PNNL

Abstract

Ionic liquids are currently being used in combination with supercritical fluids for catalytic reactions due to the ease of extraction of reaction products by fluids from such bi-phasic systems. In this investigation we report interesting chemistry involving a simple salt hydrate, tetramethylammonium fluoride tetrahydrate, [(CH3)4N]F·4H2O, as a neat melt and dissolved in methanol in contact with supercritical and subcritical CO2. This hydrate is proposed as a simulant for more complex ionic liquids, to investigate any potential secondary reaction chemistry in these solvent systems with carbon dioxide. Evidence is presented for the formation of methylcarbonate, CH3O(C=O)O-, and fluoromethane, CH3F, in solution when the salt hydrate is in contact with methanol and CO2. Keywords: salt hydrate, ionic liquid, supercritical fluids, high-pressure NMR, methylcarbonate