Results 201 to 210 of about 21,611 (258)
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Photoisomerization of Perfluoroaryltetrahedranes to Perfluoroarylcyclobutadienes
Journal of the American Chemical Society, 2011Two perfluoroaryl-substituted cyclobutadiene derivatives, 6 and 7, were prepared as air- and moisture-sensitive red solids by the photochemical isomerization of the corresponding tetrahedranes (4 and 5, respectively). Remarkably, the 9,10-dicyanoanthracene-sensitized photochemical reaction of 4 also proceeded, giving 6, and the mechanism of this ...
Yusuke, Inagaki +2 more
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Optimal Control of Photoisomerization
Physical Review Letters, 2005We report on optimal control of the photoisomerization of 3,3-diethyl-2,2-thiacyanine iodide dissolved in methanol. Enhancement and reduction of the relative yield of cis to trans isomers are achieved; i.e., the quantum efficiency of the photoisomerization is controlled with optimally phase and amplitude shaped 400 nm femtosecond laser pulses.
G, Vogt +4 more
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Photoisomerization kinetics of trifloxystrobin
Analytical and Bioanalytical Chemistry, 2005The photoisomerization kinetics of trifloxystrobin (TFS) in acetone under artificial sunlight is reported. HPLC analysis showed the TFS, a strobilurine fungicide of EE conformation, was converted into an equilibrium mixture of four isomers after illumination for 7 h.
Kaushik, Banerjee +2 more
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A New Photoisomerization of Bilirubin
Photochemistry and Photobiology, 1999AbstractPhotoirradiation of solutions of natural (4Z,15Z)‐biliru‐bin‐IXα in chloroform with ˜366 nm UV light leads rapidly to a new photoisomer that has been characterized by NMR spectroscopy and by its (ground‐state reaction) adducts with methanol and other protic nucleophiles. Unlike the previously described Z →E geometric isomeri‐zation important in
L, Cheng, D A, Lightner
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Photoisomerization of Phenylazoalkenes
Helvetica Chimica Acta, 1981Abstract(E)‐Phenylazocyclohexene (1) undergoes photoisomerization to s‐cis‐(Z)‐phenylazocyclohexene (2). Compound 2 reisomerizes to 1 at room temperature.
Joachim G. Schantl, Paul Margaretha
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Role of Viscosity Effect on Photoisomerization
International Conference on Luminescence - 1984, 1984Many rate processes like diffusion, dielectric relaxation, electron transfer reactions, nonradiative decay etc..., in dense media can be treated from a unified quantum statistical mechanical viewpoint [1]. In these unimolecular rate processes, one can regard that two potential surfaces, say a and b, are involved.
Villaeys, A. A. +2 more
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Photoisomerization of bentazone
Tetrahedron Letters, 1989Abstract Photolysis of bentazone 1 in non-polar solvents e.g. n-hexane yields the unexpected photoproduct 2 . On irradiation in methanol and in water 1-methylbentazone and anthranilic acid isopropylamide as a degradation product are observed.
Klaus Hustert, Mohammed Mansour
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The photoisomerization of dihydrocostunolide
Tetrahedron, 1976Abstract Photoisomerization of the germacranolid dihyrocostunolide (2) proceeds with a high degree of regio-and stereoselectivity to give the guaianolide photunolide (16) as the only major product. The conversion of photunolide to two guaianolides of known structure (8 and 9) and synthesis from O-acetylisophotosantonic lactone (11) provide ...
Rudolph E.K. Winter, Richard F. Lindauer
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Photoisomerization of Dihalomethanes
Angewandte Chemie International Edition in English, 1986Discovering a new type of reaction with simple molecules is not an everyday occurrence: The isomers 2, which are formed upon matrix irradiation of the haloiodomethane 1, can be regarded as unsolvated contact ion pairs equation image . In this rearrangement, the iodine atom migrates from the carbon atom to the halogen atom. The isomers 2a (violet), 2b (
Günther Maier, Hans Peter Reisenauer
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