scholarly journals Study on decomposition of organic halogen compounds in aqueous solution. II. Photoinduced decomposition of trihalomethanes in aqueous solution. Effects of H2O2 on the decomposition rate and characteristics of the reaction with OH radical.

1985 ◽  
pp. 970-975 ◽  
Author(s):  
Takashi OGITA ◽  
Hiroshi HATTA ◽  
Sei-ichi NISHIMOTO ◽  
Tsutomu KAGIYA
Keyword(s):  
Aqueous Solution ◽  
Decomposition Rate ◽  
Oh Radical ◽  
Organic Halogen ◽  
Halogen Compounds

THE RADIOLYSIS OF SOME ORGANIC HALOGEN COMPOUNDS IN AQUEOUS SOLUTION

1960 ◽  
Vol 38 (1) ◽  
pp. 77-93 ◽  
Author(s):  
R. J. Woods ◽  
J. W. T. Spinks
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Organic Compounds ◽  
Gamma Rays ◽  
Organic Halogen ◽  
Halogen Compounds ◽  
Dilute Aqueous Solutions ◽  
Saturated Solutions

Dilute aqueous solutions of some halogen-substituted ethanols, acetaldehydes, and acetates have been irradiated with Co60 gamma rays, and the yield of acid products determined. Irradiations were carried out using air-saturated solutions and also solutions from which the air had been displaced by nitrogen or hydrogen. The acid yields are correlated with the structure of the organic compounds.

2-Deoxyribose Radicals in the Gas Phase and Aqueous Solution. Transient Intermediates of Hydrogen Atom Abstraction from 2-Deoxyribofuranose

2005 ◽  
Vol 70 (11) ◽  
pp. 1769-1786 ◽  
Author(s):  
Luc A. Vannier ◽  
Chunxiang Yao ◽  
František Tureček
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Atom ◽  
Gas Phase ◽  
Computational Study ◽  
Hydrogen Atom Abstraction ◽  
Oh Radical ◽  
Free Energies ◽  
Intramolecular Hydrogen ◽  
Solvation Free Energies ◽  
Transient Intermediates

A computational study at correlated levels of theory is reported to address the structures and energetics of transient radicals produced by hydrogen atom abstraction from C-1, C-2, C-3, C-4, C-5, O-1, O-3, and O-5 positions in 2-deoxyribofuranose in the gas phase and in aqueous solution. In general, the carbon-centered radicals are found to be thermodynamically and kinetically more stable than the oxygen-centered ones. The most stable gas-phase radical, 2-deoxyribofuranos-5-yl (5), is produced by H-atom abstraction from C-5 and stabilized by an intramolecular hydrogen bond between the O-5 hydroxy group and O-1. The order of radical stabilities is altered in aqueous solution due to different solvation free energies. These prefer conformers that lack intramolecular hydrogen bonds and expose O-H bonds to the solvent. Carbon-centered deoxyribose radicals can undergo competitive dissociations by loss of H atoms, OH radical, or by ring cleavages that all require threshold dissociation or transition state energies >100 kJ mol-1. This points to largely non-specific dissociations of 2-deoxyribose radicals when produced by exothermic hydrogen atom abstraction from the saccharide molecule. Oxygen-centered 2-deoxyribose radicals show only marginal thermodynamic and kinetic stability and are expected to readily fragment upon formation.

Studies in polymerization. XIII. The activated initiation of vinyl polymerization by metal carbonyls

1962 ◽  
Vol 268 (1335) ◽  
pp. 553-566 ◽  
Keyword(s):  
Kinetic Mechanism ◽  
Molybdenum Hexacarbonyl ◽  
Metal Carbonyls ◽  
Group Vi ◽  
Radical Intermediates ◽  
Vinyl Polymerization ◽  
Organic Halogen ◽  
Halogen Compounds ◽  
Iodine Compounds ◽  
Reaction Proceeds

It has been found that the hexaearbonyls of group VI metals in the presence of some organic halogen compounds are active initiators of vinyl polymerization. Molybdenum hexacarbonyl is the most active, and halogen compounds containing —CC1 3 , —CBr 3 are generally more effective than those with fewer halogen atoms joined to a single carbon. Fluorine and iodine compounds are inactive. A study has been made of the initiation of the polymerization of methyl methacrylate by the Cr(CO) 6 + CCl 4 system. The polymerization is markedly retarded by carbon monoxide. It is shown that the reaction proceeds through free-radical intermediates, and a kinetic mechanism for initiation is derived (equation (4)) leading to the expression (5) for the rate of chain starting. This quantity may be calculated from (5) with the aid of the numerical values in table 3. Kinetic observations are in satisfactory agreement with this mechanism. The nature of the participating reactions is discussed.

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