Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/physrevb.42.5677 | DOI Listing |
Nat Commun
January 2025
Faculty of Materials Science and Engineering, Kunming University of Science and Technology, 650093, Kunming, PR China.
Regulating carbon hybridization states lies at the heart of engineering carbon materials with tailored properties but orchestrating the sequential transition across three states has remained elusive. Here, we visiualize stepwise evolution in carbon hybridizations from sp³ to sp² and to sp states via dehydrogenation and elimination reactions of methylcyano-functionalized molecules on surfaces. Utilizing scanning probing microscopy, we distinguish three distinct carbon-carbon bond types within polymers induced by annealing at elevated temperatures.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
School of Chemistry & Chemical Engineering, Anhui University, Hefei, Anhui 230601, PR China.
Superatoms are stable clusters that mimic the chemical behavior of individual atoms in the periodic table. Many endeavors have been devoted to the design and characterization of various superatoms, while engineering superatoms to mimic the chemistry of chalcogens remains a challenge. In this paper, we present a new superchalcogen by evaluating a hollow tetrahedral AlO cluster with theoretical calculations.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Dipartimento di Scienze Fisiche e Chimiche, Universita degli Studi dellAquila, Coppito, 67100 L'Aquila, Italy.
We present a comprehensive theoretical study, using state-of-the-art density functional theory simulations, of the structural and electrochemical properties of amorphous pristine and iron-doped nickel-(oxy)hydroxide catalyst films for water oxidation in alkaline solutions, referred to as NiCat and Fe:NiCat. Our simulations accurately capture the structural changes in locally ordered units, as reported by X-ray absorption spectroscopy, when the catalyst films are activated by exposure to a positive potential. We emphasize the critical role of proton-coupled electron transfer in the reversible oxidation of Ni(II) to Ni(III/IV) during this activation.
View Article and Find Full Text PDFJ Mol Model
January 2025
State Key Laboratory of Polyolefins and Catalysis, Shanghai, 200062, People's Republic of China.
Context: This study aims to reveal the reaction mechanisms of H and O on the NiO(100) and Ce-doped NiO(100) surfaces using the density functional theory (DFT) combined with the on-site Coulomb correction (DFT + U) method. It was found that H and O react favorably on the reduced surfaces of both materials. However, after the oxygen vacancy is filled, the activation energy for the reaction between H₂ and lattice oxygen increases.
View Article and Find Full Text PDFChemphyschem
January 2025
University of Namur, Department of Chemistry, Rue de Bruxelles, 61, 5000, Namur, BELGIUM.
The [4+2] Diels-Alder cycloaddition reaction between 2,5-DMF (1) and ethylene derivatives (2a-h) activated by electron-withdrawing groups has been studied at the density functional theory levels using a panoply of tools to unravel the reaction mechanisms. From the analysis of the reactivity indices, 2a-h behave as electrophiles while 1 as nucleophile, and the activation of the double bond of ethylene increases its electrophilicity, which is accompanied by an enhancement of the polarity of the reaction. The activation Gibbs free energy decreases linearly as a function of this increase of polarity, as estimated by the electrophilicity difference between the reactants.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!