The potential energy curves for proton motion in the intermolecular hydrogen bonds in phenol-tertiary amine complexes have been analyzed to investigate the location of the energy minimum. The proton donor and proton acceptor properties of the complex components are the main parameters which determine the location of the minimum. Also substituent effect in phenols as well as the different proton acceptors can shift the potential energy curve for proton motion against the reaction coordinate. (C) 2009 Elsevier B.V. All rights reserved.