The chemical and physical properties of ionic liquids depend on the combination of cations and anions, and the length of the alkyl chains and functional groups also have a significant effect on their properties. The preparation of functionalized ionic liquids is usually accomplished by introducing functional groups into the cations, including hydroxyl groups, amine groups, sulfonic acid groups, nitrile groups, ether groups, benzyl groups, carboxyl groups, ester groups, sulfhydryl groups, alkenyl groups, phosphate groups and the like.https://www.alfa-chemistry.com/products/functionized-ionic-liquids-150.htm