Large pore donor-acceptor covalent organic frameworks

We report the synthesis and structural characterization of large pore covalent organic frameworks (COFs) integrated with donor and acceptor building blocks. The donor and acceptor, based on triphenylene and diimide, respectively, are topologically linked to form COFs with stacked donor and acceptor columns and 5.3 nm width channels, which show high crystallinity and large surface area. By varying donor-acceptor structure in conjunction with time-resolved spectroscopy, these large-pore COFs constitute benchmark frameworks to elucidate not only the importance of donor-acceptor pairing but also the role of lattice structure in charge transfer and separation, thereby casting a general principle for the structural design of optoelectronic and photovoltaic COFs.