Fluorescence anisotropy of indole molecules under two-photon excitation in the spectral range of 485–510 nm
- 23 Downloads
Decay of polarized fluorescence in indole dissolved in propylene glycol under two-photon excitation by femtosecond laser pulses in the wavelength range of 485–510 nm has been studied. It is shown that under the experimental conditions used the fluorescence decay signal can be well described by a single excited state lifetime τf and a single rotation diffusion time τrot. By processing the data obtained, the times τf and τrot as well as anisotropy parameter r 0 characterizing the symmetry of two-photon excitation of indole molecules have been determined. Decreasing of the anisotropy parameter r0 down to zero under two-photon excitation energy higher than 5.1 eV has been observed. Interpretation of the obtained results have been done on the basis of ab initio quantum-mechanical computations. A model of energy relaxation under the condition of twophoton excitation of indole in a polar solvent has been discussed.
Unable to display preview. Download preview PDF.
- 9.J. R. Lakowicz, Topics in Fluorescence Spectroscopy: Nonlinear and Two-Photon-Induced Fluorescence (Springer Science, New York, 1997), Vol. 5.Google Scholar
- 17.R. P. Wayne, Principles and Applications of Photochemistry (Oxford Univ. Press, Oxford, 1988).Google Scholar
- 18.Gaussian 03, Rev. E.01 (Gaussian Inc., Wallingford, CT, 2004).Google Scholar