International Journal for Radiation Physics and Chemistry最新文献

{"title":"The reaction of radiation-generated free radicals with cobalt(II) and cobalt(III) complexes containing macrocyclic ligands","authors":"A. Martin Tait ,&nbsp;Morton Z. Hoffman ,&nbsp;E. Hayon","doi":"10.1016/0020-7055(76)90042-5","DOIUrl":"10.1016/0020-7055(76)90042-5","url":null,"abstract":"<div><p>The reactions of radiation-generated free radicals with complexes of cobalt(III) and cobalt(II) containing the tetradentate 14-membered macrocyclic ligands 5,7,7,12,14,14 - hexamethyl - 1,4,8,11 - tetraazacyclotetradeca - 4,11 - diene (4,11 - dieneN₄), 5,7,7,12,12,14 - hexamethyl - 1,4,8,11 - tetraazacyclotetradeca - 4,14 - diene (4,14 - dieneN₄), and 2,3,9,10 - tetramethyl - 1,4,8,11 - tetraazacyclotetradeca - 1,3,8,10 - tetraene (1,3,8,10 - tetraeneN₄) have been studied in aqueous solution using pulse radiolysis. The cobalt(III) complexes can be reduced to cobalt(II) by e_aq⁻, CO₂⁻ and (CH₃)₂<span><math><mtext>Z.</mtext><mtext>̇</mtext></math></span>COH with the rate constants of the reactions depending upon the nature of the macrocycle and the axial ligand coordinated to the metal center. The rate constants and transient spectra arising from the reactions of the cobalt(II) species with H atoms, CH₃ radicals, and Br₂⁻ radicals have also been determined.</p></div>","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 6","pages":"Pages 691-696"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90042-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88554908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the decay of X-ray and U.V.-induced radicals in a methanol-water matrix at 113 K","authors":"Johan Moan","doi":"10.1016/0020-7055(76)90090-5","DOIUrl":"10.1016/0020-7055(76)90090-5","url":null,"abstract":"<div><p>The decay of <span><math><mtext>C</mtext><mtext></mtext></math></span>HO radicals in U.V.- and X-irradiated methanol-water matrices has been studied. The decay rate is not dose dependent in the dose range investigated (45–300 krad) and a certain fraction of the radicals are practically stable at 113 K. The decay is significantly different in X-irradiated and U.V.-irradiated samples. This is probably due to the existence of spurs in the X-irradiated samples.</p></div>","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 3","pages":"Pages 399-400"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90090-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90764642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermoluminescence isothermal decay in γ-irradiated CaSO4 : Dy phosphors—kinetics, and distribution of trap depths","authors":"O. Fiorella, M. Mangia, E. Oliveri","doi":"10.1016/0020-7055(76)90006-1","DOIUrl":"https://doi.org/10.1016/0020-7055(76)90006-1","url":null,"abstract":"","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"2 1","pages":"441-447"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87449061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diffusion kinetics of radical intermediates in radiation chemistry","authors":"W. Naumann, W. Stiller","doi":"10.1016/0020-7055(76)90002-4","DOIUrl":"https://doi.org/10.1016/0020-7055(76)90002-4","url":null,"abstract":"","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"22 1","pages":"407-415"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84476983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electron impact induced electronic excitation and molecular dissociation","authors":"L. Polak, D. Slovetsky","doi":"10.1016/0020-7055(76)90070-X","DOIUrl":"https://doi.org/10.1016/0020-7055(76)90070-X","url":null,"abstract":"","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"1 1","pages":"257-282"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90908798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Triplet states in radiolysis of solid solutions","authors":"M.V. Alfimov","doi":"10.1016/0020-7055(76)90059-0","DOIUrl":"10.1016/0020-7055(76)90059-0","url":null,"abstract":"<div><p>Results of studies carried out in this laboratory on radiolytic formation and deactivation of solute excited triplet states in rigid organic solutions are reviewed. Energy transport from matrix to solute molecules was shown to occur in these systems. In matrices formed by aromatic molecules (toluene, polystyrene) this energy transport is realized via processes of singlet-singlet and triplet-triplet transfer of excitation energy. Three processes of triplet quenching have been found and discussed: (i) transfer of electronic excitation energy to solvent radicals, (ii) annihilation of solvent molecular excitations upon interaction with solute triplet molecules and (iii) specific deactivation of solute triplet molecules by solvent radiation products.</p></div>","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 1","pages":"Pages 43-56"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90059-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91235249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deposition of radiation energy in solids as visualized by the distribution, structure and properties of alkyl radicals in γ-irradiated n-alkane single crystals","authors":"Tomas Gillbro,&nbsp;Anders Lund","doi":"10.1016/0020-7055(76)90033-4","DOIUrl":"10.1016/0020-7055(76)90033-4","url":null,"abstract":"<div><p>This paper summarizes results obtained earlier from E.S.R. studies of <em>γ</em>-irradiated <em>n</em>-alkane single crystals. It also contains some new experimental results that serve to give a more complete picture of the deposition of radiation energy in solid alkanes. The experiments performed with solid <em>n</em>-alkanes have thus far provided structural data that permit the nature and even the conformation of alkyl radicals to be clearly understood. Two types of radical exist, namely, one where the unpaired electron is located next to the end methyl group and one with the unpaired electron in the interior of the chain. The first type has a conformation which differs from that of the undamaged molecule. Microwave saturation data show that there is a difference in relaxation properties of these radicals which can be understood in terms of a difference in mobility. Relative yield measurements give the distribution of isomeric alkyl, the result differing from that obtained using product analysis in liquids. For protiated <em>n</em>-alkanes <em>n</em>-alkyl is lacking and the 2-alkyl concentration is higher than expected. For deuterated <em>n</em>-alkanes the E.S.R. spectrum is mainly that of radicals with the unpaired electron located in the interior of the carbon chain. This isotope effect is again contrary to observations in liquid <em>n</em>-alkanes.