The gas-phase reaction between -2-methyl-2-butenal and chlorine (Cl) atoms has been studied in a simulation chamber at 298 ± 2 K and 760 ± 5 Torr of air under free-NO conditions. The rate coefficient of this reaction was determined as = (2.45 ± 0.32) × 10- cm molecule s by using a relative method and Fourier transform infrared spectroscopy. In addition to this technique, gas chromatography coupled to mass spectrometry and proton transfer time-of-flight mass spectrometry were used to detect and monitor the time evolution of the gas-phase reaction products. The major primary reaction product from the addition of Cl to the C-3 of -2-methyl-2-butenal was 3-chloro-2-butanone, with a molar yield (Y) of (52.5 ± 7.3)%. Acetaldehyde (Y = (40.8 ± 0.6)%) and HCl were also identified, indicating that the H-abstraction by Cl from the aldehyde group is a reaction pathway as well. Secondary organic aerosol (SOA) formation was investigated by using a fast mobility particle sizer spectrometer. The SOA yield in the Cl + -2-methyl-2-butenal reaction is reported to be lower than 2.4%, thus its impact can be considered negligible. The atmospheric importance of the titled reaction is similar to the corresponding OH reaction in areas with high Cl concentration.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7116312 | PMC |
http://dx.doi.org/10.3390/atmos11070715 | DOI Listing |
Sci Rep
January 2025
Department of Chemistry, Federal University of Paraná, Curitiba, 81531-980, Brazil.
Gold-based (Au) nanostructures are efficient catalysts for CO oxidation, hydrogen evolution (HER), and oxygen evolution (OER) reactions, but stabilizing them on graphene (Gr) is challenging due to weak affinity from delocalized [Formula: see text] carbon orbitals. This study investigates forming metal alloys to enhance stability and catalytic performance of Au-based nanocatalysts. Using ab initio density functional theory, we characterize [Formula: see text] sub-nanoclusters (M = Ni, Pd, Pt, Cu, and Ag) with atomicities [Formula: see text], both in gas-phase and supported on Gr.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
ConspectusReactions of gas phase molecules with surfaces play key roles in atmospheric and environmental chemistry. Reactive uptake coefficients (γ), the fraction of gas-surface collisions that yield a reaction, are used to quantify the kinetics in these heterogeneous and multiphase systems. Unlike rate coefficients for homogeneous gas- or liquid-phase reactions, uptake coefficients are system- and observation-dependent quantities that depend upon a multitude of underlying elementary steps.
View Article and Find Full Text PDFJ Mol Model
January 2025
Departamento de Investigación y Desarrollo, ConsultoresAcademicos SpA, Moneda 1137, 8340457, Santiago, Chile.
Context: This study meticulously examines the criteria for assigning electron rearrangements along the intrinsic reaction coordinate (IRC) leading to bond formation and breaking processes during the pyrolytic isomerization of cubane (CUB) to 1,3,5,7-cyclooctatetraene (COT) from both thermochemical and bonding perspectives. Notably, no cusp-type function was detected in the initial thermal conversion step of CUB to bicyclo[4.2.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, A-6020 Innsbruck, Austria.
Peptide bond formation from the pure protonated glycine dimer, H(Gly), and from the mixed protonated glycine-diglycine dimer, HGly(Gly), was recently found experimentally to occur in gas-phase experiments in the absence of any catalyst and especially under anhydrous conditions [, 2023, , 775]. In this contribution we further examine the conditions of such unimolecular reactions by means of density-functional theory calculations at the DFT/M06 2X/6-311G++(2df,p) level, focusing in particular on the role played by the protonation site. Two pathways, stepwise and concerted, are identified for the pure protonated dimer, and six pathways are examined for the mixed dimer.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
Within the framework of surface-adsorbate interactions relevant to chemical reactions of spent nuclear fuel, the study of actinide oxide systems remains one of the most challenging tasks at both the experimental and computational levels. Consequently, our understanding of the effect of their unique electronic configurations on surface reactions lags behind that of d-block oxides. To investigate the surface properties of this system, we present the first infrared spectroscopy analysis of carbon monoxide (CO) interaction with a monocrystalline actinide oxide, UO(111).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!