We report a new synthetic protocol for preparing highly ordered two-dimensional nanoporous covalent organic frameworks (2D-COFs) based on a quinoxaline backbone. The quinoxaline framework represents a new type of COF that enables postsynthetic modification by placing two different chemical functionalities within the nanopores including layer-to-layer cross-linking. We also demonstrate that membranes fabricated using this new 2D-COF perform highly selective separations resulting in dramatic performance enhancement post cross-linking.
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http://dx.doi.org/10.1021/acsami.1c08854 | DOI Listing |
Talanta
January 2025
State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, China. Electronic address:
Flavonoid glycosides are formed by dehydration condensation of aglycones and sugar molecules. Therefore, discrimination of flavonoid glycosides from their corresponding aglycones is a challenging task because they contain the same aglycone part in their molecular structures. Herein, boric acid-functional Eu(III)-organic framework (BA-Eu-MOF) was applied to discriminate flavonoid glycosides including baicalin (Bai), wogonoside (Wog), rutin (Rut), puerarin (Pue), quercitrin (Que) and astragalin (Ast) from their corresponding aglycones for the first time.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Institute of Materials Research and Engineering, Sensor and Flexible Electronics, 2 Fusionopolis Way, 138634, SINGAPORE.
Radical covalent organic frameworks (RCOFs) have demonstrated significant potential in redox catalysis and energy conversion applications. However, the synthesis of stable RCOFs with well-defined neutral carbon radical centers is challenging due to the inherent radical instability, limited synthetic methods and characterization difficulties. Building upon the understanding of stable carbon radicals and structural modulations for preparing crystalline COFs, herein we report the synthesis of a crystalline carbon-centered RCOF through a facile post-oxidation process.
View Article and Find Full Text PDFSmall
January 2025
School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, 646000, China.
Covalent organic frameworks (COFs), known for their exceptional in situ encapsulation and precise release capabilities, are emerging as pioneering drug delivery systems. This study introduces a hypoxia-responsive COF designed to encapsulate the chemotherapy drug gambogic acid (GA) in situ. Bimetallic gold-palladium islands were grown on UiO-66-NH (UiO) to form UiO@Au-Pd (UAPi), which were encapsulated with GA through COF membrane formation, resulting in a core-shell structure (UAPiGC).
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Chemistry, Chemical Engineering and Materials Science, Shandong Normal University, Jinan 250014, China. Electronic address:
Covalent organic frameworks (COFs) with highly ordered structures and predictable optoelectronic properties provide an ideal platform to investigate the electrochemiluminescence (ECL) performance based on organic materials by atomically varying the molecular construction. Herein, the effect of imine-bond orientation on the ECL performance of COFs is investigated. We report two COFs (NC-COF and CN-COF) with different orientations of imine bonds using pyrene donor units (D) and bipyridine acceptor motifs (A) monomers.
View Article and Find Full Text PDFChem Sci
January 2025
Hunan Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University Changsha 410083 P. R. China
The layer-stacking mode of a two-dimensional (2D) material plays a dominant role either in its topology or properties, but remains challenging to control. Herein, we developed alkali-metal ion-regulating synthetic control on the stacking structure of a vinylene-linked covalent triazine framework (termed spc-CTF) for improving hydrogen peroxide (HO) photoproduction. Upon the catalysis of EtONa in Knoevenagel polycondensation, a typical eclipsed stacking mode (spc-CTF-4@AA) was built, while a staggered one (spc-CTF-4@AB) was constructed using LiOH.
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