The presence of solvent molecules in the vicinity of a solute affects a variety of processes in chemistry and biology, and thus one would like to have a physical picture of how solvation works. Although there are many structurally sensitive spectroscopic tools to investigate the role of solvent molecules in chemical processes, real time measurements of the dynamics of solvation had to wait for the development of pulsed laser spectroscopies with femtosecond time-resolution. This review describes applications of ultrafast spectroscopy to the study of solvation dynamics. At third order, we review resonant and non-resonant probes of solvation dynamics, with a focus on the study of simple and complex liquids. Fifth-order Raman spectroscopies are also reviewed, focusing on the insights these techniques give into the role of the solvent in chemical reactions and the anharmonic nature of the liquid state.
ultrafast; solvation; femtossecond; liquids
