Electron photodetachment from [Fe(CN)6]4−: photoelectron relaxation and geminate recombination

The relaxation of photoelectrons detached from aqueous [Fe(CN)6]4− is captured via 50 fs pump-multicolor probe spectroscopy. The recovered relaxation (570 fs, 0.53 eV exponential spectral shifting due to solvation) is very similar to the electron dynamics subsequent to ionization of water, however the trapping time is slower (∼310 fs). The observed geminate recombination varies strongly with the effective charge on the photodetached species. The influence of the Coulomb potential is successfully unraveled from the recombination dynamics while extracting the average electron photoejection distance. In contrast to threshold detachment of monovalent anions, electrons are ejected to ∼15 Å.