Diaminomalenonitrile-decorated cholesterol-based supramolecular gelator: aggregation, multiple analyte (hydrazine, Hg2+ and Cu2+) detection and dye adsorption

Abstract

A low molecular weight gelator (LMWG) containing a diaminomalenonitrile functional group 1 has been designed and synthesized. The compound forms supramolecular gels from DMF–H₂O and 1,2-dichlorobenzene. The morphology of the gels reveals fibrous networks. The rheological study demonstrates that the DMF–H₂O gel is stable and robust than the gel obtained from 1,2-dichlorobenzene, which is due to the existence of strong intermolecular forces among the gelators in DMF–H₂O. The analysis of tan δ values from the frequency sweep (tan δ = G′′_av/G′_av) indicates that the DMF–H₂O gel exhibits higher mechanical strength (lower tan δ) than the 1,2-dichlorobenzene gel. The DMF–H₂O gel has been explored for sensing and dye adsorption. The gel is established to be selective for visual recognition of hydrazine, Hg²⁺ and Cu²⁺ ions. Moreover, the gel exhibits excellent efficacy towards rapid and selective adsorption of cationic dyes from water (<1 min).