Bis-naphthalimides self-assembly organogel formation and application in detection of p-phenylenediamine

Two new gelators containing bis-naphthalimides group were designed and synthesized. The gelator 1b could form gels in DMF and mixed solvent of DMSO/H₂O (10/1, v/v). The self-assembly processes of 1b in two kinds of solvents were detailedly investigated by UV-vis, fluorescence, infrared spectroscopy, field emission scanning electron microscope (FE-SEM), X-ray diffraction and contact angle experiments. The experiment results showed the hydrogen bonding was the main force for the gel formation. The gel 1b formed in mixed solvent of DMSO/H₂O (10/1, v/v) possessed of the ability of distinguishing of o-phenylenediamine, m-phenylenediamine and p-phenylenediamine. At the same time, the gelator 1b could selectively and sensitively detect p-phenylenediamine in solution with the detection limit of 8.961×10^-8ML^-1. The detection experiment was also confirmed by DFT theoretical calculations. This research would expand the supramolecular self-assembly materials application in sensor field and offer a new detection method for organic amines.