Water-Assisted Formation of Supramolecular Self-Assembly Systems Based on Distyrylbenzene Derivative

Two new pi-conjugated distyrylbenzene derivatives (1O and 1S) were synthesized and carefully characterized through the reaction between 2-furaldehyde or 2-thiophenecarboxaldehyde and p-phenylenediacetonitrile. Organogels 1O and 1S could be obtained in some mixed solvents through addition of water and further balance the solubility. Compounds 1O and 1S had different self-assembly behavior even if only the difference of one atom in their molecular structures. Organogels 1O and 1S could emit yellow light with the large red-shift comparing with that of solution state. The emission properties of compounds 1O and 1S in single molecule and dimmer mode were further verified through theoretical calculation. From the UV-vis absorption spectra, fluorescence emission spectra, FTIR and XRD experiments results, pi-pi stacking interaction and strong intermolecular secondary bonding interaction were the main driving force for organogel formation. The different structure from willow leaf-shaped structure constructed by micron piece to micron fibers structure could be observed through the self-assembly of molecules 1O and 1S in mixed solvents which exhibited different degrees of hydrophobicity with contact angles of 92 degrees-135 degrees. This self-assembly behavior could be tuned via different atom in terminal group of gelator molecule structure. This research would provide a new sample for designing functional pi-conjugated supramolecular self-assembly system.