A Spirobifluorene-Based Covalent Organic Framework for Dual Photoredox and Nickel Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(46), P. 25074 - 25079

Published: Nov. 7, 2023

Covalent organic frameworks (COFs) have emerged as tunable, crystalline, and porous functional materials, but their application in photocatalysis has been limited by rapid excited-state quenching. Herein, we report the first example of dual photoredox/nickel catalysis an sp2 carbon-conjugated spirobifluorene-based COF. Constructed from spirobifluorene nickel-bipyridine linkers, NiSCN COF adopted a two-dimensional structure with staggered stacking. Under light irradiation, catalyzed amination etherification/esterification reactions aryl halides through photoredox mechanism, catalytic efficiency more than 23-fold higher that its homogeneous control. was used five consecutive without significant loss activity.

Language: Английский

---

A Review on Covalent Organic Frameworks as Artificial Interface Layers for Li and Zn Metal Anodes in Rechargeable Batteries

Advanced Science, Journal Year: 2023, Volume and Issue: 11(7)

Published: Dec. 8, 2023

Abstract Li and Zn metals are considered promising negative electrode materials for the next generation of rechargeable metal batteries because their non‐toxicity high theoretical capacity. However, uneven deposition ions (Li + , 2+ ) uncontrolled growth dendrites result in poor electrochemical stability, unsatisfactory cycle life, rapid capacity decay assembled with electrodes. Owing to unique internal directional channels abundant redox active sites covalent organic frameworks (COFs), they can be used promote uniform during stripping/electroplating through interface modification strategies, thereby inhibiting dendrite growth. COFs provide a new perspective addressing challenges faced by anodes ion batteries. This article discusses stability types COFs, summarizes some novel COF synthesis methods. Additionally, it reviews latest progress optimization methods using improve battery performance. Finally, main these areas discussed. review will inspire future research on

Language: Английский

---

Employing Singlet Fission into Boosting the Generation of Singlet Oxygen and Superoxide Radicals for Photooxidation Reactions

ACS Catalysis, Journal Year: 2023, Volume and Issue: 13(21), P. 13902 - 13911

Published: Oct. 13, 2023

Developing highly efficient heavy-metal-free photosensitizers (PSs) for the production of reactive oxygen species (ROS) is urgent to achieve wide applications ROS, yet it remains a great challenge. As proof concept, singlet fission (SF), possessing exciton multiplication ability with maximum 200% triplet yield, employed generate ROS. Herein, metal-free tetracene dimer high yield (∼164%) long-lived triplets (>300 μs) prepared and used (1O2) superoxide radicals (O2·–). Remarkably, 1O2 O2·– yields are boosted compared existing traditional PSs based on intersystem crossing (ISC). The reaches an unprecedented ∼148%, representing highest value ever reported so far. Thus, this SF PS shows improved photooxidation activity over ISC PSs. Additionally, generation mechanisms described clearly by combining TA spectra controlled experiments. This represents first example utilizing two states produced ROS catalyze related reactions. work not only presents strategy generating enhancing 1O2/O2·– but also opens up new field application SF.

Language: Английский

---

Observation of Interpenetrated Topology Isomerism for Covalent Organic Frameworks with Atom-Resolution Single Crystal Structures

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(46), P. 25332 - 25340

Published: Nov. 9, 2023

Rational control and understanding of isomerism are significance but still remain a great challenge in reticular frameworks, particular, for covalent organic frameworks (COFs) due to the complicated synthesis energy factors. Herein, reaction 3,3′,5,5′-tetra(4-formylphenyl)-2,2′,6,6′-tetramethoxy-1,1′-biphenyl (TFTB) with 3,3′,5,5′-tetrakis(4-aminophenyl)bimesityl (TAPB) under different conditions affords single crystals two 3D COF isomers, namely, USTB-20-dia USTB-20-qtz. Their structures resolutions up 0.9–1.1 Å have been directly solved by three-dimensional electron diffraction (3D ED) synchrotron crystal X-ray diffraction, respectively. USTB-20-qtz show rare 2 × 2-fold interpenetrated dia-b nets 3-fold qtz-b frameworks. Comparative studies these COFs theoretical simulation results indicate crucial role flexible molecular configurations building blocks present topology isomerism. This work not only presents isomers also gains an formation framework from both perspectives.

