Femtosecond dynamics of photodetachment of the iodide anion in solution: resonant excitation into the charge-transfer-to-solvent state

The photodetachment of iodide ions in solution is probed via ultrafast spectroscopy with ∼50 fs time resolution. Excitation of I− is achieved with a single photon at 255 nm, populating the quasi-bound charge-transfer-to-solvent (CTTS) state. The detached electron is trapped by the solvent within 200 fs. Electron–iodine recombination is observed to take place on ∼25 ps timescale, but a reasonable fraction of electrons escape geminate recombination beyond 400 ps. The dynamics of electrons generated from the I− CTTS state are compared with those arising from two-photon ionization of the neat solvents.