Chemical Physics Letters, Vol.389, No.4-6, 427-432, 2004
Femtosecond dynamics of electron photodetachment of the fluoride anion in liquid water
The photoionization dynamics of aqueous fluoride after two-photon excitation at 310.5 nm is studied by pump-probe absorption spectroscopy. The initial population of the CTTS band is found to decay with a time constant of 380 fs to the lowest s-like charge transfer level. Out of this state with a lifetime of 430 fs, a rather long-lived atom-electron-water complex, (F:e(-))(solv) is formed. The quantum yield of the process is strongly suggested to be reduced by internal conversion to the fluoride ground level, eta(pair) similar to 0.5 to 0.7. Electron detachment to the final solvated electron competes with direct geminate recombination, so that 23% of the electrons return to the parent atom. (C) 2004 Elsevier B.V. All rights reserved.