Hydrogen bonding Part 30. New IR spectra-structure correlations for tetraethylammonium, tetramethylammonium, and N, N-dimethyl-pyrrolidinium fluoride monohydrates, tetraethylammonium chloride monohydrate, and tetramethylammonium hydroxide dihydrate; evidence for a planar (H 2O·F −) 2 cluster

Abstract

Tetraethylammonium chloride is not dimorphous, as we had once suspected; material recrystallized from hot acetone is identical to that prepared by Loehlin and Kvick by a different route, and contains a planar (H 2O·Cl −) 2 cluster of C 2h symmetry. Since the IR spectra of the water-fluoride cluster in tetraethylammonium and tetramethylammonium fluoride monohydrates are very similar to that of the water-chloride cluster in tetraethylammonium chloride monohydrate, we conclude that these hydrates contain a planar (H 2O·F −) 2 cluster, rather than the tetrahedral model previously proposed. IR spectra of N, N-dimethylpyrrolidinium fluoride monohydrate and monohydrate- d 2, demonstrate that they contain similar clusters. The crystal structure of tetramethylammonium hydroxide dihydrate has recently been reported, which allows a final correlation of the IR spectrum and the structure of this hydrate.