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

摘要:

合成了烷氧基侧链数目不同的吡啶酰胺衍生物Ⅴ1、Ⅴ2和Ⅴ3，测试了它们的凝胶能力和离子响应性质。SEM观测结果表明Ⅴ1、Ⅴ2和Ⅴ3所形成的凝胶是纤维状的三维网络，XRD实验结果显示它们均为层状结构。采用FTIR、UV和1H NMR研究了这些化合物的成胶驱动力，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Cu2+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Cu2+还原、Cu2+的释放和络合，可以实现凝胶-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，是一类多重响应型的有机小分子凝胶。

Abstract:

Picolinamides with one, two and three alkoxy chain(s), named V1, V2, and V3, were synthesized and their gelation properties, together with the ion response of their organogels were tested. The microstructure and gelation force of the gels from the three compounds were checked by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultra-violet-visible spectroscopy (UV) and 1H nuclear magnetic resonance (1H NMR). Though the number of alkoxy chain of the three picolinamides is different, the morphologies of the checked organogels from them are all fibrous and they have clear ribbonlike 3D networks. What is more, they all have lamellar structure. It is found that hydrogen bonding, π-π interaction, and van der Waals interaction are the driving force of gelation. The organogels from V1, V2, and V3 can respond to the stimuli of both F-and Cu2+. Their reversible gel-sol transitions can be induced by heating and cooling, adding and removing F-, reducing Cu2+ and oxidizing Cu+, coordinating Cu2+ and releasing Cu2+, respectively. The organogels are efficient multiple responding ones.