytic degradation of dyes. However till date, no study has been reported to compare the catalytic efficiency of such organic-inorganic hybrids under UV light and microwave irradiation separately. The present work reports the synthesis of poly(1-naphthylamine)/ZnO nanohybrids. The structure and morphology of the synthesized nanocomposites were characterized using FT-IR, UV, XRD, TEM and Cyclic voltammetry analyses. The dye degradation studies were done separately in a photochemical reactor and in laboratory microwave oven and the fragments were identified using LC-MS technique. Results showed that under microwave irradiation, the efficiency of ZnO/PNA as catalyst was higher as compared to UV irradiation. Higher extent of ?OH radical generation was confirmed in microwave as compared to UV irradiation which was found to be responsible for the high rate of degradation of dye solution. A plausible degradation pathway was proposed.
Formation of phenol and carbonyls from the atmospheric reaction of OH radicals with benzene
Berndt, Torsten,Boege, Olaf
, p. 1205 - 1214 (2008/02/07)
The gas-phase reaction of OH radicals with benzene has been studied in a flow tube operated at 295 ± 2 K and 950 mbar of synthetic air or O 2. Ozonolysis of tetramethylethylene (dark reaction) with a measured OH radical yield of 0.92 ± 0.08 or photolysis of methyl nitrite in the presence of NO served as the OH sources. For investigations in the presence of NOx, the conditions were chosen so that more than 95% of the OH/benzene adduct reacted with O2 even for the highest NO2 concentration occurring in the experiment. In the absence of NOx, a phenol yield from the reaction of OH radicals with benzene of 0.61 ± 0.07 was measured by means of long-path FT-IR and UV spectroscopy over a wide range of experimental conditions. This yield was confirmed by measurements performed in the presence of NOx. Detected carbonyls were glyoxal, cis-butenedial and trans-butenedial with formation yields of 0.29 ± 0.10, 0.08 ± 0.03 and 0.023 ± 0.007, respectively, measured in synthetic air and in the presence of NOx. There was no significant difference in the product yields applying both experimental approaches for OH generation (dark reaction or photolysis). Nitrobenzene and o-nitrophenol were detected in traces. The yield of nitrobenzene increased with increasing NO x resulting in a maximum formation yield of 0.007. The detected products in the presence of NOx account for ～78% of the reacted carbon. Butenedial yields from benzene degradation are reported for the first time. In the absence of NOx, glyoxal, cis-butenedial and trans-butenedial were also detected, but with distinctly lower yields compared to the experiments with NOx. the Owner Societies 2006.
Catalytic oxidation of furan and hydrofuran compounds. 6. Oxidation of furan by hydrogen peroxide in the presence of vanadium compounds under the conditions of phase-transfer catalysis
Poskonin,Badovskaya,Povarova,Ponomarenko
, p. 1143 - 1149 (2007/10/03)
Oxidation of furan in system containing hydrogen peroxide, vanadium compound, chlorinated hydrocarbon, water, and phase-transfer catalyst was studied for the first time. In addition to the main product of this process - cis-β-formylacrylic acid - the form
Atmospheric chemistry of benzene oxide/oxepin
Klotz, Bjoern,Barnes, Ian,Becker, Karl H.,Golding, Bernard T.
, p. 1507 - 1516 (2007/10/03)
The atmospheric chemistry of benzene oxide/oxepin, a possible intermediate in the atmospheric oxidation of aromatic hydrocarbons, has been investigated in a large volume photoreactor at 298 K and atmospheric pressure using in situ FTIR spectroscopy for the analysis. Rate coefficients of (10.0 ± 0.4) × 10-11 and (9.2 ± 0.3) × 10-12 cm3 molecule-1 s-1 have been determined for the reaction of benzene oxide/oxepin with OH and NO3 radicals, respectively. Reaction with OH radicals produces almost exclusively the (E,Z)- and (E,E)-isomers of hexa-2,4-dienedial, whereas reaction with NO3 produces (Z,Z)-hexa-2,4-dienedial and unidentified organic nitrates. Phenol has been observed as a major product of the thermal decomposition, visible and UV photolysis of benzene oxide/oxepin. The results are discussed in conjunction with the oxidation mechanisms of aromatic hydrocarbons. The major atmospheric sinks of benzene oxide/oxepin will be reaction with OH radicals and photolysis and, under smog chamber conditions with high NO2 concentrations, also reaction with NO3.
