Although reticular chemistry has commonly utilized mutually embracing tetrahedral metal complexes as crossing points to generate three-dimensional molecularly woven structures, weaving in two dimensions remains largely unexplored. We report a new strategy to access 2D woven COFs by controlling the angle of the usually linear linker, resulting in the successful synthesis of a 2D woven pattern based on chain-link fence. The synthesis was accomplished by linking aldehyde-functionalized copper(I) bisphenanthroline complexes with bent 4,4'-oxydianiline building units. This results in the formation of a crystalline solid, termed COF-523-Cu, whose structure was characterized by spectroscopic techniques and electron and X-ray diffraction techniques to reveal a molecularly woven, twofold-interpenetrated chain-link fence. The present work significantly advances the concept of molecular weaving and its practice in the design of complex chemical structures.
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http://dx.doi.org/10.1021/jacs.3c09691 | DOI Listing |
Adv Mater
December 2024
Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK.
High contact resistance remains the primary obstacle that hinders further advancements of organic semiconductors (OSCs) in electronic circuits. While significant effort has been directed toward lowering the energy barrier at OSC/metal contact interfaces, approaches toward reducing another major contributor to overall contact resistance - the bulk resistance - have been limited to minimizing the thickness of OSC films. However, the out-of-plane conductivity of OSCs, a critical aspect of bulk resistance, has largely remained unaddressed.
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December 2024
State Key Laboratory of Structural Analysis, Optimization and CAE Software for Industrial Equipment, National Engineering Research Center for Advanced Polymer Processing Technology, Zhengzhou University, Zhengzhou, 450002, China.
Aerogel fibers uniting characteristics of both aerogels (lightweight and porosity) and fibers (flexibility and wearability) exhibit a great potential for the production of the next generation of thermal protection textiles; still, the complex drying procedures and mechanical brittleness remain the main obstacles toward further exploitation. Herein, flexible and robust aramid nanofiber aerogel fibers (ANAFs) are scalably prepared by continuous wet-spinning coupled with fast air-drying. This synthesis involves calcium ions (Ca⁺) cross-linking and solvent displacement by low surface tension solvents, to enhance skeleton strength and reduce the capillary force during evaporation, respectively, thus minimizing shrinkage to 29.
View Article and Find Full Text PDFCurr Opin Genet Dev
December 2024
Gladstone Institute for Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA, USA. Electronic address:
CCCTC-binding factor (CTCF) is a key regulator of 3D genome organization and transcriptional activity. Beyond its well-characterized role in facilitating cohesin-mediated loop extrusion, CTCF exhibits several cohesin-independent activities relevant to chromatin structure and various nuclear processes. These functions include patterning of nucleosome arrangement and chromatin accessibility through interactions with ATP-dependent chromatin remodelers.
View Article and Find Full Text PDFNMR Biomed
February 2025
High Field MR Center, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.
Deuterium metabolic imaging (DMI) is an emerging Magnetic Resonance technique providing valuable insight into the dynamics of cellular glucose (Glc) metabolism of the human brain in vivo using deuterium-labeled (H) glucose as non-invasive tracer. Reliable concentration estimation of H-Glc and downstream synthesized neurotransmitters glutamate + glutamine (Glx) requires accurate knowledge of relaxation times, but so far tissue-specific T and T relaxation times (e.g.
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December 2024
Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
The growing threat of electromagnetic pollution has become a pressing safety concern. Metal-organic framework (MOF) derivatives are considered ideal candidates for mitigating electromagnetic radiation. However, due to the limitations imposed by complex post-processing and disruption of pristine crystal structures, the mechanisms of electromagnetic wave absorption remain unclear, let alone achieving atomic-level regulation in MOF derivatives.
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