</p><p>The broad lines observed in protiated alkanes irradiated at 77 K and deuterated alkanes irradiated at 4.2 K are not believed to arise from strong spin-spin interactions. They are thought instead to arise from distorted crystal and radical structures relating to the damage regions of the crystals.</p><p>Radical pairs exist with different stability, yield and structure. Our estimate, in deuterated alkanes, that as much as 40% of the radicals are formed in pairs or clusters at 4.2 K shows that radical pair formation is an important radiolytic process in solid <em>n</em>-alkanes. Energy transfer from deuterated to protiated molecules has also been experimentally verified. This energy transfer is temperature dependent and occurs efficiently at 77 K, but less efficiently at 4.2 and 273 K. A relationship also exists for deuterated alkanes between the amount of radical pairs formed at 4 K and the long-range energy transfer at 77 K. This can be readily accounted for by an exciton transfer mechanism analogous to that in aromatic crystals. It might also be qualitatively described by a hydrogen abstraction process. In this case, however, the properties of the deuterium atoms are not understood.</p></div>","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 5","pages":"Pages 625-641"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90033-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76934402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The validity of diffusion concepts for describing the kinetics of recombination of an excess electron in liquid hydrocarbons","authors":"I.A. Boriyev,&nbsp;B.S. Yakovlev","doi":"10.1016/0020-7055(76)90015-2","DOIUrl":"10.1016/0020-7055(76)90015-2","url":null,"abstract":"<div><p>A comparison has been made of the experimental and calculated relative values of the efficiency of capture by the acceptor molecule of an electron generated by ionizing radiations (the α coefficient in Hummel's theory) in liquid hydrocarbons at room temperature; pentadecane, <em>n</em>-hexane, iso-octane and neopentane. For the experimental determination of the values of α the authors used the measurements of luminescence induced by a pulse of fast electrons in solutions of pyrene (10¹⁵−10¹⁶ cm⁻³) in hydrocarbons. Calculation of the values of α for the diffusion description of the process of recombination of an electron is based on the relation: <em>α</em>≈<em>K</em>_<em>S</em><em>r</em>_<em>m</em>^3/<em>u</em>, where <em>K_S</em> is the rate constant of capture of an electron by the molecule of pyrene; <em>u</em> is the drift mobility of the electron; <em>r_m</em> is the most probable distance of thermolysation of an electron. The values of <em>K_S</em> and <em>u</em> for pentadecane and neopentane were determined by investigation of the electrical conductivity induced by a pulse of fast electrons in solutions of pyrene; for <em>K_S</em> and <em>u</em> in the case of <em>n</em>-hexane and iso-octane and also for <em>r_m</em> the published data were used. It is shown that while for hydrocarbons with relatively low mobility of the electron the calculated and experimental values of α agree, for the hydrocarbon with the highest mobility of the electron (neopentane) use of diffusion concepts for the calculation gives an overstated value of α.</p></div>","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 4","pages":"Pages 511-512"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90015-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83301908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"World's leading nuclear scientists to convene November 14–19 in Washington, D.C.","authors":"","doi":"10.1016/0020-7055(76)90049-8","DOIUrl":"https://doi.org/10.1016/0020-7055(76)90049-8","url":null,"abstract":"","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 6","pages":"Pages 723-724"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90049-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136603664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gamma radiolysis of 3-methylpentane and ethanol glasses containing triphenylamine","authors":"S.C. Srinivasan,&nbsp;James E. Thean","doi":"10.1016/0020-7055(76)90027-9","DOIUrl":"10.1016/0020-7055(76)90027-9","url":null,"abstract":"<div><p>Gamma irradiation of a 3-methylpentane (3MP) glass containing triphenylamine (TPA) at 72–74K produces the trapped electron (e_3MP⁻) and another negative species (e_TPA⁻). Like e_TPA⁻ absorbs in the I.R. with a peak at 1.6 μm. In contrast with e_3MP⁻, e_TPA⁻ is not bleached by 1.9 μm light, has a narrower absorption band, and exhibits a broader E.S.R. singlet with <em>ΔH</em>_{<em>ms</em> = 6.6 G}. At 72K, the 100 eV yield, <em>G</em>(e_TPA⁻), increases with increase in TPA concentration and has the value 1.3 at 10⁻² mol dm⁻³ TPA while <em>G</em>(e_3MP⁻ decreases from 0.4 in neat 3MP to 0.1 at 10⁻² mol dm⁻³ TPA. Gamma irradiation of an ethanol glass containing TPA at 77K does not produce an infrared absorption but produces peaks at 440 and 410nm in addition to the trapped-electron peak at 540nm. The peaks at 440 and 410nm are attributed to TPA⁻ because absorbance at these peaks increases with increase in TPA concentration and that at 540nm decreases. The totality of the results for alcohol and 3-MP glasses suggests that e_TPA⁻ is an electron in a trap similar to that of e_3MP⁻ but modified by the presence of a TPA molecule whose positive nitrogen end is oriented toward the electron.</p></div>","PeriodicalId":100688,"journal":{"name":"International Journal for Radiation Physics and Chemistry","volume":"8 5","pages":"Pages 589-593"},"PeriodicalIF":0.0,"publicationDate":"1976-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0020-7055(76)90027-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90536551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}