Porphyrinic covalent organic framework designed by molecular engineering as heterogeneous photocatalyst for aerobic mediated RAFT polymerization

Abstract

Covalent organic frameworks (COFs) have gained increasing attention as heterogeneous materials for their prominent applications in photocatalytic processes. The already tailored structure endows COFs with ordered dimensional channels for the separation and migration of the electro-hole pairs and improves their photocatalytic properties. In this contribution, oxygen-mediated RAFT polymerization was achieved by using M-TCPP-DHTA-COFs (M = H2 or Zn) as photocatalysts with the assistance of TEA as co-catalyst producing polymers with accurate molecular weight and narrow molecular weight distribution under visible light irradiation. The control experiments revealed excellent dual control behavior of light and gas toward polymerization processes. Notably, porphyrinic COFs can be straightforwardly separated and recycled for recycling experiments and exhibit remarkable compatibility features of controllable polymerization for functional monomers under aerobic conditions. This study offers a promising pathway for the construction of an efficient heterogeneous catalyst of oxygen-mediated RAFT polymerization and extends the novel applications of porphyrin-based COF materials.