CC BY-NC-ND 4.0 UnportedKozari, EveSigalov, MarkPines, DinaFingerhut, Benjamin P.Pines, Ehud2022-01-142022-01-142021https://oa.tib.eu/renate/handle/123456789/7813https://doi.org/10.34657/6854Infrared (IR) absorption in the 1000-3700 cm-1 range and 1 H NMR spectroscopy reveal the existence of an asymmetric protonated water trimer, H7 + O3, in acetonitrile. The core H7 + O3 motif persists in larger protonated water clusters in acetonitrile up to at least 8 water molecules. Quantum mechanics/molecular mechanics (QM/MM) molecular dynamics (MD) simulations reveal irreversible proton transport promoted by propagating the asymmetric H7 + O3 structure in solution. The QM/MM calculations allow for the successful simulation of the measured IR absorption spectra of H7 + O3 in the OH stretch region, which reaffirms the assignment of the H7 + O3 spectra to a hybrid-complex structure: a protonated water dimer strongly hydrogen-bonded to a third water molecule with the proton exchanging between the two possible shared-proton Zundel-like centers. The H7 + O3 structure lends itself to promoting irreversible proton transport in presence of even one additional water molecule. We demonstrate how continuously evolving H7 + O3 structures may support proton transport within larger water solvates.enghttps://creativecommons.org/licenses/by-nc-nd/4.0/540CN stretchhydrated protonmolecular dynamics simulationstrimerZundel cationArticle