Synthesis and Properties of Chiral Ammonium‐Based Ionic Liquids

Abstract

New chiral ammonium-based ionic liquids containing the (1R,2S,5R)-(-)-menthyl group can be easily and efficiently prepared under ambient conditions. The preparation and characterization of trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium salts is reported. The salts have been demonstrated to be air- and moisture-stable under ambient conditions and can be readily used in a variety of standard experimental procedures. The single-crystal X-ray structure of butyldimethyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride has been determined. The chiral, room-temperature ionic liquids have been characterized by physical properties such as specific rotation, density, viscosity, thermal degradation, and glass transition temperature. Trialkyl[(1R,2S,5R)-(-)-menthoxymethyl]ammonium chloride prototype ionic liquids have also been found to exhibit strong antimicrobial and high antielectrostatic activities.

Crystal structure of 1-benzyl-3-cyclododecyloxymethylimidazolium nitrate, [C23H35N2O]NO3]

“…Channels filled by chains of nitrate anion and parallel imidazolium rings are found. Similar structural elements occur in crystal structures of quaternary imidazolium chlorides [3,5,6] and also in crystal structures of quaternary imidazolium tetrafluoroborates, hexafluorophosphates and hexafluoroantimonates [4], The polar and non polar domains -sometimes called hydrophilic and lipophilic domains [5,6] -are found also in the structure of present compound. …”

Ionic Liquids Then and Now: From Solvents to Materials to Active Pharmaceutical Ingredients

“…In fact only recently, have specific ILs with biologically active ions been prepared and shown to retain their biological activity; specifically, IL salts of anti-bacterial quaternary ammonium cations were shown to be active against various types of bacteria and in some cases, an increased anti-bacterial effect was observed. [63][64][65][66] But ILs are composed of a minimum of two ions (a cation and an anion) and both may impart biological activity to the resulting salt. This dual functionality inherent in ILs is rarely exploited, 67,68 and we have only recently published our first paper with the designed incorporation of two biologically active ions into an IL.…”

New Eco-Friendly 1-Alkyl-3-(4-phenoxybutyl) Imidazolium-Based Ionic Liquids Derivatives: A Green Ultrasound-Assisted Synthesis, Characterization, Antibacterial Activity and POM Analyses

“…On the other hand, numerous studies have demonstrated the antimicrobial activity of various classes of ionic liquids against both environmental and clinically important microorganisms [28][29][30][31][32][33].…”