Recent Advances in Heterocyclic Nanographenes and Other Polycyclic Heteroaromatic Compounds

Chemical Reviews, Journal Year: 2021, Volume and Issue: 122(1), P. 565 - 788

Published: Dec. 1, 2021

This review surveys recent progress in the chemistry of polycyclic heteroaromatic molecules with a focus on structural diversity and synthetic methodology. The article covers literature published during period 2016-2020, providing an update to our first this topic (

Language: Английский

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Two-Dimensional Covalent Organic Frameworks with Cobalt(II)-Phthalocyanine Sites for Efficient Electrocatalytic Carbon Dioxide Reduction

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(18), P. 7104 - 7113

Published: May 3, 2021

The rapid development in synthesis methodology and applications for covalent organic frameworks (COFs) has been witnessed recent years. However, the of highly stable functional COFs still remains a great challenge. Herein two-dimensional polyimide-linked phthalocyanine (denoted as CoPc-PI-COF-1 CoPc-PI-COF-2) have devised prepared through solvothermal reaction tetraanhydrides 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato cobalt(II) with 1,4-phenylenediamine 4,4′-biphenyldiamine, respectively. resultant CoPc-PI-COFs four-connected sql net exhibit AA stacking configurations according to powder X-ray diffraction studies, showing permanent porosity, thermal stability above 300 °C, excellent resistance 12 M HCl aqueous solution 20 days. Current–voltage curves reveal conductivity CoPc-PI-COF-2 value 3.7 × 10–3 1.6 S m–1, Due same Co(II) electroactive sites together similar porosity CO2 adsorption capacity CoPc-PI-COFs, cathodes made up carbon black display CO2-to-CO Faradaic efficiency 87–97% at applied potentials between −0.60 −0.90 V (vs RHE) 0.5 KHCO3 solution. comparison CoPc-PI-COF-2&carbon electrode, counterpart provides larger current density (jCO) −21.2 mA cm–2 associated its higher conductivity. This cathode also high turnover number frequency, amounting 277 000 2.2 s–1 −0.70 during 40 h measurement. present result clearly discloses potential 2D porous crystalline solids electrocatalysis.

Language: Английский

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Platinum Single Atoms Anchored on a Covalent Organic Framework: Boosting Active Sites for Photocatalytic Hydrogen Evolution

ACS Catalysis, Journal Year: 2021, Volume and Issue: 11(21), P. 13266 - 13279

Published: Oct. 18, 2021

It is of great importance to explore and achieve a more effective approach toward the controllable synthesis single-atom-based photocatalysts with high metal content long-term durability. Herein, single-atom platinum (Pt) loading anchored on pore walls two-dimensional β-ketoenamine-linked covalent organic frameworks (TpPa-1-COF) presented. Aided by advanced characterization techniques aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (AC HAADF-STEM) X-ray absorption fine structure (XAFS) spectroscopy, it has been demonstrated that atomically dispersed Pt formed TpPa-1-COF support through six-coordinated C3N–Pt–Cl2 species. The optimized Pt1@TpPa-1 catalyst exhibits photocatalytic H2 evolution rate 719 μmol g–1 h–1 under visible-light irradiation, actual 0.72 wt %, large turnover frequency (TOF) 19.5 h–1, activity equivalent 3.9 48 times higher than those nanoparticles/TpPa-1 bare TpPa-1, respectively. improved performance for ascribed photogenerated charge separation migration well-dispersed active sites Pt. Moreover, density functional theory (DFT) calculations further reveal role single atoms in enhanced evolution. Overall, this work provides some inspiration designing outstanding stability efficiency using COFs as support.

Language: Английский

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Stable Bimetallic Polyphthalocyanine Covalent Organic Frameworks as Superior Electrocatalysts

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(43), P. 18052 - 18060

Published: Oct. 12, 2021

The development of highly stable covalent organic frameworks (COFs) is extremely compelling for their implementation in practical application. In this work, we rationally designed and synthesized new kinds ultrastable bimetallic polyphthalocyanine COFs, which are constructed with the dioxin linkage through nucleophilic aromatic substitution between octahydroxylphthalocyanine hexadecafluorophthalocyanine. resulting CuPcF8-CoPc-COF CuPcF8-CoNPc-COF exhibited strong robustness under harsh conditions. eclipsed stacking mode metallophthalocyanine units supplies a high-speed pathway electron transfer. With these structural advantages, both COFs displayed considerable activity, selectivity, stability toward electrocatalytic CO2 reduction an aqueous system. Notably, showed faradaic efficiency 97% exceptionally high turnover frequency 2.87 s-1, superior to most COF-based electrocatalysts. Furthermore, catalytic mechanism was well demonstrated by using theoretical calculation. This work not only expanded variety dioxin-linked but also constituted step use carbon cycle.

Language: Английский

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Piperazine-Linked Covalent Organic Frameworks with High Electrical Conductivity

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(7), P. 2873 - 2878

Published: Feb. 7, 2022

A new kind of piperazine-linked covalent organic framework (COF) was synthesized through the nucleophilic substitution reaction between octaminophthalocyanines and hexadecafluorophthalocyanines. The two-dimensional (2D) frameworks are in tetragonally shaped polygon sheets, which stack an AA stacking mode to constitute periodically ordered metallophthalocyanine columns one-dimensional (1D) microporous channels. COFs exhibit excellent chemical stability permanent porosity. By virtue neatly arrayed phthalocyanine inbuilt cationic radicals, highly conductive. conductivity values NiPc-NH-CoPcF8 COF reached up 2.72 12.7 S m-1 for pellet film samples, respectively. Moreover, this p-type conductive exhibited a high carrier mobility 35.4 cm2 V-1 s-1. Both electric set records COFs.

