ULTRAFAST DYNAMICS OF THE SOLVENT SOLUTE INTERACTION MEASURED BY FEMTOSECOND 4-WAVE-MIXING - LD690 IN N-ALCOHOLS

The fast dynamics of the oxazine dye LD690 in a series of n-alcohols are investigated using several techniques, including linear absorption, resonance Raman, and the femtosecond three-pulse photon echo. The systematic variation in the dynamics as one goes from methanol to 1-pentanol can be explained in terms of processes stationary on the femtosecond timescale (inhomogeneous broadening) and a fast process with a solvation correlation function M(t) = sech2(t/tau(C)) where tau(C) = 20 fs. The relative contributions of the fast and slow processes to the spectral broadening change as we increase the alcohol chain length.