Poly(1,2-dithiolane)s are a family of intrinsically recyclable polymers due to their dynamic covalent disulfide linkages. Despite the common use of thiolate-initiated anionic ring-opening polymerization (ROP) under basic condition, cationic ROP is still not exploited. Here we report that disulfide bond can act as a proton acceptor, being protonated by acids to form sulfonium cations, which can efficiently initiate the ROP of 1,2-dithiolanes and result in high-molecular-weight (over 1000 kDa) poly(disulfide)s. The reaction can be triggered by adding catalytic amounts of acids and non-coordinating anion salts, and completed in few minutes at room temperature. The acidic conditions allow the applicability for acidic monomers. Importantly, the reaction condition can be under open air without inert protection, enabling the nearly quantitative chemical recycling from bulk materials to original monomers.
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http://dx.doi.org/10.1002/anie.202215329 | DOI Listing |
Chembiochem
January 2025
Peking University, College of Chemistry and Molecular Engineering, No. 292 Chengfu Road, Haidian District, 100871, Beijing, CHINA.
Since the building blocks of DNA are nonfluorescent, various external fluorescence reporters have been employed to investigate the structure, dynamics, and function of DNA G-quadruplexes (GQs) and i-motifs (iMs), which play an important role in gene regulation and expression. However, most of those fluorescence reporters lack the ability to provide site-specific structural information of interest. Therefore, it is necessary to develop fluorescent nucleoside analogues that can be covalently inserted into oligonucleotides, which not only serve this purpose, but minimize any potential perturbation towards the native structure of the DNA systems in question.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Materials Department, University of California, Santa Barbara, Santa Barbara, California 93106, United States.
The insulating transition metal nitride CaCrN consists of sheets of triangular [CrN] units with symmetry that are connected via quasi-1D zigzag chains. Due to strong covalency between Cr and N, Cr ions are unusually low-spin, and = 1/2. Magnetic susceptibility measurements reveal dominant quasi-1D spin correlations with very large nearest-neighbor antiferromagnetic exchange = 340 K and yet no sign of magnetic order down to = 0.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
The Education Ministry Key Laboratory of Resource Chemistry, Shanghai Key Laboratory of Rare Earth Functional Materials, and Shanghai Municipal Education Committee Key Laboratory of Molecular Imaging Probes and Sensors, Shanghai Frontiers Science Research Base of Biomimetic Catalysis, Department of Chemistry, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China.
Supramolecular fluorescent materials with switchable behavior and induced luminescence enhancement are a new class of special materials for constructing fluorescence anti-counterfeiting materials. Since these materials are constructed by self-assembly through supramolecular host-guest interactions of non-covalent bonds, such fluorescent materials can regulate their optical properties through a reversible assembly-disassembly process. Inspired by the role of the β-barrel scaffold in activating strong fluorescence of a green fluorescent protein (GFP) chromophore, we designed a supramolecular system based on a novel GFP analogue (CA) and cucurbit[7]uril (CB[7]).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Sichuan University - Wangjiang Campus: Sichuan University, Polymer Research Institute, CHINA.
Covalent adaptable networks (CANs) offer innovative solutions for the reprocessing and recycling of thermoset polymers. However, achieving a balance between easy reprocessing and creep resistance remains a challenge. This study focuses on designing and synthesizing polyurethane (PU) materials with tailored properties by manipulating the stereochemistry of diamine chain extenders.
View Article and Find Full Text PDFActa Pharmacol Sin
January 2025
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, 201203, China.
The bromodomain (BRD) represents a highly conserved structural module that provides BRD proteins with fundamental functionality in modulating protein-protein interactions involved in diverse biological processes such as chromatin-mediated gene transcription, DNA recombination, replication and repair. Consequently, dysregulation of BRD proteins has been implicated in the pathogenesis of numerous human diseases. In recent years, considerable scientific endeavors have focused on unraveling the molecular mechanisms underlying BRDs and developing inhibitors that target these domains.
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