Results 221 to 230 of about 14,703 (275)
Some of the next articles are maybe not open access.
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
openaire +2 more sources
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
openaire +2 more sources
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
openaire +2 more sources
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
openaire +1 more source
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
openaire +2 more sources
Photoisomerization of polybutadiene
Journal of Polymer Science Part C: Polymer Symposia, 1967AbstractPolybutadiene, in the solid state, and in the absence of added sensitizer, undergoes photochemical cis‐trans isomerization and loss of unsaturation when irradiated in vacua with krypton 1236 A. or mercury 2537 A. radiation. The estimated quantum yields for these two reactions are 0.25 and 1.53, respectively, for the krypton irradiations, and 0 ...
M. A. Golub, C. L. Stephens
openaire +1 more source
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
openaire +1 more source
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
openaire +1 more source
Photoisomerization of phenylisothiazoles
Journal of the Chemical Society D: Chemical Communications, 1970The photoisomerization of phenylisothiazoles into phenylthiazoles probably proceeds via tricyclic sulphonium cation intermediates.
Mamoru Ohashi +2 more
openaire +1 more source