1H, 13C and 7Li nuclear magnetic resonance study of the lithium chloride–N,N-dimethylacetamide system

The complex solvent obtained by dissolving 5-10% of lithium chloride in N,N-dimethylacetamide (DMA) presents a good method for dissolving highly insoluble polymers, such as cellulose. ¹H, ¹³C and ⁷Li NMR spectroscopy have been used, together with viscosity and conductivity measurements, for the study of this complex solvent. The ¹H and ¹³C chemical shift variations of DMA, on increasing the lithium chloride concentration, are found to be in opposite directions. The T₁ relaxation times show a large decrease in the mobility of DMA in the presence of lithium chloride. Methyl-β-D -glucopyranoside has been used as a model for cellulose in order to investigate the mechanism of solution of this polymer. It was found that each hydroxy group of the solute interacts with one lithium chloride molecule in solution.