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Photosensitized Cycloreversion of Cage Compound via Triplet Energy Transfer

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chinese chemical Letters 1996年第9期7卷 794-796页

作者： tung, ch Ying, YM chINESE ACAD SCI INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA

Several triplet sensitizers were found to be able to photosensitize cycloreversion of the photodimer (1) of methyl naphthalene-2-carboxylate. With the increase of the donor's triplet energy, the quantum yield of the i... 详细信息

关键词： Photosensitized Cycloreversion of Cage Compound via Triplet Energy Transfer

Semiconductor photoinduced cycloreversion of the dimer of methyl 2-naphthoate

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chinese Journal of chemistry 1997年第3期15卷 260-264页

作者： tung, ch Ying, YM Institute of Photographic chemistry Chinese Academy of Sciences Beijing 100101 China [*]Institute of Photographic chemistry Chinese Academy of Sciences Beijing 100101 China

The dimer of methyl 2-naphthoate (I) has been found to undergo efficient cycloreversion to its monomer, methyl naphthalene-2-carboxylate (2) on illuminated ZnO and TiO2 but not on CdS. An electron transfer and cation radical chain mechanism is proposed. Quantum yields, solvent effect. the role of oxygen, and the quenching of the reaction were investigated, and were consistent with the proposed mechanism.

关键词： semiconductor photoinduced cycloreversion electron transfer

Photophysical Behaviors of Azobenzene in Solvent-Swollen Nafion Membranes

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chinese chemical Letters 1996年第10期7卷 944-947页

作者： Guan, JQ tung, ch ACAD SINICA INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA

The fluorescence from azobenzene (AB) molecule incorporated into water-swollen Nafion in acid form was observed at room temperature for the first time. The incorporation process was investigated by UV absorption. The plot of the concentration of AB in Nafion vs. the soaking time shows that the adsorption process is diffusion-controlled, and the apparent diffusion coefficient (D) was determined to be 7.6x10(-10) cm(2)s(-1). These results are attributed to the fact that AB molecules are located in the fluorocarbon/water interface of the Nafion membranes and are protonated. In methanol-swollen Nafion membranes, AB fails to fluoresce because it is located at the methanol pool enclosed by the cluster networks.

关键词： Photophysical Behaviors of Azobenzene in Solvent-Swollen Nafion Membranes

ENHANCEMENT　OF　INTRAMOLECULAR　EXCIMER　FORMATION　AND　PHOTODIMERIZATION　OF　POLYETHERS　BEARING　NAPHTHALENE　chROMOPHORES　VIA　COMPLEXATION　WITH　CATIONS

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chinese chemical Letters 1995年第2期6卷 113-116页

作者： tung, ch Wu, LZ Acad Sinica Inst Photog Chem Beijing 100101 Peoples R China

The fluorescence spectra and photodimerization of naphthalene end-laballed poly(ethylene glycol) oligomers (N-Pn-N) in methanol in the prescence of alkali cations have been investigated. The ion enhances or inhibits intramolecular excimer formation and photodimerization of N-Pn-N, depending on the size of the ion and the length of the polyether chain. This observation suggests that the polyether chain binds the ion, thus adopts a crown ether-like conformation.

关键词： VIA chROMOPHORES COMPLEXATION WITH NAPHTHALENE AND BEARING

The Transient Time-Resolved Absorption Spectra of 1-Naphthylacetic Acid

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chinese chemical Letters 2000年第3期11卷 261-262页

作者： Li, W tung, ch Ye, JP chinese Acad Sci Inst Photog Chem Beijing 100101 Peoples R China

The transient absorption spectra of 1-naphthylacetic acid in tetrahydrofuran have been obtained by laser flash photolysis technique. The transient species bands are at 509, 535 and 553 nm. These peak intensities incre... 详细信息

关键词： transient spectra laser chemistry 1-naphthylacetic acid

Photoisomerization of norbornadiene group in a rigid bichromophoric compound initiated by remote keto chromophore: long-distance through-bond triplet energy transfer

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chinese Journal of chemistry 1996年第4期14卷 377-380页

作者： tung, ch Zhang, LP Li, Y chINESE ACAD SCI INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA

A diad compound 3 beta(bicyclo[2,2,1]hepta-2,5-diene-2-methylcarboxylate-3-carboxy)-androst-5-en-17-one (NBD-S-ONE) was synthesized and its photochemistry was examined. Irradiation of NBD-S-ONE in acetonitrile at lambda > 300 nm selectively excited the keto chromophore. After intersystem crossing, the triplet energy of the keto group was transferred to the NBD group with 18.6% efficiency via a through-bond mechanism, resulting in the isomerization of the latter group to the quadricyclane group.

关键词： norbornadiene photoisomerization through-bond triplet energy transfer

Synthesis and Study of Two-Photon Induced Fluorescence of Novel Dyes

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chinese chemical Letters 1999年第12期10卷 0-0,0-0页

作者： Wu, LZ Tang, XJ Jiang, MH tung, ch chinese Acad Sci Inst Chem Ctr Mol Sci Beijing 100080 Peoples R China chinese Acad Sci Inst Photog Chem Beijing 100101 Peoples R China Shandong Univ Inst Crystal Mat Jinan 250100 Peoples R China

The synthesis and upconverted fluorescent properties of three novel organic compoundswith the structure: donor/bridge/acceptor are reported. The dyes show strong upconvertedfluorescence.

关键词： Two-photon upconveFted fluorescence synthesis of new dyes.Recived##8 22 July 1999

Interaction　of　Polyelectrolyte　with　Fluorocarbon　Surfactant　in　Aqueous　Solution

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chinese chemical Letters 1996年第10期7卷 951-953页

作者： Wang, YZ Ji, HF tung, ch Yue, GC ACAD SINICA INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA JILIN UNIV DEPT ENVIRONM SCICHANGCHUN 130023PEOPLES R CHINA

The variation of the I1/I3 ratio of the fluorescence of pyrene in polystyrene-based quaternary ammonium salt (PA) and sodium carboxymethylamylose (NaCMA) aqueous solutions was measured as a function of sodium perfluorooctanoate (SPFO) concentration. Association of the anionic fluorocarbon surfactant with cationic polyelectrolyte (PA) to form mixed micelles occurred at the surfactant concentrations far below its normal critical concentration, while no interaction between SPFO and anionic polyelectrolyte (NaCMA) was detected. The driving force for the formation of mixed micelles of *** PA is electrostatic interactions.

关键词： Aqueous Surfactant Fluorocarbon Polyelectrolyte Interaction

PHOTOchEMISTRY　OF　SUBSTITUTED　PHENYL　PHENYLACETATES　WITHIN　CYCLODEXTRIN　CAVITIES

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chinese chemical Letters 1995年第1期6卷 27-30页

作者： tung, ch Ying, YM Yang, ZQ Wang, XH chinese Acad Sci Inst Photog Chem Beijing 100101 Peoples R China

The photochemical reactions of several substituted phenyl phenylacetates incorporated in the cavities of α-and β-cyclodextrins and in organic solvents were investigated. Photolysis of these esters in organic solutions resulits in both photo-Fries rearrangement and photodecarbonylation ***, the esters included in cyclodextrin cavities almost exclusively undergo photo-Fries ***, in the photo-Fries reactions of the inclusion complex the ratios of ortho to para rearrangement products are evidently increased compared with those in organic solutions. Those are good exampleg for using cyclodextrins to control the selectivity in photochemical reactions.

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