Self-diffusion and Conduction in Hydrogen-Bonded Solids: Part 1.—Labile Proton Diffusion in Pivalic Acid

Abstract

A study has been made of the self-diffusion of labile protons in the plastic phase of pivalic acid using (CH3)3CCOO3H as the tracer. The carboxyl protons diffuse approximately 103 times more rapidly than the molecules and with a significantly different activation energy. Both differences arc confirmed by high-resolution n.m.r. measurements. Conductimctric measurements show that the proton migration is not accompanied by an equivalent charge transport. This leads to the conclusion that the proton migrates via an exchange mechanism which involves molecular rotation.