A computational examination of the electric-field-induced proton transfer along the interface hydrogen bond between proton donating and accepting self-assembled monolayers

In order to investigate the possibility of the electric field control of proton transfer in the interface hydrogen-bond on self-assembled monolayer, we computationally evaluated the dependence of the potential energy curve along the proton transfer coordinate on the external electric field. It was demonstrated that the stable position of the proton can be switched from the hydrogen-bonding donor to acceptor according to the electric field, via the formation of the low-barrier hydrogen bond. By comparing with several hydrogen-bonding moieties from biomolecules, we confirmed that the switching threshold field is correlated with the pKa difference of the donor and acceptor.