超分子聚合物(supramolecular polymer)是指单体单元间依靠可逆和高度取向的非共价作用力结合的、在溶液或本体中表现出聚合物特性的一类特殊聚合物.其中,氢键结合超分子聚合物因氢键的高度取向性及丰富的结合形式而具有特殊结构与性能,已成为近期关注的热点心.文献中报道的氢键结合超分子聚合物主要有多重氢键结合和基于羧基与吡啶基的氢键结合(其键能可达45kJ·mol^1[5])两类,它们均可表现出和传统聚合物诸多类似的性质,诸如高的溶液粘度、形成凝胶、具有弹性等,同时其结构和性能又随温度等环境条件的变化而发生可逆变化,使得这类超分子聚合物有很多潜在的应用.基于多重氢键之间的相互叠加作用可形成多种超分子聚合物,如Meijer等报道了四重氢键结合的脲酰嘧啶酮(ureidopyrimidinone)超分子体系,其单体单元的合成较复杂.而基于羧基与吡啶基形成的超分子聚合物,官能团通常处于不同的单体单元中,这一体系与基于多重氢键的体系相比更加易于制备.
A new kind of supramolecular building unit (defined as SBU) having two phenolic hydroxyl groups (proton donors) and two aromatic carboxyl groups (proton acceptors) was synthesized from 1,2,4, 5-benzene tetracarboxylic acid and 4-hydroxy pyridine by a simple procedure. Based on ^1 H-NMR, IR, EA and XRD analyses, the structure of SBU was defined. Under suitable conditions, supramolecular gels and fibers were formed from the building unit through multiple hydrogen bonds between the donors and the acceptors. These supramolecular structures demonstrated strong temperature dependant features.