80811-51-4Relevant academic research and scientific papers
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-Oxadiazolines
Csongar, Ch.,Socher, R.,Tomaschewski, G.
, p. 246 - 254 (2007/10/02)
The 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 ?p-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 title 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.
