Charge transfer and thermodynamic properties of electrostatically coupled chains

Abstract

A model of donor and acceptor molecular chains coupled by electrostatic interactions is investigated. The temperature dependence of the charge transfer between the chains as well as the thermodynamic properties such as the paramagnetic spin susceptibility and the specific heat are calculated. Our models consist of one-dimensional donor and acceptor molecular chains, each being described by either a simple tight-binding band or a strongly correlated Hubbard model. The intermolecular electrostatic interactions are treated within the mean-field approximation. We find that under certain conditions, there is a discontinuity in the charge transfer as temperature changes. Also, the effects on the charge transfer due to the finite bandwidth of a tight-binding band are found to be quite different from those due to the finite bandwidth of a strongly correlated Hubbard band.