Reactions of catalytic oxidation of furan and hydrofuran compounds. I. General principles of the oxidation of furan in the system hydrogen peroxide-vanadium(IV) compounds depending on the type of solvent and catalyst
Poskonin,Povarova,Badovskaya
, p. 543 - 547 (2007/10/03)
The oxidation of furan by aqueous hydrogen peroxide catalyzed by vanadium(IV) compounds was studied in homogeneous aqueous alcohol medium and a heterogeneous system in the presence of tridecylmethylammonium chloride. The optimum conditions of the process were determined for both versions. It was shown that they are similar in direction, duration, and degree of conversion of furan. At the same time, the composition and total yield of the products, as well as their yields in the organic and aqueous phases, depend on the type of solvent and vanadium catalyst. 1996 Plenum Publishing Corporation.
Sensitized Photooxygenation of 6-Heteroatom-Substituted Fulvenes: Primary Products and Their Chemical Transformations
Zhang, Xiaojun,Lin, Feng,Foote, Christopher S.
, p. 1333 - 1338 (2007/10/02)
Sensitized photooxygenation of 6,6-diethoxyfulvene (1) and 6,6-(ethylenedithio)fulvene (9) at -78 deg C afforded diethoxyfulvene endoperoxide 2 and (ethylenedithio)fulvene endoperoxide 10, respectively, as primary products.Further irradiation resulted in formation of the novel bisperoxides 3 and 11 from cycloaddition of 1O2 to the exocyclic double bond of the corresponding endoperoxides.The initial endoperoxides were characterized by NMR at low temperature and underwent a variety of chemical transformations to give highly oxygenated cyclopentane derivatives.In contrast, photooxygenation of 6,6-dipiperidinofulvene (16) and 6-(dimethylamino)fulvene (17) did not lead to chemical reaction; these compounds physically quench 1O2 with rate constants on the order of 1E8 M-1 s-1.
Anodic Oxidation of Unsaturated Aliphatic Ethers in Aqueous Electrolytes
Cyr, A.,Wermeckes, B.,Beck, F.
, p. 602 - 607 (2007/10/02)
2,5-Dihydrofuran 1 was galvanostatically oxidized in aqueous electrolytes on Pt and PbO2 anodes at current densities of 10 to 50 mA cm-2.Under acidic conditions maleic dialdehyde 2 was obtained on both electrodes with a current efficiency (c.e.) of up to 50percent.In the alkaline region (pH 10) 4-hydroxy crotonic aldehyde 3 (Pt) or 2,5-dihydrofuranone 4 (PbO2) become the main products with c.e.'s of 29percent and 27percent, respectively, depending on the anode material.The influence of pH and of the anode material are discussed in detail. 2,3-Dihydrofuran 7, vinyl ethyl ether 8 and for comparison, furan 9 were studied in addition.
Ring Fragmentation Reactions on the Photooxidations of Toluene and o-Xylene
Shepson, P. B.,Edney, E. O.,Corse, E. W.
, p. 4122 - 4126 (2007/10/02)
Irradiations of toluene and o-xylene in the CH3ONO/NO/air system (used to generate OH radicals) have been found to produce significant yields of various C4 and C5 dicarbonyl compounds, aldehydes, and substituted furans.The mechanistic implications, that i
POPELLANES-LII THE REACTION OF CONJUGATED DIENIC PROPELLANES WITH SINGLET OXYGEN
Landheer, Iman,Ginsburg, David
, p. 133 - 142 (2007/10/02)
The reactions of propellanes containing one or two cyclohexadiene rings with singlet oxygen take the course of exclusive syn-attack with respect to a hetero-ring containing two CO groups.When only one or no CO group is found in the hetero ring, both syn- and anti-attack occur.The former course is interpreted in terms of secondary orbital interactions wich stabilize the transition state for syn-attack.
