ABSTRACT
The key role of the ionized hydrogen atoms (protons) in various chemical and biological processes was already well-known at the beginning of the 19th century when Theodor Grotthuss had proposed its famous theory for water conductivity. The proton bridge, basically, is a hydrogen-bond like supramolecular binding builds up by two atoms with high electronegativity where the positively charged proton becomes intercalated between the atoms. Depending on the orbital relaxation of the lone pair electron orbitals different potential energy surface (PES) profiles of a moving proton between two rigid electronegative atoms can form. The most important open question consists in the detailed theoretical description of the proton transfer mechanism from first electronegative atom to the second one when the potential energy surface on which the proton moves is far from the quadratic form and contains an energy barrier between the two minima.
