Radiation Chemistry Of Aqueous Solutions Research Articles

Radiation chemistry of aqueous solutions of simple RCN [hydrogen or alkyl cyanide] compounds

Radiation chemistry of aqueous solutions of simple RCN [hydrogen or alkyl cyanide] compounds

On the radiation chemistry of aqueous solutions of cupric ethylenediamine tetra-acetate

Neutral and alkaline aqueous solutions of cupric ethylenediamine tetra-acetate (C) were irradiated with X-rays both in the presence and in the absence of dissolved oxygen. Radiolytic yields of decomposition of C were determined. The formation of hydrogen peroxide and formaldehyde in the system was also followed. It has been observed that the radiolysis is initiated by attack both at the ligand and at the central metal ion of the metal chelate by the free radicals derived from water. A radiolytic mechanism is proposed and discussed in the light of the observed results. From competition kinetic studies with CH 3OH in neutral solution the rate constant k(OH+C) was found to be 2·04 × 10 9 dm 3 mol −1s −1.

Concentration effects on primary processes in the radiation chemistry of aqueous solutions

Concentration effects on primary processes in the radiation chemistry of aqueous solutions

Inorganic redox systems in graft polymerization onto cellulosic materials

AbstractA review is attempted of the inorganic redox systems in the context of free radical graft polymerization. Metal ion‐H2O2 redox systems are considered as part of the spectrum of such inorganic and organic reagents used for the purpose. It is emphasized that the chemistry of these latter systems in particular is much like the radiation chemistry of aqueous solutions caused by high energy ionizing radiations. On the other hand, these systems involve low energy and therefore are less damaging to the substrate and relatively more specific. The reactivity of free radicals in these systems varies subtly with the system and the medium. It is observed that only ceric ion method and [Fe(II); Fe(III)] ‐H2O2 system are most successful in grafting onto cellulosic materials. Attention is paid to the features which makes these systems so useful. Concrete results from ESR study are presented which underline the nonspecific nature of various free radical producing systems including radiations.

Competition for eaq- between several scavengers at high concentrations and its implications on the relevance of dry electrons in the radiation chemistry of aqueous solutions

Competition for eaq- between several scavengers at high concentrations and its implications on the relevance of dry electrons in the radiation chemistry of aqueous solutions

Radiation Chemistry of Oxygenated Aqueous Solutions

The activity in radiation chemistry in recent years has been so extensive that it seems impossible to review the whole field. This review will cover only problems in the radiation chemistry of aqueous solutions. Even within this limited field numerous papers have been published as well as several books, symposia, and reviews (1-1 5). Before the techniques of pulse radiolysis were developed about a decade ago, most studies dealt with measurements of yields and relative rate constants. The identity of radicals formed in water was inferred from such studies. The diffusion model was generally accepted to explain the effect of radiations of various LET, the effect of solutes on G values, and various other related phenomena. The subject as it was known in 1 960 was ably summarized by Allen in his book (16). In the last decade more direct kinetic studies of radical-radical reactions and of reactions of radicals with solutes have been carried out. These studies have helped to elucidate reaction mechanisms and specifically identify intermediates and have provided a large compilation of rate constants of reactions of various solutes with eaq, OH, and H atoms (17). For many of these intermediates, physical properties such as absorption spectra, ESR spectra, conductivities pKs, etc were de­ termined. First I would like to make a few general remarks on the diffusion model and then devote the remaining sections of the review to a summary of the problems and properties of the intermediates found in air-free and air­ saturated aqueous solutions as they are currently known.

The radiation chemistry of aqueous solutions of ferric ethylenediamine tetraacetate

Aqueous solutions of ferric ethylenediamine tetraacetate (F) at pH 1 were irradiated with X-rays both in the presence and in the absence of dissolved oxygen. Radiolytic yields of decomposition of F were determined. Formaldehyde and ferrous ion were also detected amongst the radiolysis products. It has been concluded that the radiolysis is initiated by attack both at the ligand and at the central metal ion of the metal chelate by the free radicals derived from water. A reaction mechanism for the radiolytic degradation of F in aqueous solution has been described. Effects of ferrous ion and methanol on the course of radiolysis were also investigated. From such competition kinetic studies the ratios of the rate constants k OH+Fe 2+ k OH+F and k OH+F k OH+CH 3 OH were found to be 0·48 and 1·7 respectively.

