Tetra-n-alkylammonium bisulphites: a new example of the existence of the bisulphite ion in solid compounds

Abstract

Liquid sulphur dioxide reacts with aqueous NR₄OH (R = Et, Buⁿ, or n-pentyl) solutions to form the corresponding bisulphite. I.r. studies indicate that the compounds contain the bisulphite ion with structure H–SO₃^–, having essentially C_3v symmetry. The preparative method used is that which leads to the formation of tetramethylammonium pyrosulphite when tetramethylammonium hydroxide is treated with sulphur dioxide. Tetra-n-propylammonium hydroxide, on treatment with sulphur dioxide, yields tetra-n-propylammonium pyrosulphite. The i.r. spectra of the tetra-alkylammonium bisulphites and pyrosulphites are recorded and discussed.