One- and two-photon fluorescence anisotropy of selected fluorene derivatives
Abbreviated Journal Title
two-photon excitation anisotropy; steady-state fluorescence; transition; dipole moments; fluorene derivatives; HYDROCARBON REGION; CROSS-SECTIONS; EXCITATION; POLARIZATION; RELAXATION; ABSORPTION; MICROVISCOSITY; FLUOROPHORES; CHROMOPHORES; MOLECULES; Biochemical Research Methods; Chemistry, Analytical; Chemistry, Physical
The steady-state excitation anisotropy spectra of fluorene derivatives were measured in viscous solvents, under the one- and two-photon excitation, over a broad spectral range (UV-Visible). The orientation of their absorption transition moments for the first, S-0 --> S-1, and second, S-0 --> S-2, excited states were determined. It was shown experimentally that a decrease in the angle between S-0 --> S-1 and S-0 --> S-2 transitions corresponded to an increased value of two-photon absorption (2PA) cross section for these molecules. Two-photon excitation anisotropy was nearly constant over the spectral region investigated (in contrast to one-photon excitation anisotropy spectra) and can be roughly explained by a simple model of 2PA based on the single intermediate state approximation. For comparison, the same trend in two-photon excitation anisotropy was observed for Rhodamine B in glycerol.
Journal of Fluorescence
"One- and two-photon fluorescence anisotropy of selected fluorene derivatives" (2005). Faculty Bibliography 2000s. 4992.