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The purification step in the manufacturing of cyclic polymers is difficult as complete fractionation to eliminate linear impurities requires considerable effort. Here, we report a new polymer separation methodology that uses metal‐organic frameworks (MOFs) to discriminate between linear and cyclic polyethylene glycols (PEGs) via selective polymer insertion into the MOF nanopores. Preparation of a MOF‐packed column allowed analytical and preparative chromatographic separation of these topologically distinct pairs. In addition, gram‐scale PEGs with only cyclic structures were successfully obtained from a crude reaction mixture by using MOF as an adsorbent. [ABSTRACT FROM AUTHOR]

Cyclic polymers, possessing no chain ends, exhibit chemical and physical properties that can be distinguished from the linear counterparts. The synthesis of cyclic polymers has been pursued, and their functionalities arising from the unique shapes, namely topology effects, have been investigated. The ESA-CF process in conjunction with click chemistry selectively constructed a variety of unprecedented multicyclic topologies of polymers such as bridged- and spiro-types. It was demonstrated that cooperative electrostatic and hydrogen-bonding self-assembly followed by covalent conversion is an effective means for the synthesis of polymeric catenanes. The self-assembly of a cyclic amphiphilic block copolymer, prepared by intramolecular metathesis, gave a micelle with an approximately 50°C increase in the thermal stability in comparison with one formed from the linear precursor. Furthermore, linear and cyclic polymers containing a perylene diimide unit were synthesized, and single-molecule spectroscopy revealed the different diffusion modes of the polymers on the basis of their topology. [ABSTRACT FROM AUTHOR]