Porous Crystalline Nitrone-Linked Covalent Organic Framework

Herein, we report the synthesis of a nitrone-linked covalent organic framework, COF-115, by combining N, N', N', N'''-(ethene-1,1,2,2-tetrayltetrakis(benzene-4,1-diyl))tetrakis(hydroxylamine) and terephthaladehyde via a polycon-densation reaction. The formation of the nitrone functionality was confirmed by solid-state 13C multi cross-polarization magic angle spinning NMR spectroscopy of the 13C-isotope-labeled COF-115 and Fourier-transform infra-red spectroscopy. The permanent porosity of COF-115 was evaluated through low-pressure N2, CO2, and H2 sorption experiments. Water vapor and carbon dioxide sorption analysis of COF-115 and the isoreticular imine-linked COF indicated a superior potential of N-oxide-based porous materials for atmospheric water harvesting and CO2 capture applications, respectively. Lastly, photoinduced rearrangement of COF-115 to the associated amide-linked material was successfully demonstrated.