Biological activity, solvation properties and microstructuring of protic imidazolium ionic liquids
Protic imidazolium ionic liquids (PILs) have shown great potential as regents and catalysts in liquid-phase chemistry. However, their biological activity/toxicity and solvation properties are rather understudied compared to those of more common aprotic ionic liquids (APILs). In this work, for the first time, we studied the cytotoxicity of nine chemically relevant imidazolium PILs with various alkyl side chains in the cation and compared it with the cytotoxicity of the corresponding aprotic analogues. The experimental data were supported by computational modeling. The results suggested the type of anion to be the major factor governing the cytotoxicity of the studied ILs with short alkyl side chains. Of note, even low-toxic PILs imposed considerable deleterious effects on eukaryotic cells when used as cryopreservation agents. According to a scanning electron microscopy (SEM) study, due to the weak amphiphilic properties of imidazolium cations with short alkyl side chains, the studied IL/water mixtures tended to produce simple solid hydrates rather than complex liquid systems with microdomain organization.
Reference: J. Mol. Liq., 2022, 367, 120450.
