Temperature dependence of the benzophenone anion solvation in 1-propanol

The solvation of the benzophenone anion in n-propanol over the temperature range −20 to −50°C was determined from the shift of the benzophenone anion absorption spectrum as a function of time. The anion spectra were the same as those determined at room temperature. The form of the kinetics is the same; the results at the different wavelengths are uniformly slower at lower temperatures. The activation energy for the anion solvation is approximately 22 kJ/mol. This value is greater than the value determined for dipole solvation so that, while benzophenone anion solvation is faster than excited state solvation at room temperatures, it is slower at lower temperatures.