Dinh Quan Nguyen

Ionic liquid-assisted carboxylation of amines by CO2: a mechanistic consideration

The catalytic roles of ionic liquids (ILs) in the syntheses of 1,3-disubstituted ureas from the carboxylation of amines by CO(2) were experimentally and theoretically investigated. The carboxylation reaction of n-butylamine was greatly facilitated by the presence of an IL and the catalytic activity of the IL was strongly affected by the nucleophilicity of the anion. Computational study on the mechanistic aspects of the carboxylation with methylamine with or without the presence of an IL, 1-ethyl-3-methylimidazolium chloride, implies that the activation energies of the transition states and the intermediate ionic species could be lowered significantly through the multi-interactions of the carbonyl group of CO(2) with both cations and anions of the ILs.

Multi-functional zwitterionic compounds as new membrane materials for separating olefin–paraffin mixtures

Various types of multi-functional zwitterionic compounds containing both ester and sulfonate groups were prepared and their silver nitrate salts were tested as carriers for facilitated olefin transport membranes in the separation of ethylene–ethane and propylene–propane mixtures. Ester group-containing multi-functional zwitterionic silver compounds exhibited much higher performances in comparison with methyl group-containing zwitterionic compounds. A FT-IR study showed that ester-containing zwitterionic compounds interact with silver ions through both sulfonate and ester functional groups.