SUBPICOSECOND STUDIES OF THE SOLVATION DYNAMICS OF FLUOROPROBE IN LIQUID SOLUTION

The dynamic Stokes shift of fluoroprobe in its lowest excited charge t ransfer state has been studied in a series of solvents, at room temper ature, with a time resolution of about 300 fs, Using the fluorescent u pconversion method dynamic Stokes shifts of up to 3000 cm(-1) have bee n resolved. The Stokes shift is attributed to the solvent response to the large photoinduced dipole moment of fluoroprobe (similar to 30 D) in the fluorescent charge transfer state. The solvation dynamics is de termined by the rotational diffusional motions of the ethereal solvent molecules.