The p K(a)'s of the 6-CH groups of N-methyl-2-methoxypyridinium, N-methyl-4-methoxypyridinium, and 1-methyl-2,4-dimethoxypyrimidinium ions in aqueous solution were determined to be about 33. The p K(a) values were nearly identical to each other and surprisingly similar to those reported for the neutral pyridones and uracil. Further determination of the enthalpies and entropies of the H-D exchange reactions revealed the role of solvation.
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http://dx.doi.org/10.1021/ol800892d | DOI Listing |
Precis Chem
December 2024
State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
The interfacial proton transfer (PT) reaction on the metal oxide surface is an important step in many chemical processes including photoelectrocatalytic water splitting, dehydrogenation, and hydrogen storage. The investigation of the PT process, in terms of thermodynamics and kinetics, has received considerable attention, but the individual free energy barriers and solvent effects for different PT pathways on rutile oxide are still lacking. Here, by applying a combination of ab initio and deep potential molecular dynamics methods, we have studied interfacial PT mechanisms by selecting the rutile SnO(110)/HO interface as an example of an oxide with the characteristic of frequently interfacial PT processes.
View Article and Find Full Text PDFJ Mol Model
December 2024
Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Avenida Ferrocarril San Rafael Atlixco, Número 186, Colonia Leyes de Reforma 1A Sección, Alcaldía Iztapalapa, Código Postal 09310, Ciudad de Mexico, Mexico.
Context: Antioxidants are known to play a beneficial role in human health. Caffeic acid has been previously recognized as efficient in this context. However, such a capability can be enhanced through structural modification.
View Article and Find Full Text PDFAdv Mater
December 2024
Department of Chemistry, Pohang University of Science and Technology (POSTECH), 37673, Pohang, Republic of Korea.
Water is pursued as an electrolyte solvent for its non-flammable nature compared to traditional organic solvents, yet its narrow electrochemical stability window (ESW) limits its performance. Solvation chemistry design is widely adopted as the key to suppress the reactivity of water, thereby expanding the ESW. In this study, an acetamide-based ternary eutectic electrolyte achieved an ESW ranging from 1.
View Article and Find Full Text PDFLangmuir
December 2024
Department of Architectural Engineering, Hanyang University ERICA, 55 Hanyangdaehak-ro, Sangrok-gu, Ansan-si 15588, Gyeonggi-do, Republic of Korea.
Reliable corrosion inhibition systems are crucial for extending the lifespan of industrial metal structures. Quinolines, with their high adsorption capacity and protective efficiency, are promising next-generation inhibitors. However, the impact of substitutions on their coordination with iron surfaces requires deeper understanding.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States.
Direct air capture (DAC) technologies are limited by the poor understanding of the dynamic role of interfaces in modulating the chemisorption of CO from air into solutions. While the reactivity of aqueous amine-based solvents in the bulk environment is strongly inhibited by nonequilibrium solvent effects, promoting DAC at interfaces posits a possibility to reduce the coupling with the solvent and significantly accelerate DAC. Building on an experimentally proven concept to bring an anionic glycine absorbent to the interface through ion-pairing interactions with a positively charged surfactant, we establish the fundamental time scales for key elementary steps involved in DAC with rate theory and enhanced-sampling molecular dynamics simulations.
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