SUBPICOSECOND FLUORESCENCE STUDY OF THE LDS-751 DYE MOLECULE IN ETHANOL

A time-dependent fluorescence Stokes shift study of the LDS 751 (styry l 8) dye molecule in ethanol solution is presented. Fluorescence inten sity curves were recorded with sub-picosecond time resolution at vario us wavelengths using the fluorescence upconversion method. From the ex perimental curves, time-resolved fluorescence spectra have been recons tructed, allowing the calculation of the spectral shift correlation fu nction c(t) = [vBAR(t) -vBAR(infinity)]/[vBAR(0) -vBAR(infinity) ]. We find c(t) of LDS 751 in ethanol at room temperature to be well descri bed by a monoexponential function with a 1/e time of 5 +/- 1 ps.