Infrared study of the adsorption of methyl fluorosulphate vapour on the surface of magnesium oxide

Abstract

The adsorption of methyl fluorosulphate vapour onto magnesium oxide has been studied by infrared spectroscopy. Isolated surface hydroxyl groups form hydrogen bonds with adsorbed methyl fluorosulphate molecules. Slow chemisorptive interactions give MgOSO₂OMe groups and hydrogen fluoride, which itself reacts with the surface to give water and fluoride ions. Subsequent evacuation at high temperatures caused the decomposition of MgOSO₂OMe groups to MgOMe groups, sulphur trioxide, and surface sulphato complexes. The treated surface could be completely dehydroxylated by evacuation at lower temperatures than could the untreated pure oxide surface.