Radiation chemistry of aqueous solutions of trichlorofluoromethane, dichlorodifluoromethane, and chlorotrifluoromethane

Radiation chemistry of aqueous solutions of trichlorofluoromethane, dichlorodifluoromethane, and chlorotrifluoromethane

Contribution of hydrogen atoms to GH2 in the radiation chemistry of aqueous solutions

Contribution of hydrogen atoms to GH2 in the radiation chemistry of aqueous solutions

Radiation chemistry of aqueous solutions of indole and its derivatives

2,2-Bis-(3-indoly)indol-3(2H)-one and polymer are the major products derived by γ-irradiation of aqueous solutions of indole in argon, nitrous oxide, and oxygen. Small amounts of indoxyl, indoxyl red, indigo, and indirubin are also formed. Anthranilic acid appears to be produced in oxygen. A reaction pathway is discussed which accounts for the high G(–indole) values and the strong oxygen-dependence of these reactions. By use of pulse radiolysis, the absorption spectra were recorded for the transient hydroxyl radical adducts for indole, 2-, 3-, and 5-methylindole, 1,2- and 2,3-dimethylindole, and indoline. Rate constants for the reactions of hydroxyl radicals with a number of indoles were also measured.

Molecular hydrogen formation (GH2) in the radiation chemistry of aqueous solutions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular hydrogen formation (GH2) in the radiation chemistry of aqueous solutionsE. Peled and Gideon CzapskiCite this: J. Phys. Chem. 1970, 74, 15, 2903–2911Publication Date (Print):July 1, 1970Publication History Published online1 May 2002Published inissue 1 July 1970https://doi.org/10.1021/j100709a010RIGHTS & PERMISSIONSArticle Views117Altmetric-Citations40LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (928 KB) Get e-Alerts

Chapter 8. The radiation chemistry of aqueous solutions

Chapter 8. The radiation chemistry of aqueous solutions

Applications of the spur diffusion model to the radiation chemistry of aqueous solutions

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApplications of the spur diffusion model to the radiation chemistry of aqueous solutionsHarold A. SchwarzCite this: J. Phys. Chem. 1969, 73, 6, 1928–1937Publication Date (Print):June 1, 1969Publication History Published online1 May 2002Published inissue 1 June 1969https://doi.org/10.1021/j100726a047RIGHTS & PERMISSIONSArticle Views444Altmetric-Citations196LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

The radiation chemistry of aqueous solutions of sodium nitroprusside

The radiation chemistry of aqueous solutions of nitroprusside has been studied by pulse and steady-state methods. The data show that nitroprusside is reduced by e aq −, H and CO 2 −, and oxidized by OH, and therefore, contrary to a previous proposal, it is not a specific reagent for excited water molecules. The relevant rate constants are: k(e aq − + Fe(CN) 5NO 2-) = 2·2 × 10 10 1 mol −1s −1, k(CO 2 − + Fe(CN) 5NO 2- = 3·7 × 10 8 1 mol −1 s −1, k(OH + Fe(CN) 5NO 2−) = 1·2 × 10 7 l mol −1 s −1. The photodecomposition of nitroprusside at λ > 300 nm proceeds by two mechanisms: 1. (i) Fe(CN) 5NO 2− + hv → Fe(CN) 5 2− + NO, 2. (ii) Fe(CN) 5NO 2− + hv → Fe(CN) 5NO − + e aq −.

Studies on the chemical basis of cellular radiosensitization by 5-bromouracil substitution in DNA. I. Pulse- and steady-state radiolysis of 5-bromouracil and thymine.

