杯[4]芳烃羧酸衍生物的合成及其胶凝行为

作为第三代主体化合物,杯芳烃及其衍生物具有重要的研究价值和应用前景。 本工作分别合成了对叔丁基杯4]芳烃单羧酸、二羧酸和四羧酸3种衍生物(CMA、CDA和CTA)。 与预期一致,这种本体疏水、上缘携带疏水结构、下缘携带亲水基团的杯4]芳烃衍生物虽然具有典型的两亲性化合物结构特征,但却与一般表面活性剂不同,很难溶于水。 胶凝实验发现,CDA和CTA分别可以胶凝17种有机溶剂和10种可聚合单体中的1种和7种,CMA和未修饰的对比物C4不含羧酸结构单元,不能胶凝其中任何一种。 其中,CTA的可聚合单体凝胶不但具有良好的热可逆性,而且在水存在下,可以形成稳定的凝胶乳液。 以此凝胶乳液为模板,通过聚合得到了具有不同微观结构的多孔块材。 初步的吸附实验发现,这类材料对水体Cr(Ⅲ)、苯等污染物具有一定的脱除能力并可通过简单洗脱和干燥再生,有望在净水方面获得应用。

Preparation and Gelation Behaviors of New Carboxyl Acid-appended Calix[4]arene Derivatives

Calixarenes, as the third generation of host molecules in supramolecular chemistry due to their facile modification and unique molecular or ion recognition ability, have received great attention during the last few decades. In the present work, three carboxyl acid-appended calix4]arene derivatives were prepared. The compounds are characterized by four tert-butyl groups appended at the upper rim of the main body of the compounds, and one, two or four carboxyl acid moieties appended at the lower rim, of which they are denoted as CMA, CDA and CTA, respectively. The as-prepared compounds possess surfactant-like structure but insoluble in water. Gelation tests reveal that the compound with more carboxyl groups shows stronger gelation ability. For example, among the seventeen organic liquids and ten monomeric liquids tested, CTA gels seven of them, CDA gels one of then, but CMA and the control C4, which possesses none of the carboxyl acid structure, gel none of them. Further studies demonstrate that the CTA gels with monomeric liquids as solvents have good heat reversibility and can be emulsified with water, resulting in gel-emulsions. Polymerization of the gel-emulsions results in low density polymeric monoliths with porous internal structures. Preliminary test shows that the porous materials as produced are good adsorbents of organic liquids such as benzene, and heavy metal ions such as Cr(Ⅲ). Moreover, the materials can be reused via simple washing and drying process and have potential application in water purification.