Donor-acceptor type[4+3]covalent organic frameworks:sub-stoichiometric synthesis and photocatalytic application

Three unprecedented 2 D[4+3]covalent organic frameworks(TTCOF-1,TTCOF-2,and TTCOF-3)have been prepared by substoichiometric condensation of tetratopic and tritopic monomers,overcoming the limitations of the design rules of conventional topologies.By reticulating the tetraphenylethylene(TPE)-based and triazine-based moieties into COF frameworks,novel electron donor-acceptor(D-A)type structures were obtained.These TTCOFs have good photocatalytic activity in aerobic C(sp3)–H bond functionalization and arylboronic acid oxidation driven by visible light,with yields up to 94%.This can expedite possibilities of COFs with new structural and topological complexities and can also expand the application of COF-based photocatalysis in synthetic chemistry.