An adiabatic dynamical simulation study of the Zundel polarization of strongly H-bonded complexes in solution

We study, by an adiabatic dynamical simulation technique, a mixed classical-quantum model for strongly H-bonded complexes in polar solvents. The solvent influence on the adiabatic proton dynamics is interpreted in terms of a protonic polarization effect, usually referred to as the Zundel polarization. The relation to the solvent-induced proton transfer and the consequences on the broadening of the infrared absorption spectrum are discussed. We show that for increasing solvent-complex coupling, the system passes from an ‘‘oscillatory’’ to a ‘‘reactive’’ behavior, whereas the Zundel polarization passes from a familiar electronic-like regime to a saturated regime. In the latter case, a large band broadening, comparable to experimental observations, is obtained in the calculated infrared spectrum.