Caesium fluoride solutions in carboxylic acids

Abstract

The systems CsF–HCO₂H, CsF–MeCO₂H, CsF–EtCO₂H, and CsF–PrCO₂H have been investigated. The results show that the chemical shift of the carboxyiic proton, δ(OH), is dependent on the nature of the acid and varies with its pK_a. The i.r. spectra of saturated solutions and solvates, however, display two broad bands characteristic of hydrogen bonding at ca. 2 120 and ca. 1 550 cm^–1 which are independent of the acid. These arise from the very strong hydrogen bonding between the fluoride ion and the proton of a carboxyl group.