Side reaction of cellulose with common 1-alkyl-3-methylimidazolium-based ionic liquids

Ionic liquids with 1-alkyl-3-methyl-imidazolium cations react at C-2 with cellulose at its reducing end, forming a carbon-carbon bond. The reaction is strongly catalyzed by bases, such as the commonly present impurities in ILs, imidazole. and 1-methylimidazole. The direct reaction was verified by means of C-13-isotopical labeling and with the help of an IL that carried a fluorescence label which was transferred to cellulose upon the reaction. In solutions of cellulose in alkylmethylimidazolium ILs, both the ionic liquid and the cellulose are evidently not inert. (C) 2008 Elsevier Ltd. All rights reserved.