Photoionization-induced proton transfer dynamics in the phenol-ammonia complex has been studied by using femtosecond photoionization-photofragmentation spectroscopy. Neutral phenol-ammonia complex prepared in a free jet is photoionized by a femtosecond laser pulse via [1+1] resonance-enhanced multiphoton ionization using phenol as the chromophore, and the subsequent relaxation dynamics is probed with a delayed pulse. Phenol monomer and phenol-water complex were also studied for comparison. The results revealed that, even though the initial proton-transfer motions are ultrafast and impulsive, the complex takes a relatively long time (~45 ps) to stabilize into the equilibrium PT structure by dissipating the energy initially localized in the O�H�N region to other modes of the system. This conclusion suggests that, during an acid-base reaction, the intermolecular proton transfer motions are weakly coupled to the intramolecular modes.

Ultrafast photoionization-induced proton transfer in phenol-ammonia complex

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.