Another in my GAMESS series on quantum chemistry. GAMESS is unquestionably a magnificent piece of work. All the people who have produced it should be very proud.
With the steady improvement of my skill using GAMESS, I was able to find the chemical reaction I was looking for in that earlier post. The basis set strongly influenced the reaction pathway in this one. Here is the transfer of a proton in water from one hydroxide to another.
I won’t talk a huge amount about this. The intent was simply to put up the pictures. This is the reaction by which protons are transferred around in water. This is the alkaline version of the reaction. I haven’t looked for it yet, but I suspect there is a homologous reaction under acidic conditions, involving hydronium only. It may be possible for this reaction to occur directly between hydronium and hydroxide, but I’m not sure there’s a stationary state possible in that system: the electrostatics will probably create a very steep potential energy gradient between the two molecules which may not have a stationary point in the middle (may depend on the solvent model to introduce screening).
The lesson: protons are probably never actually free in water.