Topic
Benzene
About: Benzene is a research topic. Over the lifetime, 19747 publications have been published within this topic receiving 340878 citations. The topic is also known as: C6H6 & [6]annulene.
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TL;DR: In this paper, the authors used 13C and 1H NMR spectra of graphite oxide derivatives to confirm the assignment of the 70 ppm line to C−OH groups and allow them to propose a new structural model for graphite oxides.
Abstract: Graphite oxide (GO) and its derivatives have been studied using 13C and 1H NMR. NMR spectra of GO derivatives confirm the assignment of the 70 ppm line to C−OH groups and allow us to propose a new structural model for GO. Thus we assign the 60 ppm line to epoxide groups (1,2-ethers) and not to 1,3-ethers, as suggested earlier, and the 130 ppm line to aromatic entities and conjugated double bonds. GO contains two kinds of regions: aromatic regions with unoxidized benzene rings and regions with aliphatic six-membered rings. The relative size of the two regions depends on the degree of oxidation. The carbon grid is nearly flat; only the carbons attached to OH groups have a slightly distorted tetrahedral configuration, resulting in some wrinkling of the layers. The formation of phenol (or aromatic diol) groups during deoxygenation indicates that the epoxide and the C−OH groups are very close to one another. The distribution of functional groups in every oxidized aromatic ring need not be identical, and both ...
3,076 citations
TL;DR: In this paper, it was shown that the partial pressures of the reacting substances appeared to influence the reaction rate, and a formula depicting this influence was derived, which may be interpreted by assuming two successive reactions, namely the reaction between the aromatic and the oxygen on the surface, and the re-oxidation of the partly reduced surface by means of oxygen.
Abstract: Summary All technically interesting reactions carried out with vanadium oxide catalysts are marked by their highly exothermic character, which forms an impediment to the investigation of the kinetics of these processes. In the present study use was made of a fluid bed, in which the temperature is uniform. The oxidation of the following substances: benzene, toluene, naphthalene, and anthracene has been studied. The partial pressures of the reacting substances were varied to the greatest possible extent. Both reaction components appeared to influence the reaction rate. A formula depicting this influence is derived. This formula may be interpreted by assuming two successive reactions, namely the reaction between the aromatic and the oxygen on the surface, and the re-oxidation of the partly reduced surface by means of oxygen. The formula may be reduced to an equation by which also the data on the oxidation of sulphur dioxide by means of vanadium oxide catalysts found in the literature are well described. Using kinetic data it is possible to determine the optimum temperature distribution in a fixed bed reactor used for the oxidation of sulphur dioxide and to make calculations of the ratio between the amounts of catalyst to be used in the various stages of a multiple-stage reactor. The results of these calculations have been compared with practical experience.
1,613 citations
TL;DR: The use of metal phthalocyanines as catalysts for the oxidation of organic compounds has been described in the literature as mentioned in this paper, and a number of these reports were tested as cathode catalysts in fuel cells.
Abstract: THE use of metal phthalocyanines as catalysts for the oxidation of organic compounds has been described in the literature. A number of papers by C. Paquot have reported the catalytic activity of the nickel phthalo-cyanine in the oxidation of long-chain fatty acids and their esters1, saturated ketones2, benzene hydrocarbons such as toluene and ethylbenzene3, cyclohexane hydrocarbons4, and pinene5. In addition, M. Baldwin reported the oxidation of olefins, principally isobutylene, by copper phthalocyanine supported on pumice6. A. Cook7 described the activity of iron phthalocyanine for the catalytic decomposition of hydrogen peroxide. A slow degradation of the catalyst was observed which was ascribed to a complex formed between the peroxide and the phthalocyanine. On the basis of these reports, a number of phthalocyanines were tested as cathode catalysts in fuel cells.
1,607 citations
1,010 citations
TL;DR: The catalytic properties of the metal-organic framework compound Cu 3 (BTC) 2 (H 2 O) 3 ǫ x H 2 O (BTC=benzene 1,3,5-tricarboxylate) were explored in this article.
Abstract: The catalytic properties of the metal-organic framework compound Cu 3 (BTC) 2 (H 2 O) 3 · x H 2 O (BTC=benzene 1,3,5-tricarboxylate) were explored. Cu 2 O-free powder samples of Cu 3 (BTC) 2 (H 2 O) 3 · x H 2 O were obtained using an improved synthesis at 393 K under hydrothermal conditions. The microporous material has a high specific pore volume of 0.41 cm 3 g −1 and a pore diameter of 10.7 A (Horvath-Kawazoe). Removal of the three copper-bound water molecules allows to access the Lewis acid copper sites. The exchange of coordinated water by substrates or solvent molecules is recognized from the color change of the compound. For chemisorbed benzaldehyde, the IR stretching frequency ν (CO) is decreased from 1702 to 1687 cm −1 . The chemisorption results in an activation of benzaldehyde for the liquid phase cyanosilylation with a reasonable yield of 50–60% after 72 h (313 K) and a high selectivity. Filtration experiments demonstrate that the reaction mechanism is heterogeneous. Coordinating solvents such as THF completely block the Lewis acid sites of the catalyst. Solvents such as CH 2 Cl 2 or higher reaction temperatures (353 K) cause decomposition of the catalyst.
981 citations