HIGHLIGHT Topological Polymer Chemistry by Electrostatic Self-Assembly

ABSTRACT: Recent developments in topological polymer chemistry are outlined. First, nonlinear polymer topologies are systematically classified on the basis of topological considerations of constitutional isomerism in a series of alkanes (C n H 2nϩ2 ), monocycloalkanes (C n H 2n ), and polycycloalkanes (C n H 2nϪ2 , C n H 2nϪ4 , etc.). Various pairs of topological isomers are identified in randomly coiled, flexible polymer molecules with cyclic and branched structures. An electrostatic self-assembly and covalent fixation strategy has subsequently been developed for the efficient synthesis of a variety of topologically unique polymers, including monocyclic and polycyclic polymers, topological isomers, and topological block copolymers. In this process, new telechelics with moderately strained cyclic onium salt groups carrying multifunctional carboxylate counteranions have been designed as key polymeric precursors. Further extensions of topological polymer chemistry have been achieved by the use of cyclic telechelics (kyklo-telechelics) and cyclic macromonomers, obtainable also by means of the electrostatic self-assembly and covalent fixation process