A 19F magic angle spinning nuclear magnetic resonance and infrared analysis of the adsorption of alkali metal fluorides onto montmorillonite clay

Alkali metal fluorides have been adsorbed onto montmorillonite clay K10, and the resulting reagents analysed by 19F magic angle spinning nuclear magnetic resonance and infrared spectroscopy. The complexes M3SiF6, MAlF4, and M3AlF6 are readily formed, the particular complex depending on M, the loading, and the drying temperature employed. Chemisorption of fluoride to give surface -Si-F groups also occurs under certain conditions. Keywords: MAS NMR, alkali metal fluorides, adsorption, montmorillonite clay, infrared.