Synthesis And Properties Of Low Molecular Organic Gelators Based On Pyridines And Coumarins

Nowadays, low-molecular-weight gelators have attracted considerable attentions in thesupremolecular chemistry, because of its facile preparation, mild condition and controllablemicrostructure. Generally speaking, the organogelators could be self-assembled into variousdimensional morphologic superstructures in the organic solvents though noncovalentinteractions such as H-bonding, π-π stacking, van der Walls force, electrostatic interaction ect.Meanwhile, the organogelator could be selectively functionalized with the introduction ofdesired moieties so as to build up target system with intriguing optical, electrical andmagnetical properties that would facilitate its wide application in the industry.A series of pyridines(A1-A3, B1-B3) and coumarins(C1-C3) compounds as lowmolecular mass organogelators (LMOGs) were designed and synthesized based on ethyl3,4,5-tris(hexadecyloxy)benzoate. The synthesized compounds were characterized by1HNMR,13C NMR, FTIR spectrum, MS and elemental analysis. Two component gelatorscomposed by Pyridine compounds as proton acceptor and the carboxyl group-containingcoumarin-3-carboxylic acid, glutaric acid, tartaric acid as the proton donor. The gelationability was tested in various solvents such as esters, amines, aliphatic hydrocarbons, aromatichydrocarbons, alcohols, organic acids, etc.A1-A3, B1-B2and C1exhibits excellent gel properties, A1-A3, B1-B2and twocomponent gelators gel properties vary. To futher understand the morphologies of the gels,SEM skill was adopted. It was investigated not only the solvents, but also the substituents andtwo component gelators could affect the microstructure of the gels. Pyridines organogels werethe pH response. Complex which composed of A1-A3, B2-B3and Ag+could self-assembleinto organogels in benzene and substituted benzene. The organogel based on theAg-coordinated complex shows a quick response to Cl–, Br–, I–, H+and OH–. Fluorescencedifferences of A1-A3were studied between the liquid and gel states, fluorescence of liquidA1-A3was varied by mixing metal ions. Two component gelators were characterized byFTIR spectrum.