Language: Английский

---

Single-Crystalline 3D Covalent Organic Frameworks with Exceptionally High Specific Surface Areas and Gas Storage Capacities

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(42), P. 28932 - 28940

Published: Oct. 11, 2024

Single-crystalline covalent organic frameworks (COFs) are highly desirable toward understanding their pore chemistry and functions. Herein, two 50–100 μm single-crystalline three-dimensional (3D) COFs, TAM-TFPB-COF TAPB-TFS-COF, were prepared from the condensation of 4,4′,4″,4‴-methanetetrayltetraaniline (TAM) with 3,3′,5,5′-tetrakis(4-formylphenyl)bimesityl (TFPB) 3,3′,5,5′-tetrakis(4-aminophenyl)bimesityl (TAPB) 4,4′,4″,4‴-silanetetrayltetrabenzaldehyde (TFS), respectively, in 1,4-dioxane under catalysis acetic acid. Single-crystal 3D electron diffraction reveals triply interpenetrated dia-b networks atom resolution, while isostructure TAPB-TFS-COF was disclosed by synchrotron single-crystal X-ray powder Le Bail refinements. The nitrogen sorption measurements at 77 K disclose microporosity nature both activated COFs exceptionally high Brunauer–Emmett–Teller surface areas 3533 4107 m2 g–1, representing thus far record specific area among imine-bonded COFs. This enables to exhibit also methane uptake capacities up 28.9 wt % (570 cm3 g–1) 25 °C 200 bar all reported far. work not only presents structures exceptional but provides an example engineering adjust permanent microporous for storage.

Language: Английский

---

Advances of functionalized bipyridine-based covalent-organic frameworks for boosting photocatalysis

Coordination Chemistry Reviews, Journal Year: 2024, Volume and Issue: 516, P. 215997 - 215997

Published: June 5, 2024

Language: Английский

---

NPh₃-Mediated WO₃-Photocatalyzed Semiheterogeneous Hydroxylation of Aryl and Alkyl Boronic Acids

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(15), P. 10654 - 10659

Published: July 17, 2024

With an inexpensive and commercially available WO

Language: Английский

---

Single Cobalt Ion-Immobilized Covalent Organic Framework for Lithium–Sulfur Batteries with Enhanced Rate Capabilities

ACS Applied Materials & Interfaces, Journal Year: 2024, Volume and Issue: 16(4), P. 4741 - 4750

Published: Jan. 19, 2024

Covalent organic frameworks (COFs) are notable for their remarkable structure, function designability, and tailorability, as well stability, the introduction of "open metal sites" ensures efficient binding small molecules activation substrates heterogeneous catalysis energy storage. Herein, we use postsynthetic sites to catalyze polysulfide conversion boost affinity active matter lithium–sulfur batteries (LSBs). A dual-pore COF, USTB-27, with hxl topology has been successfully assembled from imine chemical reaction between 2,3,8,9,14,15-hexa(4-formylphenyl)diquinoxalino [2,3-a:2′,3′-c]phenazine [2,2′-bipyridine]-5,5′-diamine. The chelating nitrogen both modules able postsynthetically functionalize single cobalt generate USTB-27-Co. discharge capacity sulfur-loaded S@USTB-27-Co composite in a LSB is 1063, 945, 836, 765, 696, 644 mA h g–1 at current densities 0.1, 0.2, 0.5, 1.0, 2.0, 5.0 C, respectively, much superior that non-cobalt-functionalized species S@USTB-27. Following increased densities, rate performance better than In particular, retention C magnificent increase 19% latter 61% former one. Moreover, exhibits higher specific 543 S@USTB-27 (402 g–1) density 1.0 after electrochemical cycling 500 runs. This work illustrates strategy engineer component COF channels strength applications.

Language: Английский

---

Linkage Microenvironment Modulation in Triazine‐Based Covalent Organic Frameworks for Enhanced Photocatalytic Hydrogen Peroxide Production

Small, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 26, 2025

Abstract Covalent organic frameworks (COFs), known for the precise tunability of molecular structures, hold significant promise photocatalytic hydrogen peroxide (H 2 O ) production. Herein, by systematically altering quinoline (QN) linkages in triazine (TA)‐based COFs via multi‐component reactions, six R‐QN‐TA‐COFs are synthesized with identical skeletons but different substituents. The fine‐tuning optoelectronic properties and local microenvironment is allowed, thereby optimizing charge separation improving interactions dissolved oxygen. Consequently, MeO‐QN‐TA‐COF customized to achieve an impressive rate H production up 7384 µmol g⁻ 1 h⁻ under air atmosphere water without any sacrificial agents, surpassing most reported COF photocatalysts. Its high stability demonstrated through five consecutive recycling experiments characterization recovered COF. reaction mechanism further investigated using a suite quenching experiments, situ spectroscopic analysis, theoretical calculations. enhanced over 2e⁻ oxygen reduction oxidation pathways. Overall, crucial role linkage modulation design solar‐driven effective

Language: Английский

---

Recent Advances in Room-Temperature Synthesis of Covalent Organic Frameworks

Chemical Science, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Room-temperature synthesis bridges the gap between chemistry and practical application of COFs. This review provides an overview characterization technologies COF growth mechanisms recent room-temperature synthetic strategies.

Language: Английский

---