Pseudopolyrotaxanes synthesis

It was in 1976 that Ogata et al. reported the synthesis of inclusion polyamides [78]. When /1-cyclodextrin was stirred with aliphatic diamines in water, precipitates were formed and they were characterized as inclusion compounds. Condensation of these inclusion amides with isophthaloyl or terephthaloyl chloride yielded polyamides encircled by many of the cy-clodextrins, i.e., the first pseudopolyrotaxanes. Ogata et al. likened them to a train passing through many tunnels . The solubility and water absorption of the pseudorotaxanes were greater than those of the naked polymer threads. Differential thermal analysis experiments showed that the thermal properties of the pseudorotaxanes were different both from the naked threads and from /1-cyclodextrin. 

Figure29 The metal-templated synthesis of the pseudorotaxane 107 and its two-step conversion into the ladder pseudopolyrotaxane 109.

Harada et al. [18] reported the synthesis of a [2]rotaxane capped by j6-CD and a trinitrophenyl group. The /i-CD at the end binds the trinitrophenyl group stopper of another [2]rotaxanes gives a rotaxane aggregate, as shown in Fig. 2. Liu et al. [19] also developed a simple strategy to prepare polyrotaxane-like supramolecules. An inclusion compound had been synthesized by the complexation of 4,4 -di-pyridine and j6-CD in water the subsequent coordination of the complex with nickel ions in aqueous solution gave the corresponding pseudopolyrotaxane. 

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