Development of porous materials combining stability and high performance has remained a challenge. This is particularly true for proton-transporting materials essential for applications in sensing, catalysis and energy conversion and storage. Here we report the topology guided synthesis of an imine-bonded (C=N) dually stable covalent organic framework to construct dense yet aligned one-dimensional nanochannels, in which the linkers induce hyperconjugation and inductive effects to stabilize the pore structure and the nitrogen sites on pore walls confine and stabilize the H 3 PO 4 network in the channels via hydrogen-bonding interactions. The resulting materials enable proton super flow to enhance rates by 2-8 orders of magnitude compared to other analogues. Temperature profile and molecular dynamics reveal proton hopping at low activation and reorganization energies with greatly enhanced mobility.

Pore surface engineering of ultrathin COF membranes by introducing different lengths of alkyl chains into the skeleton, which allows us to precisely control the pore size of COF membranes for OSN applications and molecular sieving.

Covalent organic frameworks (COFs) offer great potential for various advanced applications such as photocatalysis, sensing, etc., because of their fully conjugated, porous, and chemically stable unique structural architecture. In this work, we have designed and developed a truxene based ultrastable COF (Tx-COF-2) by Schiff-base condensation between 1,3,5-Tris(4-aminophenyl)benzene (TAPB) and 5,5,10,10,15,15-hexamethyl-10,15-dihydro-5H-diindeno(1,2-a:1',2'-c)fluorene-2,7,12-tricarbaldehyde (Tx-CHO) for the first time. The resulting COF possesses excellent crystallinity, permanent porosity, and high Brunauer-Emmett-Teller (BET) surface areas (up to 1137 m 2 g -1 ). The COF was found to be a heterogeneous, recyclable photocatalyst for efficient conversion of arylboronic acids to phenols under visible-light irradiation, an environmentally friendly alternative approach to conventional metalbased photocatalysis. Besides, Tx-COF-2 provides an immediate naked-eye color change (<1s) and fluorescence 'turn-on' phenomena upon exposure to HCl. The response is highly sensitive, with an ultra-low detection limit of up to 4.5 nmol L -1 .

Covalent organic frameworks (COFs) have emerged as a new class of crystalline porous materials with distinct structural features, such as uniform pore distribution, tunable architecture, and modifiable skeletons. COFs hold...

Elucidating the precise stacking configuration of a covalent organic framework, COF, is critical to fully understand their various applications. Unfortunately, most COFs form powder crystals whose atomic characterisations are possible...

Exploring a covalent organic framework (COF) material as an efficient metal-free photocatalyst and as an adsorbent for the removal of pollutants from contaminated water is very challenging in the context of sustainable chemistry. Herein, we report a new porous crystalline COF, C6-TRZ-TPA COF, via segregation of donor–acceptor moieties through the extended Schiff base condensation between tris(4-formylphenyl)amine and 4,4′,4″-(1,3,5-triazine-2,4,6-triyl)trianiline. This COF displayed a Brunauer–Emmett–Teller (BET) surface area of 1058 m2 g–1 with a pore volume of 0.73 cc g–1. Again, extended π-conjugation, the presence of heteroatoms throughout the framework, and a narrow band gap of 2.2 eV, all these features collectively work for the environmental remediation in two different perspectives: it could harness solar energy for environmental clean-up, where the COF has been explored as a robust metal-free photocatalyst for wastewater treatment and as an adsorbent for iodine capture. In our endeavor of wastewater treatment, we have conducted the photodegradation of rose bengal (RB) and methylene blue (MB) as model pollutants since these are extremely toxic, are health hazard, and bioaccumulative in nature. The catalyst C6-TRZ-TPA COF showed a very high catalytic efficiency of 99% towards the degradation of 250 parts per million (ppm) of RB solution in 80 min under visible light irradiation with the rate constant of 0.05 min–1. Further, C6-TRZ-TPA COF is found to be an excellent adsorbent as it efficiently adsorbed radioactive iodine from its solution as well as from the vapor phase. The material exhibits a very rapid iodine capturing tendency with an outstanding iodine vapor uptake capacity of 4832 mg g–1.

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2The Mallory (photocyclization) and Scholl (thermal cyclohydrogenation) reactions