Lewis and Bronsted Acid Adducts in Ambient Temperature Chloroaluminate MoltenSalts: NMR Observations

摘要

A proton in acidic mixtures of ambient temperature chloroaluminate molten salts,composed of 1-ethyl-3-methylimidazolium chloride and aluminum chloride is a Bronsted superacid. The strength of this superacid can be modified by varying the underlying acidity of the molten salt. The study looks at the interaction of N, N-dimethylaniline (DMA) with the Lewis and Bronsted components of this superacid media by 13C and 1H NMR. The addition of DMA to an acidic melt results in the formation of the aluminum chloride adduct, DMA:AlC3. In the presence of a proton the AlCl3 is displaced in an equilibrium process to give a protonated DMA, DMAH+. The proton transfer of the DMAH+ is slow on the NMR time scale.