Synthesis And Gelation Behaviour Of The Naphthyl-based Di-hydrazide Derivatives And Co-assembly Of Two-component Composing Of Di-hydrazide Derivatives

We have designed and synthesized two kinds of naphthyl-based di-hydrazidederivatives (NHT6,2NHT6).We studied the gelation properties and the influence ofnaphthalene’s different substitute position on gel behavior. The co-assembly behaviorof the two-component complex based on di-hydrazide derivatives has been studied.The effect of the complexing ratios on the co-assembly process, gelation potentialand morphologies was investigated and the co-assembly model was given. The mainconclusions are as follows:1. Temperature-dependent and concentration-dependent1H NMR spectroscopic andIR absorption spectroscopy was used to study the self-assembly of NHT6and2NHT6,the results showed molecules organized to form supramolecules throughself-complementary quadruple hydrogen-bonding. They both form stable gel inethanol and1,2-chloroethane (the critical gel concentration <5mg/mL).2NHT6isinsoluble in most common organic solvents. However, NHT6form a organogel inbenzene, toluene, tetrahydrofuran, chloroform and acetone, etc. The gel showsperfect stability performance, its Tg is as high as90℃in ethanol. Xerogels ofNHT6and2NHT6from ethanol consist of strip fibers with the width of100nm.2NHT6exhibits liquid crystal state in the cooling process, hexagonal columnar phasewas confirmed showing needle-like texture at210℃.2. The effect of central unit on the gelation of wedge di-hydrazide derivatives wasinvestigated. The derivatives are TC6(1,4-phenylene), NHT6(1,4-naphthalene) and2NHT6(2,6-naphthalene)respectively, depending on the central unit. The resultsshowed NHT6can gel a variety of organic solvents with preferably thermal stability. While2NHT6shows liquid crystal behavior.3. We have studied the co-assembly behavior in chloroform of two-componentcomplexes composing of BPH8and TC6. Solubility, gelation process, aggregationmorphology and thus molecular arrangement of the complexes changed with theration of BPH8and TC6. The gel stability, gelation time and aggregation-inducedemission (AIE) intensity decreased with the increase of TC6. The xerogel of BPH8/TC6blend exhibited fiber or network. BPH8shows a very poor solubility, TC6’ssolubility is quite excellent. As TC6proportion increased in blend, the stability of thegels decreased and it took longer time for gelling, and meanwhile the aggregatesmorphology changed from fiber to sheet.1H-NMR, UV absorption spectroscopicresults showed the no configuration change was observed in the mixtures whichdoes exist in the pure BPH8/CHCl3system, suggesting that intermolecular interactionbetween BPH8and TC6. New aggregates formed in the mixtures.1H-NMR showsthat two-component, TC6and BPH8co-assemble in the supramolecules throughhydrogen-bonding at the molecular level.With the addition of TC6, the BPH8’ssolubility increased from0.002mg/mL to1.08mg/mL. While in the gel network ofthe mixture, the molecular ratio of BPH8and TC6is6:1.