@Article{JPhysChemA_101_8575, author = {J.-C. Gumy and E. Vauthey}, title = {{Investigation of the Excited State Dynamics of Radical Ions in the Condensed Phase Using the Picosecond Transient Grating Technique}}, journal= {J. Phys. Chem. A}, ISSN = {1089-5639}, volume= {101}, number= {46}, pages = {8575-8580}, url = {http://pubs.acs.org/doi/abs/10.1021/jp972066v}, doi= {10.1021/jp972066v}, abstract = {{A study of the dynamics of ground-state recovery of the perylene radical cation (Pe$^{•+}$), of perylene radical anion (Pe$^{•-}$), and of anthraquinone radical anion (AQ$^{•-}$) is reported. In boric acid glass, the excited-state lifetime of Pe$^{•+}$ is 35 ± 3 ps, while in concentrated sulfuric acid, it is smaller than 15 ps, the time resolution of the experimental setup. The excited-state lifetime of Pe$^{•+}$, Pe$^{•-}$, and AQ$^{•-}$ generated by photoinduced intermolecular electron-transfer reaction in MeCN is shorter than 15 ps. In the case of Pe$^{•-}$, the uncomplete ground-state recovery is ascribed to the occurrence of electron photoejection. The free ion yield in the intermolecular electron-transfer reaction between 9,10-dicyanoanthracene (DCA) and two electron acceptors was measured in a two-pulse experiment, where the second pulse excited the ensuing DCA$^{•-}$. This excitation has no influence on the magnitude of the free ion yield, indicating a short excited-state lifetime of DCA$^{•-*}$ relative to the time scale of back electron transfer and ionic dissociation. A red emission, ascribed to the fluorescence of protonated Pe, was detected in boric acid glass and sulfuric acid. No fluorescence that could be clearly ascribed to Pe$^{•+}$* could be observed.}}, year = {1997} }