Journal of Photochemistry最新文献_第10页

Kinetics and mechanism of the gas phase photochlorination of 1,2-dichloro-1,2-difluoroethylene 1,2-二氯-1,2-二氟乙烯气相光氯化反应动力学及机理

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87006-5

H.E. Di Loreto, E. Castellano

引用次数: 1

Ring contraction of cyclic olefins: chemical processes specific to electronically excited states? 环烯烃的收缩:特定于电子激发态的化学过程?

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87018-1

G. Collin, G. R. Maré

引用次数: 9

Photochemistry of phenylfulgides. XXII: Competing ultrafast radiationless deactivation, E-Z isomerization and electrocyclic ring-closure reactions 苯基氟化物的光化学。竞争超快无辐射失活，E-Z异构化和电环闭合反应

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87017-X

H.-D. Ilge, J. Sühnel, D. Khechinashvili, M. Kaschke

引用次数: 17

Singlet-oxygen reactions in cyanoaromatic-sensitized photo-oxidations 氰芳敏化光氧化中的单重态氧反应

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87012-0

Yi Cao, Bao Wen Zhang, Yang Fu Ming, Jian Xin Chen

引用次数: 10

Prototropism in aminophenols and anisidines: A reinvestigation 氨基酚类和茴香醚类化合物的向原性研究

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87022-3

Ranjit S. Sarpal, Sneh K. Dogra

{"title":"Prototropism in aminophenols and anisidines: A reinvestigation","authors":"Ranjit S. Sarpal, Sneh K. Dogra","doi":"10.1016/0047-2670(87)87022-3","DOIUrl":"https://doi.org/10.1016/0047-2670(87)87022-3","url":null,"abstract":"<div>The absorption and fluorescence spectra obtained in various solvents indicate that aminophenols and anisidines act as proton donors in ether and acetonitrile but as proton acceptors in methanol and water in the S0 state and as proton donors to all the solvents in the S1 state. Stretched sigmoid curves are observed for the equilibrium between the monocation and the neutral species for all the compounds, except p-aminophenol (pAMP) and p-anisidine, giving both ground state and excited state pKa values. For pAMP and p-anisidine, proton-induced fluorescence quenching of the neutral species is observed at moderate hydrogen ion concentrations. The values of the quenching constant are 3.3×109 dm3 mol−1 s−1 and 2.0×109 dm3 mol−1 s−1 for pAMP and p-anisidine respectively. The proton transfer reaction studied in methanol-water systems has indicated that, in low dielectric constant solvents, the excited state equilibrium is not established and thus the ground state pKa value is observed from fluorimetric titration curves.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"38 ","pages":"Pages 263-276"},"PeriodicalIF":0.0,"publicationDate":"1987-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)87022-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72260981","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: 16

General synthesis of new rose bengal derivatives with ether functional groups 具有醚官能团的玫瑰红-苯甲酰新衍生物的合成

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87030-2

Danian Xu , Adriaan Vanloon, Shwn-Meei Linden, D.C. Neckers

引用次数: 8

Solvent effects on the fluorescence properties of anilines 溶剂对苯胺荧光性质的影响

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87019-3

Gottfried Köhler

{"title":"Solvent effects on the fluorescence properties of anilines","authors":"Gottfried Köhler","doi":"10.1016/0047-2670(87)87019-3","DOIUrl":"https://doi.org/10.1016/0047-2670(87)87019-3","url":null,"abstract":"<div>Fluorescence spectra, quantum yields and lifetimes are comparatively studied for aniline, N,N-dimethylaniline (DMA) and some further alkylsubstituted and rigid aniline derivatives in various solvents. A good correlation of Stokes shift with macroscopic solvent parameters is found for DMA but not for aniline. General and specific solvent effects are distinguished by studying the functional dependence of various spectroscopic and photophysical parameters on the polar co-solvent concentration in binary solvent mixtures. Excited state complexation of primary and secondary amines with alcohols is demonstrated by the double-exponential decay of the monomer fluorescence and the grow-in of exciplex emission found in aniline—ethanol—n-hexane ternary systems. Exciplex formation is attributed to solvent—donor hydrogen bonding and primarily causes enhanced intersystem crossing compared with that in the free molecule, an effect also evoked by N-methylation. Non-specific long-range interactions give rise to a general reduction in the non-radiative deactivation rate, with the exception of o,o′-dimethyl-substituted anilines, for which an increase in this rate was found as the bulk becomes polar.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"38 ","pages":"Pages 217-238"},"PeriodicalIF":0.0,"publicationDate":"1987-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)87019-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72261015","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: 34

Equilibrium pK ∗ of carbazole studied by the deprotonation reaction in ammoniacal aqueous media 氨态水溶液中去质子化反应对咔唑平衡态pK *的研究

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87025-9

N. Chattopadhyay, M. Chowdhury

引用次数: 15

Caracteristiques photochimiques de quelques cetones polycycliques: Reactivite du cetene intermediaire 某些多环酮的光化学特性:中间酮的反应性

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87026-0

Hélène Brun, Gérard Perichet, Pierre Meallier, Bernard Pouyet

引用次数: 1

Photochemistry of phenylfulgides XXII: Competing ultrafast radiationless deactivation, E—Z isomerization and electrocyclic ring-closure reactions 苯磺酰亚胺的光化学XXII：竞争性超快无辐射失活、E-Z异构化和电闭环反应

Journal of Photochemistry Pub Date : 1987-06-01 DOI: 10.1016/0047-2670(87)87017-X

H.-D. Ilge, J. Sühnel , D. Khechinashvili, M. Kaschke

{"title":"Photochemistry of phenylfulgides XXII: Competing ultrafast radiationless deactivation, E—Z isomerization and electrocyclic ring-closure reactions","authors":"H.-D. Ilge, J. Sühnel , D. Khechinashvili, M. Kaschke","doi":"10.1016/0047-2670(87)87017-X","DOIUrl":"https://doi.org/10.1016/0047-2670(87)87017-X","url":null,"abstract":"<div>The photoisomerization about the αβ and γδ double bonds and the electrocyclic ring-closure reaction are competing processes within the excited singlet state of the phenylfulgides. Both processes are induced by the torsion of bulky molecular parts. Because of the extreme steric hindrance the torsion processes occur on potential curves without any activation barrier and consequently the photoisomerization, the photocyclization and the radiationless deactivation of the phenylfulgides are ultrafast processes proceeding within a few picoseconds, or even less, as the absorption measurements performed on a picosecond excite-and-probe beam spectrometer reveal. The competition between the E—Z isomerization and the cyclization is expressed by means of the partial quantum yields of these processes. The experimental results are interpreted in terms of the πbond orders and the sums of free-valence indices for the bondforming atoms in the S1 state calculated by the Pariser—Parr—People method.</div>","PeriodicalId":16771,"journal":{"name":"Journal of Photochemistry","volume":"38 ","pages":"Pages 189-203"},"PeriodicalIF":0.0,"publicationDate":"1987-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0047-2670(87)87017-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72206639","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: 17