HYDROGEN-BONDING .52. IR SPECTRAL STUDY OF HYDROGEN-BONDING IN TETRAETHYLAMMONIUM HYDROXIDE TETRAHYDRATE AND TETRAETHYLAMMONIUM HYDROXIDE TRIHYDRATE

Tetraethylammonium hydroxide tetrahydrate and trihydrate are moderatel y stable, crystalline compounds. There is also a less stable pentahydr ate which loses H2O readily to yield the tetrahydrate. A tentative str ucture, based on IR spectra, is proposed for the trihydrate in which e ach oxygen atom is tricoordinate (neglecting hydroxy protons) and each OH- ion is connected to three other OH- ions by H2O...HOH bridges wit h the bridge H2O molecule further cross-linked by hydrogen bonds. The OH- ions do not act as hydrogen bond donors. Tetraethylammonium hydrox ide tetrahydrate is presumed to have a related structure, with the fou rth H2O molecule forming additional cross-links between bridges, thus generating two four-coordinate H2O molecules in the structure. Tetraet hylammonium hydroxide dihydrate and monohydrate cannot be prepared, as facile Hofmann elimination takes place on attempted dehydration of th e trihydrate.