Language: Английский

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2D Covalent Organic Frameworks: From Synthetic Strategies to Advanced Optical‐Electrical‐Magnetic Functionalities

Advanced Materials, Journal Year: 2022, Volume and Issue: 34(17)

Published: Jan. 20, 2022

Abstract Covalent organic frameworks (COFs), an emerging class of crystalline polymers with highly oriented structures and permanent porosity, can adopt 2D or 3D architectures depending on the different topological diagrams monomers. Notably, COFs have particularly gained much attention due to extraordinary merits their extended in‐plane π‐conjugation topologically ordered columnar π‐arrays. These properties together high crystallinity, large surface area, tunable porosity distinguish as ideal candidate for fabrication functional materials. Herein, this review surveys recent research advances in special emphasis preparation COF powders, single crystals, thin films, well advanced optical, electrical, magnetic functionalities. Some challenging issues potential outlook are also provided promoting development terms structure, synthesis,

Language: Английский

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Stimuli-Responsive Crystalline Smart Materials: From Rational Design and Fabrication to Applications

Accounts of Chemical Research, Journal Year: 2022, Volume and Issue: 55(7), P. 1047 - 1058

Published: March 16, 2022

Stimuli-responsive smart materials that can undergo reversible chemical/physical changes under external stimuli such as mechanical stress, heat, light, gas, electricity, and pH, are currently attracting increasing attention in the fields of sensors, actuators, optoelectronic devices, information storage, medical applications, so forth. The current mostly concentrate on polymers, carbon materials, crystalline liquids, hydrogels, which have no or low structural order (i.e., responsive groups/moieties disorderly structures), inevitably introducing deficiencies a relatively response speeds, energy transformation inefficiencies, unclear structure-property relationships. Consequently, with well-defined regular molecular arrays offer new opportunity to create novel improved stimuli-responsive performance. Crystalline include framework (e.g., metal-organic frameworks, MOFs; covalent organic COFs) crystals molecules cages), obvious advantages compared amorphous materials. For example, be uniformly installed skeleton crystal form ordered arrays, making transfer between external-stimulus signals sites much faster more efficiently. Besides that, structures facilitate situ characterization their at level by means various techniques high-tech equipment spectra single-crystal/powder X-ray diffraction, thus benefiting investigation understanding mechanism behind behaviors Nevertheless, some unsolved challenges remain for (CSMs), hampering fabrication material systems practical applications. instance, materials' crystallinity increases, processability properties usually decrease, unavoidably hindering application. Moreover, exist micro/nanosized powders, difficult make macroscale. Thus, developing strategies balance establishing macroscale great significance applications.In this Account, we mainly summarize recent research progress achieved our groups, including (i) rational design an in-depth relationship (ii) creating modification improve Overall, Account summarizes state-of-the-art points out existing future development directions field.

Language: Английский

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The electrical conductivity of solution-processed nanosheet networks

Nature Reviews Materials, Journal Year: 2021, Volume and Issue: 7(3), P. 217 - 234

Published: Nov. 9, 2021

Language: Английский

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Ionic Covalent Organic Frameworks for Energy Devices

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(52)

Published: Oct. 8, 2021

Covalent organic frameworks (COFs) are a class of porous crystalline materials whose facile preparation, functionality, and modularity have led to their becoming powerful platforms for the development molecular devices in many fields (bio)engineering, such as energy storage, environmental remediation, drug delivery, catalysis. In particular, ionic COFs (iCOFs) highly useful constructing devices, functional groups can transport ions efficiently, nonlabile ordered all-covalent pore structures backbones provide ideal pathways long-term under harsh electrochemical conditions. Here, current research progress on use iCOFs specifically lithium-based batteries fuel cells, is reviewed terms iCOF backbone-design strategies, synthetic approaches, properties, engineering techniques, applications. categorized anionic or cationic COFs, how each these types lithium ions, protons, hydroxides illustrated. Finally, challenges future opportunities utilization described. This review will therefore serve reference state-of-the-art design application strategies focusing devices.

Language: Английский

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A Three-Dimensional sp² Carbon-Conjugated Covalent Organic Framework

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(38), P. 15562 - 15566

Published: Sept. 17, 2021

A first example of an sp2 carbon-conjugated three-dimensional (3D) covalent organic framework (COF) (BUCT-COF-4) is synthesized via the Knoevenagel condensation saddle-shaped aldehyde-substituted cyclooctatetrathiophene and 1,4-phenylenediacetonitrile. Ascribed to extended π-conjugation long-range ordered structures, BUCT-COF-4 displays high Hall electron mobility 1.97 cm2 V–1 s–1 at room temperature. After it doped with iodine, material not only exhibits enhanced up 2.62 in ambient air but also presents unexpected metal-free ferromagnetic phase transition arising from formation aligned spins unidirectional across whole 3D framework. This report a phenomenon COF materials, which would broaden promising applications open new frontier materials.

Language: Английский

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