Sonication-Induced, Solvent-Selective Gelation of a 1,8-Napthalimide-Conjugated Amide: Structural Insights and Pollutant Removal Applications

Reported herein is the synthesis, characterization, and dye removal applications of a highly solvent-selective organogel-forming amide, compound 1, which contains a 1,8-naphthalmide moiety, flexible n-hexyl chain, and benzene ring. This compound displayed remarkable solvent selectivity, with gel formation occurring only in the presence of alkylated aromatic solvents. Detailed structural characterization of the gels, combined with notable theoretical insights, is invoked to explain the highly selective gelation properties of compound 1, as is a comparison to non-gel forming structural isomer 2, which contains the same structural elements in a different arrangement. Finally, the ability of the gel derived from compound 1 to act as a reusable material for the efficient removal of cationic organic dyes from contaminated aqueous environments is also reported, with up to 11 repeated uses of the gel still maintaining the ability to effectively remove Rhodamine B.