Calix[5]arene-based Supramolecular Polymers

Research on supramolecular polymers is in full bloom: the seed was planted 25 years ago, with the first report on the hydrogen bond-directed self-assembly of liquid crystalline polymers, and it has now branched out in several directions, each characterized by different recognition motifs and non-covalent interactions underlying the most diverse families of supramolecular polymers devised so far. Among these, calixarene-based polymers have been intensively studied, even though calix[5]arenes have enjoyed much less attention than the smaller homologous calix[4]arenes. Three strategies have emerged so far for the construction of AABB- and/or AB-type polymers, namely, C-60 encapsulation, primary alkylammonium complexation, and organic cations recognition. This review article aims at organizing the results obtained (and knowledge gained) to date on the self-assembly of calix[5]arene-derived building blocks.