Journal of Photochemistry最新文献_第5页

Laser-induced photoionization and single-strand break formation for polynucleotides and single-stranded DNA in aqueous solution: model studies for the direct effect of high energy radiation on DNA 水溶液中多核苷酸和单链DNA的激光诱导光电离和单链断裂形成:高能辐射对DNA直接影响的模型研究

Journal of Photochemistry Pub Date : 1987-07-01 DOI: 10.1016/0047-2670(87)80013-8

J. Opitz, D. Schulte‐Frohlinde

引用次数: 48

Excited State of Properties of 2-Phenylbenzthiazole and 3-Phenyl-1,2-Benzisothiazole 2-苯基苯并噻唑和3-苯基-1,2-苯并异噻唑性质的激发态

Journal of Photochemistry Pub Date : 1987-07-01 DOI: 10.1016/0047-2670(87)80006-0

D. Neckers, M. Sindler-Kulyk, J. Scaiano, L. C. Stewart, D. Weir

引用次数: 1

Photoconductivity measurement using a simulated electrostatic recording device 利用模拟静电记录装置测量光电导率

Journal of Photochemistry Pub Date : 1987-07-01 DOI: 10.1016/0047-2670(87)80014-X

N. S. Allen, E. T. Robinson, C. Stott, F. Thompson, D. C. Dobson, A. J. Nelson

引用次数: 5

Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homogeneous and micellar media II. Rate constants of fluorenone quenching by the leaving moiety 均相和胶束介质中模拟化学发光条件下苄基芴的臭氧分解2。芴酮被离去部分猝灭的速率常数

Journal of Photochemistry Pub Date : 1987-07-01 Epub Date: 2002-01-30 DOI: 10.1016/0047-2670(87)80008-4

L. Papalambros, J. Nikokavouras

{"title":"Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homogeneous and micellar media II. Rate constants of fluorenone quenching by the leaving moiety","authors":"L. Papalambros, J. Nikokavouras","doi":"10.1016/0047-2670(87)80008-4","DOIUrl":"10.1016/0047-2670(87)80008-4","url":null,"abstract":"<div>The rate constants for the quenching of the fluorenone fluorescence by substituted benzaldehydes and benzoic acids (substitutents: p-nitro, p-cyano, p-chloro, p-bromo, p-H, p-methyl, p-methoxy, p-methoxy-m-methyl, and p-dimethylamino) are reported in ethanolic and micellar media. These are compared with the diffusion rate constant and evidence is presented that, under chemiluminescence mimetic conditions, the quenching leaving moiety in close proximity to the emitter is responsible for most of the quenching observed. The binding constants and partition coefficients of the above compounds as well as those of the corresponding substituted 9-benzylidene fluorenes in cetyltrimethylammonium chloride are also reported together with quencher molecules per micelle. The influence of the micellar medium on the quenching rate constants is discussed and the position of the above compounds inside the micelle is reported.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"39 1","pages":"Pages 85-96"},"PeriodicalIF":0.0,"publicationDate":"1987-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)80008-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88174382","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}

引用次数: 0

Separation and identification of the products of the photodegradation of 7-amino-4-methylcoumarin and the mechanism of its photodegradation 7-氨基-4-甲基香豆素光降解产物的分离鉴定及其光降解机理

Journal of Photochemistry Pub Date : 1987-07-01 Epub Date: 2002-01-30 DOI: 10.1016/0047-2670(87)80012-6

Joy T. Kunjappu, K.N. Rao

{"title":"Separation and identification of the products of the photodegradation of 7-amino-4-methylcoumarin and the mechanism of its photodegradation","authors":"Joy T. Kunjappu, K.N. Rao","doi":"10.1016/0047-2670(87)80012-6","DOIUrl":"https://doi.org/10.1016/0047-2670(87)80012-6","url":null,"abstract":"<div>The separation of the products of the photodegradation of 7-amino-4-methylcoumarin (C120), a laser dye, has been achieved by a reverse phase high performance liquid chromatography method. Two reverse phase columns (C6 and ODS) were used to optimize the separation conditions and various mixtures of methanol and water served as the mobile phase. The chromatograms representing the separation of the photolyte from the photoproducts under various experimental conditions are also shown.The fluorescent photodegradation product in an oxygenated methanolic solution of the dye has been separated by column chromatography assisted by thin layer chromatography and high performance liquid chromatography. The structure of the compound has been ascertained by mass spectrometric and IR spectroscopic analysis and found to be 7-amino-3-hydroxy-4-methyl-coumarin. A mechanism is suggested for the formation of this product by the interaction of singlet oxygen and the dye. On the basis of the behaviour of the dye in degassed solutions, a general scheme is postulated to represent the photobleaching of C120.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"39 1","pages":"Pages 135-143"},"PeriodicalIF":0.0,"publicationDate":"1987-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)80012-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90021695","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}

