High conductivity and phase transitions of tetramethylammonium hydroxide pentahydrate, (CH 3) 4NOH·5H 2O

Abstract

A clathrate hydrate, tetramethylammonium hydroxide pentahydrate was found to be a fast “proton” or “hydroxide ion” conductor, about 5×10 −3 S cm −1, for the room temperature phase (phase III). The high temperature phase (phase I) has body-centered cubic symmetry and high conductivity comparable to the liquid phase. Details of the mediate phase (phase II) are ambiguous.