Cholesterol-based simple supramolecular gelators: an approach to selective sensing of CN- ion with application in dye adsorption

摘要

Cholesterol-linked simple supramolecular gelators 1-3 with functional diversity have been designed on 4-hydroxybenzaldehyde backbone for anion sensing through gel-to-sol methodology. Change in functional group in the gelators of common structural feature has significant impact on gelation, gel properties, morphology and anion sensing behavior. The dicyanovinyl derivative 3 has been established as superior gelator among the three as it forms gel from varieties of solvents with lowest concentration. All the three gels are applied in anion recognition. The gel state of 1 remains virtually intact in presence of all the anions tested. The oxime derivative 2 interacts with basic anions like CN-, F- and AcO- and displays no selectivity in gel phase anion sensing. On contrary, the dicyanovinylated analogue 3 shows gel-to-sol transition selectively in presence of CN- and validates its visual sensing. Additionally, the gel of 3 as explored in dye adsorption works well in rapid removal of crystal violet, a cationic dye from waste water.