Supramolecular polymers based introduction

With the introduction of supramolecular polymers, which are polymers based on monomeric units held together with directional and reversible secondary interactions, the playground for polymer scientists has broadened and is not restricted to macromolecular species, in which the repetition of monomeric units is mainly governed by covalent bonding. The importance of supramolecular interactions within polymer science is beyond discussion and dates back to the first synthesis of synthetic polymers the... 

This section discusses the scope of [60]fullerene-based polymer chemistry. These approaches may allow for the development, on a supramolecular level, of unprecedented architectures. Previous sections have dealt primarily with the self-assembly of the [60]fullerene and its derivatives as a result of microphase separation and subsequent formahon of huge [60]fullerene clusters driven by the weak noncovalent forces in the solid state, mesophase and water. To avoid microphase separation, the introduction of functionalized [60]fullerene derivatives into polymer main chains through noncovalent interactions is a very promising approach. The construction of fullerene-containing supramolecular polymers in organic solution is now presented. 

Another case of a supramolecular cyclic structure is illustrated in the formation of the four-component porphyrin cage 13 (Fig. 9) [42]. In the absence of triaminopyrimidine, the uracil moieties appended to the porphyrin exist as a mixture of syn- and antz-atropisomers. Upon introduction of triaminopyrimidine, the presence of the anti isomer decreases to less than 20%, suggesting formation of 13. The presence of 13 is further supported by electrospray mass spectroscopy and vapor pressure osmometry analyses. Similarly, rigid scaffolds bearing complementary DNA bases form closed ensembles, rather than linear polymers, as evidenced by the solution-state dimerization of 14 (Fig. 10) [43]. 

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