Reactivity, mononuclear oxygen species,

R. Mason, Catalysis in chemistry and biochemistry, Catal. Lett., 2004, 98, 1. M. Che, A. J. Tench, Characterisation and reactivity of mononuclear oxygen species on oxide surfaces, Adv. Catal., 1982, 31, 78. 

Characterization and Reactivity of Mononuclear Oxygen Species on Oxide Surfaces M. Che and A. J. Tench Sulfur Poisoning of Metals C. H. Bartholomew, P. K. Agrawal, and... 

Characterization and Reactivity of Mononuclear Oxygen Species on Oxide Surfaces... 

Despite several decades of studies devoted to the characterization of Fe-ZSM-5 zeolite materials, the nature of the active sites in N20 direct decomposition (Fe species nuclearity, coordination, etc.) is still a matter of debate [1], The difficulty in understanding the Fe-ZSM-5 reactivity justifies a quantum chemical approach. Apart from mononuclear models which have been extensively investigated [2-5], there are very few results on binuclear iron sites in Fe-ZSM-5 [6-8], These DFT studies are essentially devoted to the investigation of oxygen-bridged binuclear iron structures [Fe-0-Fe]2+, while [FeII(p-0)(p-0H)FeII]+ di-iron core species have been proposed to be the active species from spectroscopic results [9]. We thus performed DFT based calculations to study the reactivity of these species exchanged in ZSM-5 zeolite and considered the whole nitrous oxide catalytic decomposition cycle [10],... 

The synthesis, structure, and superoxide dismutase mimetic activity in vitro and the protection against reactive oxygen species in vivo of mononuclear copper complexes with 2-(4-methylphenylsulfamoyl)-6-nitrobenzothiazole have been reported [602], Like 1,2,3-benzoxadiazoles, nitroderivatives of 1,2,3-benzothiadiazoles were obtained on diazotization of the corresponding or/Zzo-aminothiophcnolcs [213, 218, 583], The initial or/Zzo-thiophcnols for this reaction were synthesized by nucleophilic substitution of halogen in ort/zo-halogenoanilines. It turned out that 4-nitro- and... 

Superoxide Reductase (see Iron Proteins with Mononuclear Active Sites). Detoxification of reactive oxygen species in anaerobic microorganisms has recently been shown to center around SOR, a novel mononuclear iron enzyme that reduces superoxide to hydrogen peroxide (see equation 4), rather than dismuting superoxide to oxygen and hydrogen peroxide as is the case for the superoxide dismutases found in aerobic organisms. 

D. Roos, B.G.J.M. Bolscher and M. de Boer, Generation of reactive oxygen species by phagocytes, in Mononuclear Phagocytes. Biology of Monocytes and Macrophages, R. van Furth (ed.), Kluwer Academic Publishers, Dordrecht, 1992, p. 243. 

Perez-Maldonado et al. (2005) studied DDT-induced oxidative damage in human blood mononuclear cells. They reported that DDT and its metabolites, p, p -DDD and p, p -ddE induced apoptosis in human peripheral blood mononuclear cells which was preceded by increase in reactive oxygen species. A-Acetyl-L-cysteine inhibited such induction of apoptosis. 

The identification of the reaction intermediates formed between [CrCl(l)] and iodosylbenzene (PhIO) were also investigated by EPR [115, 116]. The first intermediate was characterised by the reported spin-Hamiltonian parameters of g = 1.970-1.974, Acc = 54 MHz, 4 = 4.5-5.6 MHz, whilst the second species produced the parameters of g = 1.976-1.980, Acr = 54 MHz, 21 = 5.6-6.4 MHz. Based on the CW-EPR and H-NMR investigation, the first intermediate was identified as a reactive mononuclear oxochromium(V) intermediate, labelled [CrVO(l)L] where L = CP or solvent molecule. The second intermediate was identified as an inactive mixed-valence binuclear [L(2)Cr OCr (2)L] complex. Bryliakov et al. [115, 116] thereby proposed that the [CrCl(l)]-catalysed epoxida-tion of alkenes proceeds in accordance with a modified oxygen rebound cycle . 

Apparently, cyanidin 3-O-rutinoside (5) treatment could not lead to the accumulation of the increased reactive oxygen species (ROS) in normal human peripheral blood mononuclear cells without the cytotoxic effects. 

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