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

Abstract

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.