A typical multicyclic branched-topology polystyrene (c-BPS) with high molecular weight (30 K ≤ Mw MALLS ≤ 300 K g mol-1) and narrow dispersity (1.2 ≤ Đ ≤ 1.3) was efficiently synthesized by combining atom transfer radical polymerization (ATRP) and atom transfer radical coupling (ATRC) techniques. The topological constraints imposed by the presence of cyclic units and branch points had a marked influence on the entanglement behaviors of the polymer chains in solution. Therefore, c-BPS possesses the lowest loss modulus (G'') and viscosity (η), the highest diffusion coefficient (D0), the largest mesh size (ξ) and the fastest terminal relaxation (TR), compared with branched and linear precursors.
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http://dx.doi.org/10.1039/d0cc07129c | DOI Listing |
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January 2025
Fujian Provincial Key Laboratory of Quantum Manipulation and New Energy Materials, College of Physics and Energy, Fujian Normal University, Fuzhou, Fujian, 350117, China.
Single-atom materials provide a platform to precisely regulate the electrochemical redox behavior of electrode materials with atomic level. Here, a multifield-regulated sintering route is reported to rapidly prepare single-atom zinc with a very high loading mass of 24.7 wt.
View Article and Find Full Text PDFIn biological systems, heme-copper oxidase (HCO) enzymes play a crucial role in the oxygen reduction reaction (ORR), where the pivotal O-O bond cleavage of the (heme)Fe-peroxo-Cu intermediate is facilitated by active-site (peroxo core) hydrogen bonding followed by proton-coupled electron transfer (PCET) from a nearby (phenolic) tyrosine residue. A useful approach to comprehend the fundamental relationships among H-bonding/proton/H-atom donors and their abilities to induce O-O bond homolysis involves the investigation of synthetic, bioinspired model systems where the exogenous substrate properties (such as p and bond dissociation energy (BDE)) can be systematically altered. This report details the reactivity of a heme-peroxo-copper HCO model complex (LS-4DCHIm) toward a series of substituted catechol substrates that span a range of p and O-H bond BDE values, exhibiting different reaction mechanisms.
View Article and Find Full Text PDFWe have employed a triazine-based conjugated polymer network (CPN) for the selective detection of hypochlorite in a semi-aqueous environment. CPNs have been widely employed in gas capture, separation, and adsorption, but the fluorescent properties of CPNs possessing extensive π-conjugated systems tend to be unexplored. Herein, we report the photophysical properties of the CPN and investigate its sensing capability towards hypochlorite.
View Article and Find Full Text PDFChemistry
January 2025
Manchester Interdisciplinary Biocentre: The University of Manchester Manchester Institute of Biotechnology, Biotechnology and chemical engineering, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Hypohalites are commonly generated in biological systems, mostly with functions related to defense and immune system response. These hypohalites can bind to metal centers and are known for their strong oxidizing properties that play crucial roles in various biological processes. Herein, we report the synthesis, characterization and reactivity of novel biomimetic Ru(III)-hypochlorite complexes and focus the work on the electronic effects associated with the incorporation of methyl groups in a pentadentate ligand framework in an asymmetric fashion.
View Article and Find Full Text PDFOrg Lett
January 2025
State Key Laboratory of Microbial Technology, Shandong University, 72 Binhai Road, Qingdao, Shandong 266237, P. R. China.
An anaerobic 1,2-/1,3-hydroxytrifluoromethylation of unactivated alkenes is described. This reaction proceeds in mild and environmentally friendly conditions without photocatalyst and metal catalyst, allowing access to a wide range of β- and γ-trifluoromethyl alcohols. Preliminary mechanistic investigations indicate that the accomplishment of this protocol relies on the dual functionality of the photoexcited triplet nitroarenes, which serve as the oxygen atom source and enable the single-electron transfer (SET) process with CFSONa.
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