Gallic-Acid-Modified Naphthalimide Containing Disulfide Bond as Reduction-Responsive Supramolecular Organogelator

The development of low molecular-weight gelators for the construction of stimuli-responsive gels is increasing attention because of the great application potential. In this work, we report the design and synthesis of two new naphthalimide derivatives, GSSN and GN, as supramolecular organogelators. GSSN contains a disulfide bond in the molecule, while GN contains no disulfide bond. As a result, only GSSN exhibited reduction responsiveness. A series of tests, including UV-vis, temperature-dependent H-1 NMR, XRD, and SEM, were carried out to characterize the gelation capability and probe into the gelation mechanism. Results showed that GN can gelate more organic solvents than GSSN. Both hydrogen bonding and pi stacking contribute to the gelation. Due to the difference in the assembly of the organogelator molecules, the organogels formed by GSSN and GN presented distinct morphologies. Moreover, strong hydrophobicity was found in the organogel films of GSSN and GN, suggesting potential application as hydrophobic coating materials.