SOLVENT-ELECTRONIC STATE INTERACTIONS MEASURED FROM THE GLASSY TO THE LIQUID-STATE .1. ULTRAFAST TRANSIENT AND PERMANENT HOLE BURNING IN GLYCEROL

Picosecond transient and permanent hole burning spectroscopies are used to study the interaction between glycerol and the electronic states of the nonpolar solute dimethyl-s-tetrazine. Variable temperature measurements from the low temperature glass into the fluid region have identified a phonon-modulated interaction in agreement with a previous hypothesis [J. Chem. Phys. 94, 5787 (1991)]. However, this mechanism alone cannot account for the magnitude of the subpicosecond line broadening seen at room temperature. A second relaxation mechanism is identified, which is connected to the structural coordinates involved in the glass transition and reaches subpicosecond relaxation times at room temperature.