Electron Photodetachment in Solution

The mechanism for photoejection of electrons from simple inorganic anions in aqueous solution is being explored using ultrafast UV pump - visible/IR probe spectroscopy in close connection with quantum simulations. The pathway for detachment in the prototype aqueous iodide system, excited with a single photon into the quasi-bound charge-transfer-to-solvent (CTTS) electronic state, is probed in detail. Our experiments observe, for the first time, the timescale of ejection of the electron into the solvent from the lowest CTTS state, and the subsequent relaxation of the solvent to accommodate and solvate the electron. The ejection process is compared with resonant detachment of the molecular anion [Fe(CN)6]4-. These low energy ejection pathways are contrasted with multi-photon ionization of solutes, or the solvent itself, into the conduction band.