A high-pressure NMR investigation of reaction chemistries in a simple salt hydrate

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.