Solvent reorganization energies and local densities of Coumarin 153 (C153) in supercritical C2H6, CO2, and CHF3 (Tc=5 K) are measured using fluorescence spectroscopy. Reorganization energies are 320±70 and 770±70 cm-1 in CO2 and CHF3, respectively - nearly independent of density (0.3≤ρ/ρc≤2.1). The spectral shifts imply similar effective local densities in all three solvents. These effective densities can exceed 3-5 times the bulk density. In CO2 and CHF3, the maximum density augmentation calculated from emission shifts is ~20% greater than that calculated from excitation shifts. No such difference is found in C2H6.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry