title: Electron transfer within a reaction path model calibrated by constrained DFT calculations: application to mixed-valence organic compounds.
abstract: The quantum dynamics of electron transfer in mixed-valence organic compounds is investigated using a reaction path model calibrated by constrained density functional theory (cDFT). Constrained DFT is used to define diabatic states relevant for describing the electron transfer, to obtain equilibrium structures for each of these states and to estimate the electronic coupling between them. The harmonic analysis at the diabatic minima yields normal modes forming the dissipative bath coupled to the electronic states. In order to decrease the system-bath coupling, an effective one dimensional vibronic Hamiltonian is constructed by partitioning the modes into a linear reaction path which connects both equilibrium positions and a set of secondary vibrational modes, coupled to this reaction coordinate. Using this vibronic model Hamiltonian, dissipative quantum dynamics is carried out using Redfield theory, based on a spectral density which is determined from the cDFT results. In a first benchmark case, the model is applied to a series of mixed-valence organic compounds formed by two 1,4-dimethoxy-3-methylphenylene fragments linked by an increasing number of phenylene bridges. This allows us to examine the coherent electron transfer in extreme situations leading to a ground adiabatic state with or without a barrier and therefore to the trapping of the charge or to an easy delocalization.
authors.affiliation: Laboratoire Collisions Agrégats Réactivité, UMR 5589, IRSAMC, Université Toulouse III Paul Sabatier, Bât. 3R1b4, 118 route de Narbonne, F-31062, Toulouse, France. chris@irsamc.ups-tlse.fr and Laboratoire de Chimie Physique, UMR 8000, Université Paris-Sud, Bât. 349, 15 avenue Jean Perrin, F-91405 Orsay, France.
authors.forename: E
authors.initials: E
authors.lastname: Mangaud
authors.affiliation: Laboratoire de Chimie Physique, UMR 8000, Université Paris-Sud, Bât. 349, 15 avenue Jean Perrin, F-91405 Orsay, France.
authors.forename: A
authors.initials: A
authors.lastname: de la Lande
authors.affiliation: Laboratoire Collisions Agrégats Réactivité, UMR 5589, IRSAMC, Université Toulouse III Paul Sabatier, Bât. 3R1b4, 118 route de Narbonne, F-31062, Toulouse, France. chris@irsamc.ups-tlse.fr.
authors.forename: C
authors.initials: C
authors.lastname: Meier
authors.affiliation: Laboratoire de Chimie Physique, UMR 8000, Université Paris-Sud, Bât. 349, 15 avenue Jean Perrin, F-91405 Orsay, France and Département de Chimie, Université de Liège, Sart Tilman, B6, B-4000 Liège, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Desouter-Lecomte
mesh_terms: D004579:Electron Transport; D004583:Electrons; D008956:Models, Chemical; D009930:Organic Chemicals / Q000737:chemistry*; D011789:Quantum Theory; D013696:Temperature
chemical_list: D009930:Organic Chemicals