引用次数: 9

Formation of methylanisole in the photolysis of chlorotoluene in methanol 氯甲苯在甲醇中光解过程中甲基甲苯的形成

Journal of Photochemistry Pub Date : 1987-07-01 DOI: 10.1016/0047-2670(87)80011-4

T. Ichimura, M. Iwai, Y. Mori

引用次数: 2

Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homegeneous and micellar media I: Kinetic law as a function of hammett's σ constants and quenching by the leaving moiety 均相和胶束介质中模拟化学发光条件下苄基芴臭氧分解I: hammett σ常数函数的动力学规律和残留部分猝灭

Journal of Photochemistry Pub Date : 1987-07-01 Epub Date: 2002-01-30 DOI: 10.1016/0047-2670(87)80007-2

L. Papalambros, J. Nikokavouras

{"title":"Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homegeneous and micellar media I: Kinetic law as a function of hammett's σ constants and quenching by the leaving moiety","authors":"L. Papalambros, J. Nikokavouras","doi":"10.1016/0047-2670(87)80007-2","DOIUrl":"https://doi.org/10.1016/0047-2670(87)80007-2","url":null,"abstract":"<div>A series of 9-(p-substituted) benzylidene fluorenes (p-nitro, p-cyano, p-chloro, p-bromo, p-H, p-methyl, p-methoxy, p-methoxy-m-methyl and p-dimethylamino) was synthesized and the rates of fluorenone production on oxidation with ozone were followed fluorimetrically (apparent rates) and spectrophotometrically (true rates). The rates were plotted against Hammett's σ constants and any quenching effect of the leaving moiety on fluorenone at the moment of their production was illustrated as deviation from the plot of the apparent rates. The above effect was intensified in micellar media as a result of a more rigid confinement of the two species inside the micelle, supporting an earlier suggestion that, in chemiluminescence, even a small degree of quenching of the primary emitter by the leaving moiety can be very effective as a result of their inherent proximity at the moment of their production.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"39 1","pages":"Pages 73-84"},"PeriodicalIF":0.0,"publicationDate":"1987-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)80007-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90033087","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}

引用次数: 1

Photophysics of pseudoazulenes: 7-azaindole derivatives 假氮杂烯的光物理性质:7-氮杂酚衍生物

Journal of Photochemistry Pub Date : 1987-07-01 Epub Date: 2002-01-30 DOI: 10.1016/0047-2670(87)80005-9

J. Waluk, B. Pakuła, S.J. Komorowski

引用次数: 4

Photocycloaddition of ketones to olefins as radiationless transitions 作为无辐射跃迁的酮到烯烃的光环加成

Journal of Photochemistry Pub Date : 1987-07-01 Epub Date: 2002-01-30 DOI: 10.1016/0047-2670(87)80002-3

Luís G. Arnaut, Sebastião J. Formosinho

引用次数: 4

Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homogeneous and micellar media III: Substituent effect in the micellar pseudophase 均相和胶束介质中模拟化学发光条件下的苯并芴臭氧分解III:胶束假相中的取代基效应

Journal of Photochemistry Pub Date : 1987-07-01 Epub Date: 2002-01-30 DOI: 10.1016/0047-2670(87)80009-6

L. Papalambros, J. Nikokavouras

{"title":"Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homogeneous and micellar media III: Substituent effect in the micellar pseudophase","authors":"L. Papalambros, J. Nikokavouras","doi":"10.1016/0047-2670(87)80009-6","DOIUrl":"https://doi.org/10.1016/0047-2670(87)80009-6","url":null,"abstract":"<div>The binding constants, mean occupation numbers per micelle, partition coefficients and per cent micellization of nine 9-(p-substituted) benzylidene fluorenes (p-nitro (i); p-cyano (ii); p-chloro (iii); p-bromo (iv); p-H (v); p-methyl (vi); p-methoxy (vii); p-methoxy-m-methyl (viii); p-dimethylamino (ix)) in cetyltrimethylammonium chloride and sodium dodecylsulphate were determined from the corresponding Stern—Volmer plots, with pyrene as the fluorescent probe. The ozonolysis reaction rates of the nine benzylidene fluorenes were measured in the micellar systems and, from the above partition coefficients together with the reaction rates in the bulk phase, the reaction rates in the micellar pseudophase, independent of the reaction rate in the bulk phase and the partition coefficient, were determined; the plots of these reaction rates (log ktr or log kapp) against Hammett's σ constants were linear.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"39 1","pages":"Pages 97-105"},"PeriodicalIF":0.0,"publicationDate":"1987-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)80009-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91702482","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}

引用次数: 1