Grotthuss mechanism

[1] Grotthuss envisioned the electrolytic reaction as a sort of ‘bucket line’ where each oxygen atom simultaneously passes and receives a single hydrogen ion.

It was an astonishing theory to propose at the time, since the water molecule was thought to be OH, not H2O, and the existence of ions was not fully understood.

Lemont Kier suggested that proton hopping may be an important mechanism for nerve transduction.

[12] [13] [14] The Grotthuss mechanism, along with the relative lightness and small size (ionic radius) of the proton, explains the unusually high diffusion rate of the proton in an electric field, relative to that of other common cations whose movement is due simply to acceleration by the field.

Some evidence from theoretical calculations, supported by recent X-ray absorption spectroscopy findings, has suggested an alternative mechanism in which the proton is attached to a "train" of three water molecules as it moves through the liquid.