Effects caused by external conditions on the inter-molecular proton transfer are considered. The quantum chemical calculations of the potential energies surface of the 2-(N-methyl-alpha-iminoethyl)-phenol molecule at presence of additional water or ethanol molecules are fulfilled. In vacuum the proton is predominantly localized at the oxygen atom, while the proton transfer to the nitrogen atom is substantially enhanced with the amount of water or ethanol molecules as a result of the hydrogen bond network. Additional external perturbation by the applied electric field does not make any substantial influence on the structural arrangement and the potential energy surface. (C) 2008 Elsevier B. V. All rights reserved.