Investigating the Environment-dependent Photophysics of Chlorine Dioxide With Resonance Raman Intensities

The condensed-phase excited-state reaction dynamics of chlorine dioxide are investigatedusing resonance Raman intensity analysis. Absolute Raman intensities aremeasured on resonance with the 2 B 2 – 2 A 2 electronic transition and used to establish theexcited-state structural evolution which occurs on the 2 A 2 surface followingphotoexcitation. Analysis of the intensities demonstrates that excited-state relaxationoccurs along all three normal coordinates; however, only modest evolution is observedalong the asymmetric stretch. This limited relaxation stands in contrast to the extensivemotion along this coordinate in the gas phase. It is proposed that the initial excited-statestructural relaxation serves to define the symmetry of the reaction coordinate and thusthe mechanism of Cl production following photolysis of OClO.