Amide-based poly catenanes

Physical properties of these poly[2] catenaries have been explored in expectation of unique properties based on the catenane structure [239, 246]. While various interesting physical properties were found in polyrotaxane, no characteristic property has been reported in [2]catenanes so far. Although poly[2]catenane has highly mobile moiety due to the mechanical bond, it has been suggested that the connection between [2]catenane subunit restricted the mobility in motion of [2]catenane. Further, intramolecular interaction in [2]catenane subunit may decrease its mobility. Secondary amide-based [2]catenanes can easily be prepared from commercially available compounds. Takata et al. found that the borane-reduction of the [2]catenanes afforded good yields of the amine-based [2]catenanes that can be useful for polymer synthesis [247, 148] (Scheme 51). Although the origi-... 

Scheme 17.5 Synthesis of amide-based poly[2]catenanes 12a and 12b. BnO, benzyloxy group.

Takata et al. reported another very interesting amide-based poly[2]catenane (or oligo[2]catenane) 19 (Scheme 17.8) [57]. Here, the [2]catenane monomer 18 was synthesized in a high yield by utilizing macrocycle-1 as a template (this has proven to be a good templating precursor for the synthesis of catenanes) [56, 82]. Poly[2]catenane 19 was prepared via the Diels-Alder polymerization of 18 at 140°C, without solvent, for several hours. According to GPC analysis with... 

Scheme 17.7 Synthesis of amide-based poly[2]catenane 17. DCC, N,N -dicyclohexylcarbodiimide.

Gibson and coworkers reported the details of poly(amide-crown ether)-based polypseudorotaxanes, which were suggested to have catenane structures (Scheme 17.25) [154, 155]. In these studies, poly(amide-crown ether)s... 

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