Switching the Conductance of a Molecular Junction using a Proton   Transfer Reaction
  A novel mechanism for switching a molecular junction based on a proton transfer reaction triggered by an external electrostatic field is proposed. As a specific example to demonstrate the feasibility of the mechanism, the tautomers [2,5-(4-hydroxypyridine)] and {2,5-[4(1H)-pyridone]} are considered. Employing a combination of first-principles electronic structure calculations and Landauer transport theory, we show that both tautomers exhibit very different conductance properties and realize the "on" and "off" states of a molecular switch. Moreover, we provide a proof of principle that both forms can be reversibly converted into each other using an external electrostatic field. 
C. Hofmeister, R. H\"artle, O. Rubio-Pons, P. B. Coto, A. L.   Sobolewski, M. Thoss
cond-mat.mes-hall