Abstract

A major aim of time-resolved spectroscopies is the characterization of chemical reaction intermediates to get real-time information on reaction mechanisms. The most obvious approach to time dependent molecular processes is the short time application of an external perturbation and observation of the subsequent changes in time by spectroscopic techniques. To a chemist, the structural evolution of the reactants along the reaction pathway is one of the defining reaction characteristics. Determining the geometry of reaction intermediates is thus essential but their short lifetimes preclude the application of classical diffraction techniques. Time-resolved vibrational spectroscopies are suitable for providing structural information on short-lived species. We utilize time-resolved Raman scattering to study photochemical processes in solution. In this case the reaction is initiated by a short laser pulse (pump pulse) and the structural evolution is monitored by analyzing the transient vibrational Raman spectra excited with a second laser pulse (probe pulse) as a function of the pump-probe time delay.

© 1998 IEEE