Proton transfer in a phenol-amine complex dissolved in a polar molecule nanocluster is shown in this video. The proton transfer rates and mechanisms, as well as solvation of the complex in the cluster, were studied using both adiabatic and nonadiabatic dynamics. The phenol-amine complex exists in ionic and covalent forms and as the size of the cluster increases the ionic form gains stability at the expense of the covalent form. Both the adiabatic and nonadiabatic transfer reaction rates increase with cluster size. Given a fixed cluster size, the stability of the covalent state increases with increasing temperature. The proton transfer rates do not change monotonously with an increase in temperature. A strong correlation between the solvent polarization reaction coordinate and the location of the phenol-amine complex in the cluster is found. The ionic form of the complex strongly prefers the interior of the cluster while the covalent form prefers to lie on the cluster surface. The ionic and covalent forms of the proton-phenol-amine complex are color coded and proton hops can be monitored by watching the state of the complex in the simulation.
H. Kim and R. Kapral, "Solvation and Proton Transfer in Polar Molecule Nanoclusters", J. Chem. Phys., 125, 234901 (2006).