Skeletal rearrangement of a series of substituted Dewar benzenes to biaryl products was studied with DFT methods. Excellent agreement of calculated free energies of activation with experimental kinetic data was achieved. Two different transition states were proposed to be involved in the rearrangement. The reaction path was studied both by static intrinsic reaction coordinate (IRC) calculations and first-principles Car-Parrinello and Born-Oppenheimer molecular dynamics. All approaches confirmed the suggested reaction mechanism.
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http://dx.doi.org/10.1021/jo902065n | DOI Listing |
J Mol Graph Model
January 2025
"VINČA" Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, 11001, Belgrade, Serbia.
Technetium-99m plays a pivotal role in nuclear medicine, offering unique IMAGING capabilities due to its favorable physical and chemical properties. This study investigates the redox behavior and electronic structures of three representative Tc(V) oxo complexes, [TcO(HMPAO)], [TcO(Bicisate)], and [TcO(DMSA)], using computational techniques. Employing relativistic density functional theory with the Zero-Order Regular Approximation (ZORA), we analyze singlet-triplet energy gaps, Gibbs free energy changes, and redox potentials in neutral and acidic environments.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Department of Chemistry, St. Petersburg University, Universitetskaya nab., 7/9, Saint Petersburg 199034, Russia.
This study investigates the electrochemical degradation mechanisms of nickel-salen (NiSalen) polymers, with a focus on improving the material's stability in supercapacitor applications. We analyzed the effects of steric hindrance near the nickel center by incorporating different bulky substituents into NiSalen complexes, aiming to mitigate water-induced degradation. Electrochemical performance was assessed using cyclic voltammetry, operando conductance, and impedance measurements, while X-ray photoelectron spectroscopy (XPS) provided insights into molecular degradation pathways.
View Article and Find Full Text PDFPharmaceuticals (Basel)
January 2025
Laboratory of Organic Chemistry, Department of Chemistry, National and Kapodistrian University of Athens, Panepistimioupolis Zografou, 11571 Athens, Greece.
Background: In this study, two chalcone analogs were synthesized through in silico and experimental methods, and their potential to inhibit the lipoxygenase enzyme, which plays a role in the inflammation pathway, was assessed. Specifically, this study is a continuation of previous research in which chalcone derivatives were synthesized and characterized.
Objectives/methods: In the current work, we present the re-synthesis of two chalcones, with a focus on their docking studies, NMR analysis, and dynamic simulations.
Molecules
January 2025
Centro de Investigação em Química (CIQUP), Institute of Molecular Sciences (IMS), Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal.
An extensive thermochemical study of γ-undecanolactone and δ-undecanolactone has been developed using two complementary calorimetric techniques. The combustion energy of each compound was determined by static-bomb combustion calorimetry, and the corresponding enthalpy of vaporization was determined by high-temperature Calvet microcalorimetry, in which both properties of each compound are reported at = 298.15 K.
View Article and Find Full Text PDFMolecules
January 2025
College of Science, Liaoning Petrochemical University, Fushun 113001, China.
The electronic structure characteristics of bilayer graphyne, bilayer graphdiyne, and bilayer graphtriyne were systematically studied using molecular orbital (MO) analysis, density of states (DOS), and interaction region indicator (IRI) methods. The delocalization characteristics of the out-of-plane and in-plane π electrons (i.e.
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