A series of magnesium carboxylate complexes containing intramolecular NH···O hydrogen bonds were synthesized. Their molecular structures were determined by X-ray analysis. A direct NH···O hydrogen bond to the coordinated oxygen atom elongated the Mg-O bond, while a hydrogen bond to the carbonyl group shortened the Mg-O bond. Double NH···O hydrogen bonds significantly lowered the basicity of the carboxylate anion and prevented coordination to the Mg ion in a trans configuration; however, a cis-dicarboxylate complex was successfully obtained. Strong coordination of water to the Mg(2+) ion stabilizes the weak Mg-carboxylate bond at the trans position. In contrast, a weak Mg-carboxylate bond strengthens the Mg-O(water) bond, probably increasing the acidity. Based on the experimental results and theoretical calculations, a new switching mechanism is proposed. In the proposed mechanism, the acidity of the coordinated water on magnesium is controlled during catalytic hydrolysis in endonuclease.
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ACS Nano
January 2025
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Transition-metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS), have emerged as a generation of nonprecious catalysts for the hydrogen evolution reaction (HER), largely due to their theoretical hydrogen adsorption energy close to that of platinum. However, efforts to activate the basal planes of TMDs have primarily centered around strategies such as introducing numerous atomic vacancies, creating vacancy-heteroatom complexes, or applying significant strain, especially for acidic media. These approaches, while potentially effective, present substantial challenges in practical large-scale deployment.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Xihua University, Chengdu 610039, P. R. China.
A novel approach for the synthesis of pyrone and indanone derivatives utilizing Fe(III)-catalyzed reductive radical ring expansion of olefins and cyclopropenone has been proposed. The preliminary mechanism study shows that the alkyl radical is formed by hydrogen atom transfer, which can open the tension ring and then generate the intermediate. There are two paths for the intermediate: when there is a hydroxyl group at the β-position of the olefin, the reaction produces pyrones, and otherwise 1-indanone is generated.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen 361005, China.
Nitrogen fixation is essential for the sustainable development of both human society and the environment. Due to the chemical inertness of the N≡N bond, the traditional Haber-Bosch process operates under extreme conditions, making nitrogen fixation under ambient conditions highly desirable but challenging. In this study, we present an ultrasonic atomizing microdroplet method that achieves nitrogen fixation using water and air under ambient conditions in a rationally designed sealed device, without the need for any catalyst.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Center for Molecular Spectroscopy and Dynamics, Institute for Basic Science, Seoul 02841, Korea.
ConspectusWater-in-salt electrolytes (WiSEs) are promising electrolytes for next-generation lithium-ion batteries (LIBs), offering critical advantages like nonflammability and improved safety. These electrolytes have extremely high salt concentrations and exhibit unique solvation structures and transport mechanisms dominated by the formation of ion networks and aggregates. These ion networks are central to the performance of WiSEs, govern the transport properties and stability of the electrolyte, deviating from conventional dilute aqueous or organic electrolytes.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Key Laboratory of Carbon Materials of Zhejiang Province, Wenzhou University, Wenzhou 325035, China.
Developing high-energy-density lithium-sulfur batteries faces serious polysulfide shuttle effects and sluggish conversion kinetics, often necessitating the excessive use of electrolytes, which in turn adversely affects battery performance. Our study introduces a meticulously designed electrocatalyst, Cu-CeO@N/C, to enhance lean-electrolyte lithium-sulfur battery performance. This catalyst, featuring in situ synthesized Cu clusters, regulates oxygen vacancies in CeO and forms Cu-CeO heterojunctions, thereby diminishing sulfur conversion barriers and hastening reaction kinetics through the generation of S/S intermediates.
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