Primary Photophysical and Photochemical Processes in the Photolysis of 1,2-Dihydroquinolines in Different Solvents
- 26 Downloads
The fluorescence lifetimes (τfl) of alkyl and alkoxy substituted dihydroquinolines (DHQ) were measured in hexane, isopropanol, methanol, and water. It was shown that τfl was determined by the solvent nature and weakly depended on substituents on the DHQ aromatic ring and heterocycle, with τfl being substantially lower in methanol than in the other solvents. The decrease in τfl in MeOH is caused by an increase in the rate constants of the photochemical reaction and nonradiative transitions in this solvent. The quantum yield of fluorescence in H2O and MeOH, in which the photoinduced addition of the solvent molecules occurs, decreases with a decrease in the excitation wavelength within the limits of long-wavelength absorption band, thus providing strong evidence that the photochemical reaction proceeds from the unrelaxed excited state.
KeywordsMethanol Hexane Excited State MeOH Isopropanol
Unable to display preview. Download preview PDF.
- 1.Nekipelova, T.D., Kurkovskaya, L.N., Levina, I.I., Klyuev, N.A., and Kuzmin, V.A., Izv. Akad. Nauk, Ser. Khim., 1999, no. 11, p. 2072.Google Scholar
- 2.Nekipelova, T.D., Shishkov, V.S., and Kuz'min, V.A., Khim. Vys. Energ., 2002, vol. 33, no.3, p. 212 [High Energy Chem. (Engl. Transl.), 2002, vol. 33, no. 3, p. 177].Google Scholar
- 4.Nekipelova, T.D., Malkin, Ya.N., and Kuz'min, V.A., Izv. Akad. Nauk SSSR, Ser. Khim., 1980, no. 1, p. 80.Google Scholar
- 6.Nekipelova, T.D. and Shishkov, V.S., Khim. Vys. Energ., 2004, vol. 35, no.5, p. 355 [High Energy Chem. (Engl. Transl.), 2004, vol. 35, no. 5, p. 301].Google Scholar
- 7.Malkin, Ya.N. and Kuzmin, V.A., Usp. Khim., 1985, vol. 54, no.11, p. 1769.Google Scholar
- 8.Malkin, Ya.N. and Makarov, S.P., Izv. Akad. Nauk SSSR, Ser. Khim., 1985, no. 6, p. 1282.Google Scholar
- 9.Knoevenagel, E., Ber. Dtsch. Chem. Ges., 1921, vol. 54, p. 1723.Google Scholar
- 11.Kovalenko, N.P., Sheck, Yu.B., and Alfimov, M.V., J.Lumin., 1977, p. 157.Google Scholar