Formation and investigation of unstable complex hydrides from tetrabutylammonium fluoride, water and SO2

Abstract

A phase separation occurred when SO₂ was introduced into the binary system of tetrabutylammonium fluoride (TBAF) and water system. The mechanics of this phase separation process were studied by Fourier transform-infrared spectroscopy (FT-IR), Raman spectroscopy and Karl-Fischer titration. A complex hydrides of TBAF–SO₂–H₂O was formed and the TBAF and SO₂ concentrated in the lower layer, and it could be released by heating the solution under reduced pressure (382.2 K, 10.1 kPa). The equilibrium solubility of SO₂ in the binary system of tetrabutylammonium fluoride and water was investigated. After desorption, the mixture could be reused to absorb SO₂. The effect of temperature and concentration of TBAF on the mole ratio of SO₂–TBAF and H₂O–TBAF of the triple hydrate was studied. The binary system of TBAF and water could absorb SO₂ efficiently.