Porphyrin–based Vinylene–linked 3D Covalent Organic Framework with Unprecedented cya Topology for Photocatalytic H2O2 Production

Designing and realizing new topologies represent one of the most important ways toward developing new structures and functionalities for molecule–based frameworks including SOFs, MOFs, and COFs. Herein, Aldol condensation between 5,10,15,20–tetrayl(tetrakis(([1,1':3',1''–terphenyl]–4,4''–dicarbaldehyde)))–porphyrin (TTEP) and 2,4,6–trimethyl–1,3,5–triazine (TMT) affords the vinylene–linked 3D covalent organic framework Por–COF–cya. Powder X–ray diffraction (PXRD) in combination with structural simulation reveals its high crystalline structure with an unprecedented cya topology in the molecule–based frameworks reported thus far. Por–COF–cya displayed polycrystallinity and possessed high permanent porosity. Especially, the incorporation of light–harvesting porphyrin unit and vinylene linkages in Por–COF–cya enables a conjugation effect within the framework, endowing it with a photocatalytic H2O2 production rate of 2209 μmol g−1h−1 in pure aqueous solution under visible–light irradiation (λ > 400 nm). Inclusion of the guest molecules TTF into the pores of Por–COF–cya results in a donor–acceptor system TTF@Por–COF–cya, enhancing the photocatalytic activity with H2O2 production rate of 6994 μmol g−1h−1. This work paves a new way for the development of new topological functional molecule–based frameworks toward diverse application potentials.