Abstract

In this work, we report a series of crystalline viologen-based porous ionic polymers (denoted VIP-X, X = Cl or Br), that have in situ formed dicationic viologens paired with halogen anions and intrinsic hydrogen-bonded water molecules, towards metal-free heterogeneous catalytic conversion of carbon dioxide (CO2) under mild conditions. The targeted VIP-X materials were facilely constructed via the Menshutkin reaction of 4,4′-bipyridine with 4,4′-bis(bromomethyl)biphenyl (BCBMP) or 4,4′-bis(chloromethyl)biphenyl (BBMBP) monomers. Their crystalline and porous structures, morphological features and chemical structures and compositions were fully characterized by various advanced techniques. The optimal catalyst VIP-Br afforded a high yield of 99% in the synthesis of cyclic carbonate by CO2 cycloaddition with epichlorohydrin under atmospheric pressure (1 bar) and a low temperature (40 °C), while other various epoxides could be also converted into cyclic carbonates under mild conditions. Moreover, the catalyst VIP-Br could be separated easily and reused with good stability. The remarkable catalytic performance could be attributed to the synergistic effect of the enriched Br− anions and available hydrogen bond donors –OH groups coming from H-bonded water molecules.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.