Electron transfer reactions dynamically coupled to a dielectric medium: Orientational effects and bridge assistance

Abstract

A new treatment for studying electron transfer reactions is considered. The treatment allows for a detailed description of the electronic structure and is therefore appropriate for a complete description of weakly interacting electron transfer reactions. The initial state for the electron transfer system is selected by a variational scheme. The electron transfer is pictured to take place in an encounter complex consisting of the donor, the acceptor, and (optionally) a solvenubridge molecule. The electronic structure of the encounter complex is dynamically coupled to the surrounding solvent, and the direct time evolution of the electron transfer system is followed by a nonlinear time-dependent Hartree-Fock method. We present examples with benzeneanion radical as the donor, pyridine as the acceptor, and water as the bridgekolvent molecule. The general formalism appears to be a useful approach for studying electron transfer reactions in solution.

Molecular Response Method for Solvated Molecules in Nonequilibrium Solvation

“…In fact, few models for solving the time-dependent quantum mechanical equations for a molecular system coupled to a solvent exist. [34][35][36][37][38][39][40][41][42][43] Therefore, this article presents a novel method for treating nonequilibrium solvation states (the solvent is described as a dielectric medium), in conjunction with a recently established response method. 41 This involves solving the time-dependent response equations for a solvated molecule in a nonequilibrium solvation state due to an external, high-frequency perturbation.…”

“…The present article concerns the incorporation of the optical and inertial polarization vectors into the response methodology where the molecules are surrounded by a dielectric medium. The formalism is an extension of previous work [34][35][36][37][38][39][40] and X Abstract published in AdVance ACS Abstracts, May 1, 1996. generalizes the response formalism presented in ref 41 to handle nonequilibrium solvation states which occur during the application of external high-frequency laser fields to the solvated molecule.…”

Overtone spectroscopy of cis-propene-1,2-d2

“…The nature of this band will be discussed in section IV.A.2. Also visible in Figure 2a at 13 264 cm'1 is a shoulder that we were unable to assign definitively; however, potential assignments are combination bands involving any one of the five = 4 C-H stretch modes and two lower frequency modes. Both Fang et al16 and Wong and Moore6 reported two peaks in the methyl region of the = 6 level, but our spectrum of o -6 (not shown) clearly has four bands.…”

“…Charge rearrangement within a molecule or a complex of molecules has a self-consistent coupling to the solvent through the reaction field, and reaction field models have therefore attracted considerable interest in theoretical studies of the dynamics of electron-transfer reactions in molecular systems. 4,5 The recent generalization3 of the self-consistent reaction field (SCRF)4"6 method to general multiconfigurational reference states (MCSCRF) has, however, widened the scope of applications for studies of solvation effects on molecules since open-shell states with correlated wave functions can be included. Thus studies of solvation effects on systems other than closed-shell Hartree-Fock species, i.e., on molecular ions and radicals and on excitation and ionization processes as well as on…”

Long distance electron transfer

“…In a similar way the energy splitting A should be somewhat affected by the instantaneous polarization of solvent molecules close to the lone pairs had they been included in the calculation. A detailed discussion of the dynamical problem has been given by Mikkelsen et al [58,59].…”