Radiation-Induced Oxidation

Radiation-induced oxidation of alcohols is a non-chain reaction when the temperature is sufficiently low and kp/ /2kt /H /[RH]. In this case, the reaction rate is proportional to the irradiation intensity (/) and is virtually independent of temperature [46,63—69]. 

Above a certain temperature, the oxidation becomes a chain reaction. The increase in radiolytic yield, G, with temperature and a dependence of G on / of the type [46] 

The composition of alcohol radiolysis products is very different in the presence and absence of 02, due to the reactions [65] 

The values of G for methanol and other primary alcohols are listed in Tables 2 and 3. Radiation-induced oxidation of rc-butanol was studied by Komarov et al. [66,67] over a wide temperature range. 

Hughes and Makada [47] have studied the radiation-induced oxidation of 2-propanol in acid and alkaline aqueous solutions at 20° C. Alcohol oxidation in acid solution at [RH] 0.1 mole l 1 proceeds by a chain mechanism 

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Garrison, W.M., Jayko, M.E. and Bennett, W. (1962). Radiation induced oxidation of protein in aqueous solution Radiat. Res. 16, 483—493. 

VV Saraeva. Radiation Induced Oxidation of Organic Compounds. Doctoral Thesis Dissertation, Institute of Electrochemistry, Moscow, 1970, pp 1-36 [in Russian]. 

The mechanism and kinetics of ether oxidation are discussed in monographs [7-10], The valuable information about the chemistry of ether oxidation is given in Ref. [8]. The photo-and radiation-induced oxidation of ethers are described. 

This effect is not due to deformation impact on hydroperoxide stability rate constants of thermal decomposition of hydroperoxide in PP are the same for both isotropic and deformed samples. Moreover, even at 20°C, when hydroperoxide is stable, its escape during radiation-induced oxidation sharply drops with the growth of X. 

The sensitivity to ionizing radiation is maximal in those cells able to activate a co-ordinate program of cell death (apoptosis) primed by the radiation-induced oxidative stress. Albeit apoptosis is a nuclear event and radiation-induced DNA damage is probably the most relevant mechanism of initiation of apoptosis, the control of the execution phase (and sometime also the initiation) takes place at the mitochondrial level. Radioresistance occurs... 

Vile, G. R, and Tyrrell, R. M. 1995. UVA radiation-induced oxidative damage to lipids and proteins in vitro and in human skin fibroblasts is dependent on iron and singlet oxygen. Free Rad. Biol. Med. 18 721-22. 

The gamma-radiation-induced oxidation of 2-propanol has been investigated. Acetone and hydrogen peroxide are the principal products and arise via a chain reaction in aqueous acid solutions at high concentrations of 2-propanol. In neutral solutions of 2-propanol and in solutions of methanol and ethanol, no such chain reactions are observed. The reasons for this are discussed along with the implications of the results for the hydroxyl radical yield in water radiolysis. 

Although the radiation-induced oxidation of ethanol has been fully in-- vestigated (2, 22, 23), little work has been published on the oxidation of other alcohols. In connection with a project concerned with the relative rates of hydroxyl radical reactions using 2-propanol as reference solute, it was thought desirable first to investigate the radiation chemistry of 2-propanol-oxygen solutions both in aqueous solution and pure 2-propa-nol. The results of this investigation are presented here. 

At the lowest concentrations of 2-propanol, 10"2 M, there is reasonable agreement between calculated and experimental results. These results then are consistent with the assumption that acetone is the only oxidation product from the radical produced from 2-propanol in aqueous solution containing oxygen. It has similarly been shown (23) that acetaldehyde is the only organic oxidation product in the radiation-induced oxidation of aqueous ethanol. However, our experiments indicate that in... 

The radiation-induced oxidation of cyanide and sulfide have been suggested by Selke (Sll) as an attractive method of waste disposal. By using radiation for destruction rather than for synthesis, side-product and purification problems are eliminated. 

Hoff, J. E., Wertheim, J. H. and Proctor, B. E. 1959. Radiation preservation of milk and milk products. V. Precursors to the radiation-induced oxidation flavor of milk fat. J. Dairy Sci. 42, 468-475. 

A second important series of experiments dealt with membrane chemistry composed of 5-cho1esten-3B-o1 (cholesterol) and partially oxidized phospholipid. The ultraviolet radiation Induced oxidation led to formation of hydroperoxide moieties at the unsaturated sites on some of the phospholipid acyl chains listed In Table II. The Cjg 2 chain was chosen as a reactive representative... 

Burchill CE, Wollner GP (1972) Radiation-induced oxidation of 2-propanol by nitrous oxide in alkaline aqueous solution. Can J Chem 50 1751-1756... 

Holian J, Garrison WM (1966) Radiation-induced oxidation of cytosine and uracil in aqueous solution of copper(ll). Nature 212 394-395... 

Thornalley PJ, Vasak M (1985) Possible role for metallothionein in protection against radiation-induced oxidative stress. Kinetics and mechanism of its reaction with superoxide and hydroxyl radicals. Biochim Biophys Acta 827 36-44... 

Soebianto, Y.S., Katsumura, Y., Ishigure, K., Kubo, J., Hamakawa, H., Kudoh, H., Seguchi, T. 1996. Radiation induced oxidation of liquid alkanes as a polymer model. Radiat. Phys. Chem. 48(4) 449-456. 

Curcuminoids can also act as photoche-moprotective agents that provide protection against UVB radiation-induced oxidative... 

There was an increased yield ofconjugated olefin, ( <.onj. (Table 19 and Fig. 20) in the y-radiolysis of aqueous sodium linoleate when the concentration of the solute exceeded the CMC (Gebicki and Allen, 1969). A reaction mechanism for this radiation-induced oxidation is given in equations 49-54. At high oxygen concentration reaction (50) is much... 

Ekeroth E, Roth O, Jonsson M. (2006) The relative impact of radiolysis products in radiation induced oxidative dissolution of UO2. J Nud Mater 355 38-46. 

Radiation-Induced Oxidation of Substituted Benzenes Structure-Reactivity Relationship... 

Structure-reactivity relationship. This chapter is not a comprehensive review of the published work on radiation-induced chemical oxidation of benzene derivatives, nor does it cover redox properties and energetics of radical cations of substituted benzenes. The latter aspects have already been reviewed by Jonsson " earlier. In a series of papers,Jonsson and co-workers have clearly shown correlations between substituent pattern and redox properties of radical cations of substituted benzenes. Further, it has been shown by them that the product pattern is governed by the charge distribution on the radical cation and the electron density distribution on the corresponding substituted benzene. This chapter is an overview of the work carried out on radiation-induced oxidation of substituted benzenes with emphasis on the contribution to the area from our research group. 

The experimental methodology in radiation-induced oxidation of benzene systems involved the measurement of rate constants and the transient absorption spectra by pulse radiolysis and the determination of yields of hydroxylated products on oxidation of the hydroxycyclo-hexadienyl radicals under steady-state conditions. The two commonly used oxidants — K3Fe(CN) "and IrCl " — convert quantitatively the OH adducts to the corresponding phenolic products. Thus, the pulse radiolysis technique in combination with product analysis using analytical techniques such as UV-VIS spectroscopy, HPLC, GC-MS, etc. under steady state conditions has provided valuable information in the understanding of the oxidation reaction mechanism of aromatics in... 

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