Ring-closing Polymerization (Cyclopolymerization) through Large Ring Formation

Abstract

Ring-closing polymerization (cyclopolymerization) is a very useful synthetic method for preparation of polymers possessing cyclic structures. These polymers containing cyclic structures are applied for high strength materials, and so on due to their good rigidity and high density. In addition, these polymers are applicable as molecular sensors, scavengers, stationary phases for chromatography, and so on by their specific interactions with ions and molecules. Ring-closing polymerization through 5- or 6-membered ring formation proceeds smoothly owing to the thermodynamic stability of the ring structures. In contrast, that with large ring formation requires precise molecular design of corresponding monomers. The resulting large ring structures potentially exhibit excellent and unique molecular recognition abilities. Herein, we review recent studies on ring-closing polymerization through large ring formation and applications of polymers bearing large the cyclic structures obtained by these polymerizations.