Knowledge Bank

The chemical dynamics of simple photodissociation reactions in solution are currently of great interest as probes of condensed phase behavior. Picosecond Raman spectroscopy has been used to investigate the photodissociation and geminate recombination of l2 in a variety of solvents. The dynamics of vibrational cooling in the ground l2(X) electronic state have been observed with up to $8000cm-1$ of vibrational energy. These results are compared to molecular dynamics simulations of the energy dependence of V-T and V-V energy transfer mechanisms. Solvent cage dynamics have been investigated by monitoring transient vibrational bands arising from solvent molecules immediately surrounding the l2 solute. Transient heating in the solvent cage is observed to both appear and decay on the time scale of the 8ps laser pulse. This spectral technique provides a new method for obtaining detailed insight into the solvent environment immediately surrounding a reacting solute molecule.