Designed synthesis of Co salen‐based metalated crystalline polymers.

In this contribution, we for the first time propose the targeted synthesis of Co‐metalated salen‐based crystalline polymer, starting from corner and square building units in the presence of cobalt metal ions. On the basis of structural characterizations, this kind of salen‐based crystalline polymer is proved to be the long hollow tube. Due to its covalent connected unique structure, the obtained Co‐salen polymer possesses high crystallinity and excellent stability. The experimental and theoretical studies show that this kind of material holds paramagnetism, unique electronic structure, and remarkable catalytic activity with high selectivity for the coupling of CO2 and epoxides to form cyclic carbonates. And specifically, it shows favorable recyclability with only a slight drop in yield after six catalytic cycles. We hope that the results reported here will greatly inspire the design and synthesis of different metalated salen‐based polymer and enlarge their interesting applications in the future. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 641–647 This article introduces the synthesis of Co salen‐based crystalline polymers; most of the atoms in this polymer are linked by covalent bonds. The formation mechanism of this polymer is displayed. The SEM and TEM characterizations match well with the formation mechanism, confirming that this polymer is self‐assembled by more little nanotubes. Due to the covalent connection and the introduction of Co species, this polymer has high crystallinity according to powder X‐ray diffraction analysis. [ABSTRACT FROM AUTHOR]