Polycatenanes polymeric catenanes

The interest in macromolecular systems containing defined topological bonds, such as polyrotaxanes 7, multicatenanes 8, polycatenanes 9, poly[2]catenanes 10, and polymeric catenanes 11, is dual. First, these macromolecules represent daunting synthetic and characterization challenges which deserve attention in their own... 

Scheme 29. Unreported macromolecular architectures containing defined topological bonds polycatenane 9, linear poly[3]catenane 74, poly[2]catenane network 75, multicatenane network 76, rigid polymeric catenane 77, polymeric trefoil knot 78, and polyknot 79.

Greets Y (1999) Polycatenanes, poly[ 2]-catenanes and polymeric catenanes. In Sauvage JP, Dietrich-Buchecker CO (eds) Molecular Catenanes, Rotaxanes, and Knots. Wiley-VCH, Weinheim... 

Over the past few decades, much attention has been focused on polycatenanes, which consist of mechanically interlocked structures that have novel topologies and, not unexpectedly, display somewhat different properties than do commonly used, conventional polymers. The linear polycatenanes (type A in Figure 17.1) are aesthetically perfect, and are expected to possess maximized effects of topologically bonded structures on properties. However, the synthesis of such linear polycatenanes remains one of the most difficult and as-yet unachieved synthetic goals in polymer science. Due to the relatively easy preparation of bifunctionaUzed [2]catenanes, success in the directed synthesis of polycatenanes has been mainly limited to the poly[2]catenanes, which contain essential mechanical hnkages. Nonetheless, some progress has been made recently towards creating polymeric catenanes and polycatenane networks. 

Catenanes are not limited to species involving two macrocycles and several examples of oligomeric and polymeric complexes are known. Polymeric catenanes are termed [n]-polycatenanes, whereby n is the number of rings in the chain although there is no clear point at which the term [n]-catenane ends and [n]-polycatenane begins (Figure 3.33(a)). A variation on polycatenanes are... 

BerrocalJA, Pitet LM, Nieuwenhuizen MML, Mandolini L, MeijerEW, Di Stefano S. Ring-opening metathesis polymerization of a diolefmic [2]-catenane-copper(I) complex an easy route to polycatenanes. Macromolecules. 2015 48 1358-1363. 

Poly[2]catenane occupies an important position of the topologically linked polycatenanes that incorporate the [2]cate-nane linkages in the main chain. Its preparation usually requires the polymerization of two reactive-sites-containing [2]catenane or ditopic [2]catenane. For this purpose, various... 

Many researchers have tried to prepare polycatenane. However, all attempts made so far have been unsuccessful. The first proposal for the preparation of poly[n]catenane was illustrated in the early 1970s. Most recent approaches for the synthesis of polycatenane have been carried out according to the typically efficient catenane synthesis that is used at the polymerization step based on the metal-templated catenation, which was first reported by Sauvage. However, polymerization always requires complete reaction efficiency nnlike simple organic reaction, and thereby the past approaches for the synthesis of polycatenanes encountered difficulties in terms of cycliza-tion efficiency, essentially requiring two-point connection (Scheme 13). ... 

When the polymerization of DT was performed in the presence of tydic poly(oxyethylene) (CPO), the product included a catenane stracture of cyclic poly(DT) and CPO entangled with each other. It was concluded that the poly(DT) obtained from polymerization of DT includes a polycatenane structure. ... 

Catenanes are two interlocked cycles, like two links in a chain, which cannot be separated without the breaking of a covalent bond. Rotaxanes are similar but are composed of a cycle encircling an acydic molecule like a ring around a thread. A naturally occurring rotaxane, DNA polymerase III encircles DNA dining replication. Polyrotaxanes and polycatenanes are well-defined repetitions of these interlocking stmctures and should not be confused with intertwined cross-linked polymers whose interconnectivity is random in nature. These intricate polymeric networks have posed challenges to synthetic chemists, and a few have utilized ROMP in their preparation. 

Macromolecules incorporating repeating units connected by covalent bonds are widespread in nature [1], Synthetic procedures for the construction of their artificial counterparts are well established [2], Furthermore, the properties of these unnatural macromolecules are now rather well understood and, indeed, polymeric materials have found applications in numerous branches of science and technology [2], In recent years, synthetic chemists have learned how to introduce mechanical bonds (Fig. 1) into small molecules. Mechanically interlocked rings, as well as wheels mechanically trapped onto axles, can be constructed efficiently to afford molecular compounds, named catenanes and rotaxanes, respectively.t Metal coordination [18-32], donor/acceptor interactions [33-43], hydrogen bonds [44-64] and/or hydrophobic interactions [65-78] between appropriate components have all been employed to template the formation of these exotic molecules. Making the transition from simple catenanes and rotaxanes to their macromolecular counterparts—namely, polycatenanes and polyrotaxanes. 

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