Polycyclic aromatics oxidation

Several industrial facilities near a residential area emit tlie inhalable pollutants ethylene oxide, polychlorobiphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Tlie aimual average concentration of ethylene oxide, PCBs, and PAHs are 10 pg/in, 2 pg/m, and 5 pg/m, respectively. 

Reduction of fullerenes to fullerides — Reversible electrochemical reduction of Ceo in anhydrous dimethylformamide/toluene mixtures at low temperatures leads to the air-sensitive coloured anions Qo" , ( = 1-6). The successive mid-point reduction potentials, 1/2, at -60°C are -0.82, -1.26, -1.82, -2.33, —2.89 and —3.34 V, respectively. Liquid NH3 solutions can also be used. " Ceo is thus a very strong oxidizing agent, its first reduction potential being at least 1 V more positive than those of polycyclic aromatic hydrocarbons. C70 can also be reversibly reduced and various ions up to... 

The branched oligo(arylene)s 37 and 40 can undeigo a further oxidative cyclization with copper(ll) chloride or triflate/aluminum trichloride leading to the formation of large, hitherto unknown polycyclic aromatic hydrocarbons PAHs 41 and 42. 

Dihydro-9,10-epoxyphenanthrene and related arene oxides are of considerable interest as carcinogens formed by polycyclic aromatic hydrocarbons in vivo.45 Phenanthrene oxide does not isomerize to the corresponding dibenzoxepin under thermal conditions. Photolysis of... 

Epoxides are often encountered in nature, both as intermediates in key biosynthetic pathways and as secondary metabolites. The selective epoxidation of squa-lene, resulting in 2,3-squalene oxide, for example, is the prelude to the remarkable olefin oligomerization cascade that creates the steroid nucleus [7]. Tetrahydrodiols, the ultimate products of metabolism of polycyclic aromatic hydrocarbons, bind to the nucleic acids of mammalian cells and are implicated in carcinogenesis [8], In organic synthesis, epoxides are invaluable building blocks for introduction of diverse functionality into the hydrocarbon backbone in a 1,2-fashion. It is therefore not surprising that chemistry of epoxides has received much attention [9]. 

Major unknowns in the mechanism by which a hydrocarbon fuel bums concern the pyrosynthesis reactions that lead to the formation of polycyclic aromatic hydrocarbons (PAHs) and soot and the oxidation chemistry of atoms other than carbon and hydrogen (heteroatoms) in the fuel, particularly nitrogen, sulfur, and halogens. 

Polycyclic aromatic hydrocarbons, indole and quinoline derivatives, naphthylamines, azulenes Silica gel G Formation of oxidation products via the initially formed iodine complexes [15]... 

Polycyclic aromatic hydrocarbons Silica gel G Monovalent oxidation of the iodine complexes via radical cations yields dimeric or tetrameric aromatics [16]... 

Hammel KE, B Kalyanaraman, TK Kirk (1986) Oxidation of polycyclic aromatic hydrocarbons and dibenzo(p)dioxins by Phanerochaete chrysosporium ligninase. J Biol Chem 261 16948-16952. 

Bogan BW, RT Lamar (1995) One-electron oxidation in the degradation of creosote polycyclic aromatic hydrocarbons by Phanerochaete chrysosporium. Appl Environ Microbiol 61 2631-2635. 

Coates JD, RT Anderson, DR Lovley (1996) Oxidation of polycyclic aromatic hydrocarbons under sulfate-reducing conditions. Appl Environ Microbiol 62 1099-1101. 

Mahaffey WR, DT Gibson, CE Cerniglia (1988) Bacterial oxidation of chemical carcinogens formation of polycyclic aromatic acids from benz[a]anthracene. Appl Environ Microbiol 54 2415-2423. 

The oxidation of pollutants by laccase is normally limited to aromatic compounds with one phenolic group, but in the presence of low molecular weight compounds, known as mediators, it can also oxidize other compounds, such as dyes [58] or alkenes and polycyclic aromatic hydrocarbons [59]. 

Tinoco, R., and VazquezDuhalt, R., Chemical Modification of Cytochrome C Improves Their Catalytic Properties in Oxidation of Polycyclic Aromatic Hydrocarbons. Enzyme and Microbial Technology, 1998. 22(1) pp. 8-12. 

Ortiz Leon, M. Velasco, L., and Vazquez-Duhalt, R., Biocatalytic Oxidation of Polycyclic Aromatic-Hydrocarbons by Hemoglobin and Hydrogen-Peroxide. Biochemical and Biophysical Research Communications, 1995. 215(3) pp. 968-973. 

Torres, E. Tinoco, R., and Vazquez-Duhalt, R., Biocatalytic oxidation of polycyclic aromatic hydrocarbons in media containing organic solvents. Water Science and Technology, 1997. 36(10) pp. 37 4. 

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