Bond-breaking electron transfer of diatomic reactants at metal electrodes

A model Hamiltonian for concerted bond breaking and electron-transfer reactions at metal electrodes is presented; it combines elements of the Marcus theory, the Anderson-Newns model, and tight binding. The formalism is developed explicitly for the dissociation of a homonuclear diatomic molecule. A set of self-consistent equations for the densities of states of the reactants is derived, which allows the calculation of potential energy surfaces as a function of the molecular bond length and the generalized solvent coordinate. Model calculations have been performed both for the reduction and the oxidation of the molecule.