水诱导N,N′,N″-三(4-吡啶基)-均三苯甲酰胺形成超分子凝胶研究  

Supramolecular Gels Formation from N,N',N''-Tris(4-pyridyl)trimesic Amide Induced by Water

作　　者：罗海清 刘启昊 朱万财 王科军[1] 罗序中 

机构地区：[1]赣南师范学院化学化工学院,赣州341000

出　　处：《化学学报》2015年第10期1031-1037,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(No.51268002);江西省自然科学基金(Nos.20142BCB22007;20143ACB20009);江西省教育厅项目(No.KJLD14080);江西省"赣鄱英才555工程"资助~~

摘　　要：以均三苯甲酸为母体分子,用4-氨基吡啶对其进行化学修饰,合成了N,N′,N″-三(4-吡啶基)-均三苯甲酰胺(4-btapa)并考察其在不同溶剂及酸碱度中的胶凝性能.实验结果表明,4-btapa不溶于水,但可溶于一些极性溶剂中.室温条件下,在4-btapa的DMSO溶液中加入适量的水,可直接形成稳定凝胶.而在DMF,THF等溶剂形成的溶液中室温条件下加入适量的水得到只能得到粘度较大具有流动性的混浊液,但将得到的混浊液加热溶解后室温冷却均能形成稳定凝胶.扫描电子显微镜观察到4-btapa在不同含水有机溶剂中都能形成纤维状自组装聚集体,而4-btapa在p H=3.0的水-乙醇体系中呈明显的纤维团簇结构,与p H=7.0时的规则的纤维结构相比存在较大的差异,说明p H值会影响凝胶因子聚集形貌.核磁共振和红外光谱结果表明凝胶中存在N—H…Py的分子间氢键和芳香环的π-π堆积作用.根据FT-IR,1H NMR结果并比对干凝胶与晶体XRD曲线得到了凝胶因子4-btapa在凝胶(p H=7.0)中的自组装排列方式.N,N＇,N＂-Tris（4-pyridyl）trimesic amide （4-btapa） was synthesized by chemical modification using 4-aminopyridine to benezene-1,3,5-tricarboxylic acid. The gelating ability of 4-btapa to different solvents and the effect of pH on gelating ability were studied in detail. The results indicated that a stable gel was obtained by adding a certain amount of water to a 4-btapa DMSO solution at room temperature. While adding a certain amount of water to solutions of 4-btapa in DMF, THF, methanol and so on, respectively, only flow turbid liquids with large viscosity were obtained. Upon heating the obtained turbid liquids to clear solutions and cooling them at room temperature, stable gels were also obtained. The structures of the aggregates in the gels were investigated using Fourier-transform infrared spectroscopy （FT-IR）, nuclear magnetic resonance （NMR） spectroscopy, small angle X-ray scattering （SAXS） and scanning electron microscopy （SEM）. The result of SEM shows that the 4-btapa can form fibrous self-assembly aggregates in different aqueous solvent, while 4-btapa shows the fiber cluster structure at pH=3.0 water-ethanol system, which is different from regular fibrous aggregate in pH=7.0, suggesting that the pH can affect the aggregation morphology of gelators. The results of nuclear magnetic resonance and infrared spectroscopy revealed that the molecular hydrogen bonds of N--H…Py and aromatic π-π stacking interactions were formed in gel state and water was a part of the gel. From the above observation and analysis of FT-IR, ^1H-NMR and XRD results, we can suggest the self-assembly arrangement of 4-btapa in gel state.

关 键 词：水诱导 超分子凝胶 N N′ N″-三(4-吡啶基)-均三苯甲酰胺 自组装 

分 类 号：O648.17[理学—物理化学]