Mechanism of cellulose dissolution in the ionic liquid 1-n-butyl-3-methylimidazolium chloride: a 13C and 35/37Cl NMR relaxation study on model systems

13C and 35/37Cl NMR relaxation measurements on several model systems demonstrate that the solvation of cellulose by the ionic liquid (IL) 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) involves hydrogen-bonding between the carbohydrate hydroxyl protons and the IL chloride ions in a 1 ratio 1 stoichiometry.