ISSN:
0021-8383
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Photochemistry of Arylsubstituted Δ2-1,3,4-Oxadiazolines. II. The Influence of the Substituents and the Solvent on the Absorption and Fluorescence Properties of Arylsubstituted Δ2-1,3,4-OxadiazolinesThe electronic absorption and the fluorescence spectra of 16 arylsubstituted Δ2-1,3,4-oxadiazolines were measured in benzene at room temperature.The push-pull effect of the substituents supports an increasing intramolecular charge-transfer in the electronically excited singlet state, which increases its dipole moment relative to the ground state.The significant linear correlation of the Hammett σp-values with the energies of the fluorescence and absorption maxima of the Δ2-oxadiazolines, p-substituted in the phenylring at the C 2-atom, demonstrate these intramolecular charge transfer.The titel compounds demonstrate with increasing solvent polarity a bathochromic shift of the absorption maxima.For some oxadiazolines the dipole moment for the excited singlet state proved to be about 30 Cm as Stoke's shift dipendency from the solvent indicate.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prac.19823240209
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