Polycatenane, the Approach and the Perspective to the Novel Polymerization

摘要

Catenane is an interlocked compound that is composed of only cyclic components. Since the directed synthesis of the interlocked compound was proposed by Sauvage at 1983 using metal-coordination, catenanes with various structures have been synthesized by utilizing various intermoiecular interactions. Polycatenane is a polymer in which the cyclic components are interlocked to each other to form polymeric chain. The unique character has been expected for the polycatenane because of its unique structure. Many chemists have extensively studied the preparation of polycatenane although all attempts were unsuccessful. The conventional approach to the polycatenane has been the catenative cyclization-polymerization of tetravalent catenane precursor (Figure 1). However, this approach has the theoretical problem that the cyclization is incompatible with the polymerization. Therefore, the product always includes the linear polymer or the large macrocycle.