SummaryPulse- and steady-state radiolysis studies show two major differences in the radiation chemistry of aqueous solutions of E. coli DNA (DNA) and bromouracil substituted DNA (BU-DNA): on exposure of N2-saturated solutions to low doses of radiation the absorbance of BU-DNA increases while that of DNA decreases; the free radicals formed by OH· attack on BU-DNA decay more rapidly than those on DNA. The differences are explained with the help of results from the accompanying paper by a mechanism involving conversion of the BU moiety of BU-DNA to a uracil (U) moiety by reaction of BU-DNA with organic free radicals. Uracil-5-yl radicals are formed which may abstract H· from neighbouring deoxyribose moieties to give uracil and a radical which may lead to a single-strand break. A hypothesis for BU radiosensitization, based on these and earlier results, account for (a) more DNA base damage and (b) more single-strand breaks in BU-DNA than in DNA; and (c) formation of U in BU-DNA.

On a pH Dependent Increase in the Yield of Available Radicals in the Radiation Chemistry of Aqueous Solutions*

On a <i>pH</i> Dependent Increase in the Yield of Available Radicals in the Radiation Chemistry of Aqueous Solutions*

Radiation chemistry of aqueous solutions of ethanol

Radiation chemistry of aqueous solutions of ethanol

Radiation chemistry of aqueous solutions containing carbon monoxide and oxygen between pH 0.4 and 12

G(H2), G(CO2), G(H2O2), G(—O2) and G(—CO) have been measured for X-irradiated aqueous solutions containing CO and O2 in the pH range 0.4–12. A reaction mechanism is used as a basis for calculation of primary yields. Whereas GH2= 0.48±0.05 and GH2O2= 0.74±0.09 are substantially independent of pH, G–H2O, GOH and (Ge–aq+GH) each diminish by about 0.9 unit as the pH is increased from 1.4 to 2.2, thereafter remaining constant at 3.7±0.2, 2.14±0.04 and 2.8±0.15 respectively.

Kinetics of the decomposition of hydrogen peroxide in presence of ferricyanide

THE decomposition of hydrogen peroxide has been studied ~1'2) in the presence of a large number of metal ions and their complexes. Interest in radiation chemistry of aqueous solutions where hydrogen peroxide is one of the products and the use of acidic ferrous sulphate solutions as dosimeter in these studies have particularly stimulated ~1'2~ the investigation of the kinetics of decomposition of hydrogen peroxide in presence of Fe 2+, Fe 3+ and their complexes. Ferrous sulphate solution can be used as a dosimeter under acidic conditions only, as at higher pH the hydrolysis of Fe 2+ and Fe ~interferes. Recent ~a-~ studies have shown the possibility of using the aqueous solutions of ferro and ferricyanides over a range o f p H as dosimeter. In most of these studies the reaction between hydrogen peroxide and ferro and ferricyanides have been neglected. The present work aims at studying the interaction of ferricyanide with hydrogen peroxide over a range of pH, concentration and temperature. Early work in this direction is fragmentary.CV.s) However, one fact is fairly well established that the decomposition rate is enhanced considerably if the cyanoferrates are exposed to light.

The radiation chemistry of aqueous solutions of nitrous oxide

For carefully purified concentrated aqueous solutions of N 2 0, G (N 2 ) is initially greater than the steady state value of 3.0 and G (O 2 ) less than the steady state value of 1.45 when G (H 2 ) = G (H 2 O 2 ) = 0. For very dilute solutions G (N 2 ) is small, independent of dose rate and decreases with increasing dose and decreasing [N 2 O], while G (H 2 ) is initially &gt; 0.45, independent of dose rate and decreases with dose. The high initial G (H 2 is not due to organic or other impurity and is thought to arise either from bimolecular reaction of e aq − . and H within a spur or track or from unimolecular decomposition of the solvated electron either to H 2 + O - or H + OH - or from a combination of both. The dose effects are attributed to competitive scavenging of e aq − . by H 2 O 2 as the latter is produced.