基于4-氨基吡啶衍生物的有机凝胶及其离子响应

Organogels Based on 4-Aminopyridine Derivatives and Their Ion Response

以4-氨基吡啶为原料,合成了烷氧基侧链数目不同的凝胶因子——吡啶酰胺衍生物V1、V2和V3,测试了其凝胶能力和离子响应性质。SEM结果表明,V1、V2和V3所形成的凝胶是纤维状三维网络结构;XRD结果显示,V1、V2和V3均为层状结构。采用FTIR、UV和1HNMR考察了它们的成胶驱动力,结果表明,氢键、π-π作用和范德华力是形成凝胶的推动力。离子响应测试表明,该系列凝胶化合物能够分别对F^-和Cu^2+的刺激作出响应,通过在体系中加入F^-和F^-的质子化,或者使体系中的Cu^+氧化和Cu^2+还原、Cu^2+的释放和络合,可以实现凝胶一溶胶的多次可逆转变。该系列凝胶可以通过热、氧化还原反应或者添加适当的化学物质来调控体系的相变,是一类多重响应型有机小分子凝胶。

Picolinamides with one, two and three alkoxy chains, named Ⅴ1, Ⅴ2 and Ⅴ3, were synthesized. Their gelation properties and ionic response properties were tested. The scanning electron microscopy(SEM) results showed that three compounds could form fibrous gelation with ribbon like three-dimensional network structures. The X-ray diffraction(XRD) analysis revealed that all compounds were lamellar structures. Their gelation forces were characterized by Fourier transform infrared spectroscopy(FTIR), ultra-violet-visible spectroscopy(UV) and proton nuclear magnetic resonance(1 HNMR) spectroscopy. The results indicated that the driving forces of gelation were hydrogen bonding, π-π interaction, and van der Waals interaction. The organogels of compoundsⅤ1, Ⅴ2 and Ⅴ3 could exhibit stimuli responses to both F-and Cu2+. Their reversible gel-sol transitions could be induced by adding and removing F-, or reducing Cu2+and oxidizing Cu+, coordinating Cu2+ and releasing Cu2+, respectively. So, this series of organogels can regulate the phase transition of the system by heat, oxidation and reduction reaction or adding appropriate chemical substances and is a kind of multi-response organic small molecular gels.