Chemical Reaction Dynamics in Liquid Solutions

The dynamics of bimolecular chemical reactions can be examined in liquid solutions using infrared absorption spectroscopy with picosecond time resolution. On such short time scales, the transient absorption spectra reveal vibrational mode and quantum-state-specific energy disposal, followed by vibrational relaxation as the energy is dissipated to the surrounding solvent. Comparison with energy disposal measurements for gas-phase reactions under single-collision conditions offers direct insights into the modification of the energy landscape and the nuclear dynamics in the presence of the solvent. The reactions of CN radicals with organic molecules in chlorinated solvents exemplify the dynamical information that can be obtained. The potential to extend such experiments to a range of reactions and solvents is discussed.