Abstract
We demonstrate herein a facile synthesis of a series of highly-ordered low-melting protic ionic liquids with linear C16–C20 side chains identical to natural fatty acids, which were produced by the S-alkylation of the 2-mercapto-1-methylimidazole (methimazole) ring. There is considerable structural latitude possible when designing highly lipophilic protic ionic liquids that exhibit low Tm values due to the cumulative disruptive effects of thioether and unsaturation on their packing efficiency. Their bulk thermophysical properties, hydrophobicity and cytotoxicity were also determined.