Abstract

Recent ultrafast OKE and photon echo experiments have shown that there is a strong correlation between the rates of simple chemical reactions and low frequency (50−100 cm⁻¹) librational modes present in polar solvents and proteins. However, no true microscopic identification of the relevant librational modes has been made as these experiments are only sensitive to the equilibrium solvent librational spectrum. Time-resolved far-IR (THz) spectroscopy is more suitable as it is in principle sensitive to the nonequilibrium dynamics of the solvent modes.¹ Such nonequilibrium experiments have been performed in our lab and we will present new experimental results as well as a theoretical analysis.

© 1997 Optical Society of America