| Abstract
| - We calculated the proton-transfer rate constant from a super photoacid, 5,8-dicyano-2-naphthol (DCN2), toa protic solvent as a function of temperature. Previously, we found that the temperature dependence of theproton-transfer rate constant is explained as a continuous transition from nonadiabatic to solvent-controlledlimits. The model we used to calculate the proton-transfer rate constant is based on a diffusive propagationof the solvent configuration along a generalized solvent coordinate from the reactant potential surface towardthe crossing point with the product potential surface. The proton transfer occurs at the crossing point, and therate is calculated by a sink term placed at the crossing point. The sink term includes the solvent velocity andthe Landau−Zener transmission coefficient. Both the diffusion constant and the Landau−Zener transmissioncoefficient depend on the dielectric relaxation of the solvent. The calculations are compared with theexperimental data and an interpolation expression that bridges the nonadiabatic limit and the solvent-controlledlimit.
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