Cholesterol appended bis-1,2,3-triazoles as simple supramolecular gelators for the naked eye detection of Ag+, Cu2+ and Hg2+ ions

Cholesterol coupled bis-1,2,3-triazoles 1-3 have been synthesized and their gelation abilities are examined. Bis triazoles 1-3 form a gel from CHCl3-CH3OH (2 : 1, v/v) mixture solvents. In contrast, compounds 4 and 5, which are devoid of triazoles, are unable to form a gel under similar conditions and thus validate the essential role of triazoles in gelation. While the gel phase of 1 detects Cu2+ ions by showing phase transformation from gel to sol, gels derived from 2 and 3 undergo disintegration in the presence of Ag+, Cu2+ and Hg2+ ions. Such phase changes corroborate the visual sensing of metal ions. Moreover, the fluorescence titration of 3 discriminates Cu2+, Hg2+ and Ag+ ions by exhibiting differential quenching.