Data from: Microcanonical kinetics of water-mediated, long range proton transfer in microhydrated 4-aminobenzoic acid

We report the microcanonical kinetics of vibrationally-induced,
water-network-mediated proton transfer across the neutral acid scaffold,
4-aminobenzoic acid (4ABA), in isolated cationic clusters. Protonation of
neutral 4ABA occurs at the acid (O-protomer) and amine (N-protomer)
functionalities of 4ABA, yielding two distinct species whose relative
energies depend on the degree of hydration. Here we measure the rates of
intramolecular proton transfer in 4ABAH+·(H2O)6 ions upon
protomer-selective vibrational excitation of initially cold (6K) cluster
ions isolated in a cryogenic ion trap. Interconversion rates are observed
on the microsecond time scale. These results quantify the kinetics of
proton transfers in the context of a closed, finite system at well-defined
internal energies and therefore provide unprecedented experimental
benchmarks for theoretical efforts that are being developed to treat
relatively slow, highly cooperative solvent-mediated chemical processes.