2017 Volume 38 Issue 2 Pages 86-92
In this report, the formation of supramolecular gels from an amphiphilic calix[4]resorcinarene(CR) and proline was investigated. CR with four alkyl chains of ten carbon atoms (CR(10)) was prepared by the condensation of resorcinol and undecanal under acidic condition in high yield. CR(10) forms microphase separation structures. Therefore, CR(10) exhibits a strong aggregation capability. CR(10) formed l:l host-guest complex with proline and assembled into nanofibers in methanol. As a result, the nanofibers were entangled with each other and formed the supramolecular gels (CR-Pro gels). It was found that the supramolecular gels obtained from CR(10) and racemic proline showed higher sol－gel transition temperature than those of the supramolecular gels obtained from CR(10) and D- or L-proline, respectively. From the result, the formation of supramolecular gel is supposed to be driven by two kinds of interactions. One is the hydrogen bonds between CR(10) and proline and the other is the intermolecular interaction between proline molecules. It seemed that the sol－gel transition temperature of CR-Pro gels strongly depended on the interaction between proline molecules.
