Transition-Metal-Free Synthesis of Perdeuterated Imidazolium Ionic Liquids by Alkylation and H/D Exchange



Economic, transition-metal-free syntheses of partially or completely deuterated imidazolium ionic liquids (ILs) were developed. Double alkylation starting from imidazole afforded side-chain deuterated imidazolium ionic liquids, which subsequently were fully deuterated by H/D-exchange on the cation ring. Isotopic exchange was studied for a range of ionic liquids, solvents and bases. Here, the presence of small amounts of basic impurities was found to significantly affect the exchange behaviour.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)