Soft porous crystals, which are responsive to external stimuli such as temperature, pressure, or gas adsorption, are being extensively investigated for various technological applications. However, while substantial research has been devoted to stimuli-responsive metal-organic frameworks, structural flexibility in 3D covalent organic frameworks (COFs) remains ill-understood, and is almost exclusively found in COFs exhibiting the diamondoid (dia) topology. Herein, we systemically investigate how the structural decoration of these 3D dia COFs-their specific building blocks and degree of interpenetration-as well as external triggers such as temperature and guest adsorption may promote or suppress their phase transformations, as captured by a collection of 2D free energy landscapes. Together, these provide a comprehensive understanding of the necessary conditions to design flexible diamondoid COFs. This study reveals how their flexibility originates from the balance between steric hindrance and dispersive interactions of the structural decoration, thereby providing insight into how new flexible 3D COFs can be designed.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9822923 | PMC |
http://dx.doi.org/10.1038/s42004-022-00808-y | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Nankai University, School of Materials Science and Engineering, National Institute for Advanced Materials, TKL of Metal and Molecule-Based Material Chemistry, CHINA.
Efficient utilization of solar energy is widely regarded as a crucial solution to addressing the energy crisis and reducing reliance on fossil fuels. Coupling photothermal and photochemical conversion can effectively improve solar energy utilization yet remains challenging. Here, inspired by the photosynthesis system in green plants, we report herein an artificial solar energy converter (ASEC) composed of light-harvesting units as solar collector and oriented ionic hydrophilic channels as reactors and transporters.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
POLYMAT, University of the Basque Country UPV/EHU, Avenida de Tolosa 72, Donostia-San Sebastián 20018, Spain.
A challenging aspect in the synthesis of covalent organic frameworks (COFs) that goes beyond the framework's structure and topology is interpenetration, where two or more independent frameworks are mechanically interlocked with each other. Such interpenetrated or interlocked frameworks are commonly found in three-dimensional (3D) COFs with large pores. However, interlocked two-dimensional (2D) COFs are rarely seen in the literature, as 2D COF layers typically crystallize in stacks that maximize stabilization through π-stacking.
View Article and Find Full Text PDFChem Sci
December 2024
Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
Phosphorescent gold(iii) complexes possess long-lived emissive excited states, making them ideal for use as molecular sensors and photosensitizers for organic transformations. Literature reports indicate that gold(iii) emitters exhibit good catalytic activity in homogeneous photochemical reactions. Heterogeneous metal-organic framework (MOF)-supported gold(iii) photocatalysts are considered to show high recyclability in photochemical reactions and potentially provide new selectivities.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Westlake University, School of Engineering, 18 Shilongshan Road, 310024, Hangzhou, CHINA.
The Friedel-Crafts reaction has been extensively applied to the preparation of various porous organic polymers because of its simple operation and abundant building blocks. However, due to its poor reversibility and excessive random reactive sites, the synthesis of crystalline organic polymers/frameworks by Friedel-Crafts reaction has never been realized so far. Herein, we develop a molecular confined Friedel-Crafts reaction strategy to achieve rapid preparation (within only 30 minutes) of highly crystalline covalent triazine frameworks (CTFs) with tailorable functionality for the first time.
View Article and Find Full Text PDFACS Nano
January 2025
Shanghai Key Laboratory of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Siping Road 1239, Shanghai 200092, China.
The synthesis of covalent organic frameworks (COFs) with excellent luminescent properties and their effective application in the field of bionic sensing remain a formidable challenge. Herein, a series of COFs with different numbers of hydroxyl groups are successfully synthesized, and the number of hydroxyl groups on the benzene-1,3,5-tricarbaldehyde (BTA) linker influences the properties of the final COFs. The COF (HHBTA-OH) prepared with hydrazine hydrate (HH) and BTA containing one hydroxyl group as the ligands exhibits the best fluorescent performance.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!