Synthesis and characterization of protic ammonium based ionic liquids

Abstract

Ionic Liquids (ILs) have attracted extensive research interest in recent years as environmentally benign solvents and it has also been considered as the “engineering solvents” having its tunable physical and chemical properties. ILs are typically consist of organic nitrogen-containing heterocyclic/aliphatic cations and inorganic or organic anions. The ILs designed and synthesized for carrying out specified task are referred as functionalized ILs, which show great application potential in various processes. The efforts to produce functionalized ILs, characterized them, and evaluate their properties and applications are presented in this thesis.

A series of Seven (7) achiral and chiral protic diisopropylethylammonium based ILs were designed, synthesized and characterized. Out of these six are achiral, one is chiral based ILs. All diisopropylethylammonium based ILs were characterized by analytical data obtained from: FT-IR, UV-VIS, 1H-NMR spectroscopy.

Anti-microbial and toxicity studies were carried out using the well-diffusion technique with ILs solutions of two different concentrations. The six human pathogens were as follows: Bacillus cereus (+), Staphylococcus aureus (+), Sarcina lutea (+), Eschericia coli (-), Salmonella typhi (-), Pseudomonas aeruginosa (-).

Two protic Diisopropylethylammonium based ILs were chosen to employ in Mannich reaction to synthesis of β-amino carbonyl compounds and esterification reaction. The synthesized protic ionic liquids (PILs) showed catalytic effect on Mannich reaction and esterification reaction in very short time.

Keywords: Ionic liquids, Engineering solvent, Mannich reaction, β-amino carbonyl compound, Esterification reaction, Diisopropylethylammonium cation.