Density-functional theory (DFT) is used to obtain the molecular data essential for predicting the reaction kinetics of chemical-ionization-mass spectrometry (CI-MS), as applied in the analysis of volatile organic compounds (VOCs). We study charge-transfer reactions from NO and O reagent ions to VOCs related to cork-taint and off-flavor in wine. We evaluate the collision rate coefficients of ion-molecule reactions by means of collision-based models. Many NO and O reactions are known to proceed at or close to their respective collision rates. Factors affecting the collision reaction rates, including electric-dipole moment and polarizability, temperature, and electric field are addressed, targeting the conditions of standard CI-MS techniques. The molecular electric-dipole moment and polarizability are the basic ingredients for the calculation of collision reaction rates in ion-molecule collision-based models. Using quantum-mechanical calculations, we evaluate these quantities for the neutral VOCs. We also investigate the thermodynamic feasibility of the reactions by computing the enthalpy change in these charge-transfer reactions.
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http://dx.doi.org/10.1021/jasms.1c00253 | DOI Listing |
ACS Cent Sci
January 2025
Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, China.
Herein, we report a visible-light-induced charge-transfer-complex-enabled dicarboxylation and deuterocarboxylation of C=C bonds with oxalate as a masked CO source under catalyst-free conditions. In this reaction, we disclosed the first example that the tetrabutylammonium oxalate could be able to aggregate with aryl substrates via π-cation interactions to form the charge transfer complexes, which subsequently triggers the single electron transfer from the oxalic dianion to the ammonium countercation under irradiation of 450 nm bule LEDs, releasing CO and CO radical anions. Diverse alkenes, dienes, trienes, and indoles, including challenging trisubstituted olefins, underwent dicarboxylation and anti-Markovnikov deuterocarboxylation with high selectivity to access valuable 1,2- and 1,4-dicarboxylic acids as well as indoline-derived diacids and β-deuterocarboxylic acids under mild conditions.
View Article and Find Full Text PDFNanoscale
January 2025
College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, China.
The sluggish kinetics of the hydrogen evolution reaction (HER) result in a high overpotential in alkaline solutions. A high-curvature metal oxide heterostructure can effectively boost the electrocatalytic HER by leveraging the tip-enhanced local electric field effect. Herein, NiP/NiMoO nanocones were synthesised on a nickel foam (NF) substrate by etching a metal-organic framework template.
View Article and Find Full Text PDFSmall
January 2025
Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, P. R. China.
Near-infrared light response catalysts have received great attention in renewable solar energy conversion, energy production, and environmental purification. Here, near-infrared photodegradation is successfully achieved in rare earth single atom anchored NaYF@g-CN heterojunctions by the synergistic effect of Z-scheme heterojunction and antenna of rare earth single atoms. The UV-vis light emitted by Tm can not only be directly absorbed by g-CN to generate electron-hole pairs, realizing efficient energy transfer, but also be absorbed by NaYF substrate, and generating photo-generated electrons at its impurity level, transferring the active charge to the valence band of g-CN, forming a Z-scheme heterojunction and further improving the photocatalytic efficiency.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemistry, Christ University, Bangalore 560029, Karnataka.
The inclusion of redox mediators into electrocatalytic systems facilitates rapid electron shuttling kinetics and boosts the overall catalytic performance of the electrode. This approach overcomes the sluggish reaction dynamics associated with direct electron transfer, which may be impeded by restricted analyte access to the electrode's active sites. In contrast to conventional synthetic redox mediators, naturally sourced phytomolecule rutin trihydrate (RT), extracted from apple juice, offers potential ecological advantages.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Shanghai Jiao Tong University, Frontiers Science Center for Transformative Molecules, CHINA.
A photoelectrocatalytic method is presented that achieves direct decarboxylative C(sp3)-P coupling, providing a modular route to alkylphosphinates and alkylphosphonates from readily available carboxylic acids. The success of this reaction hinges on the synergistic combination of electrochemical anodic oxidation and photocatalytic ligand to metal charge transfer (LMCT) decarboxylation. By employing P(III) reagents as limiting reagents, our approach enables efficient alkyl modification of medicinally important nucleosides and complex molecules derived phosphonites, which were challenging to access by existing methods.
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