Regulation of the supramolecular self-assembly process by the number of 1, 8-naphthalimide groups in the gelator

Three naphthalimide-based gelators (NE1,NE2, NE3) with corresponding one, two and three N-undecanoic acid methylester-1,8-naphthalimide were designed and synthesized (the abbreviation NE1-NE3, N assigned to the naphthalimide, E assigned to ester, and numerber representing the number of N-undecanoic acid methylester-1,8-naphthalimide) The different number of 1, 8-naphthalimide groups in gelator endowed them with the different central groups, conjugated structures and steric configurations, which could bring different self-assembly abilities and behaivors. The self-assembly processes of three gelators in different solvents were characterized by multiple characterization technologies. The gelation ability, self-assembly structure, fluorescence emission behavior, material surface wettability of this system could be regulated by the number of 1, 8-naphthalimide groups. Gelator NE1 possessed the best gelation ability among three gelators, and the self-assembly structures in gels NE1 from different solvents were completely different from that of gels NE2 and NE3. In addition, surface wettability of film NE1 exhibited the highest hydrophobicity under the same condition. Fluorescence emission behavior of this system could be tuned by the number of 1, 8-naphthalimide groups solvent and gel state. At the same condition, the absorbance at the same band was gradually decreased with the number of 1, 8-naphthalimide groups increasing. This work will provide a new design way for construction of functional supramolecular self-assembly process.