Article
Environmental Sciences
Long Chen, Yu Huang, Yonggang Xue, Zhihui Jia, Wenliang Wang
Summary: This study investigates the influence of Criegee chemistry on the formation and growth processes as well as chemical compositions of secondary organic aerosol (SOA) through quantum chemical and kinetics modeling methods. The results reveal that the addition reactions of stabilized Criegee intermediates (SCIs) with hydroperoxide esters proceed through successive insertion of SCIs to form oligomers. The barrier heights and exothermicity of the oligomerization reactions are found to be dependent on the number of methyl substituents. Additionally, the rate coefficients of the reactions between SCIs and hydroperoxymethyl formate (HPMF) are influenced by the position of the methyl substituent.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Chemistry, Physical
Lei Yang, Mixtli Campos-Pineda, Katia Hatem, Jingsong Zhang
Summary: The yields of stabilized Criegee intermediates generated from the ozonolysis of propene were measured using CRDS and chemical titration methods. The results showed that both the total sCI and the stabilized CH2OO yields decreased with decreasing pressure. The nascent yields of the total sCIs, stabilized CH2OO, and stabilized CH3CHOO were determined to be 25+/- 2%, 20-25%, and 0-5% respectively. The branching ratios of the stabilized and high-energy CH2OO* and CH3CHOO* were also determined.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Lei Yang, Mixtli Campos-Pineda, Katia Hatem, Jingsong Zhang
Summary: In this study, the yields of stabilized Criegee intermediates produced from the ozonolysis of propene at low pressures were measured indirectly using CRDS and chemical titration methods. The results showed that the overall yields decreased with decreasing pressure, with the nascent yields ranging from 25% to 0-5%.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Michael Muzika, Nadav Genossar-Dan, Dana Fux, Shani Har Lavan, Uri Zamir, Illya Rozenberg, Patrick Hemberger, Joshua H. Baraban
Summary: Acrolein is a common pollutant that poses health concerns, but its generation processes are still not well understood. This study investigates the decomposition of acrolein at high temperatures and identifies reactive species produced during the early stages of the reaction.
ENVIRONMENTAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Analytical
Jing He, Hong Zhang, Yaqi Liu, Yun Ju, Yuwei He, Yanxiao Jiang, Jie Jiang
Summary: In this study, interfacial extraction and sonic spray ionization mass spectrometry were used to investigate the oxidation reaction of POPG mediated by ozone. The formation of Criegee intermediates (CIs) was observed for the first time, which sheds light on their significance in cell membrane peroxidation and provides insights into disease development associated with cell oxidative stress mediated by CIs.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Analytical
Jing He, Hong Zhang, Yaqi Liu, Yun Ju, Yanxiao Jiang, Jie Jiang
Summary: Criegee intermediates (CIs) were identified and characterized during the oxidation reaction of POPG mediated by ozone near the surface of a water droplet. Varying the water content provided evidence for the formation of CIs. Capture experiments using DMPO confirmed the selective characterization of CIs, and theoretical calculations suggested that surface ozonolysis of POPG was mainly mediated by anti-CI. These findings provide a new approach for identifying aqueous surface reactive species and contribute to understanding the development of diseases associated with cell oxidative stress mediated by CIs.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Luke Lewis-Borrell, Mahima Sneha, Ian P. Clark, Valerio Fasano, Adam Noble, Varinder K. Aggarwal, Andrew J. Orr-Ewing
Summary: Radical-induced 1,2-metalate rearrangements of boronate complexes are a promising class of reactions, and recent research indicates that iodine atom transfer (IAT) is the preferred pathway in these reactions.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Pei-Ling Luo, I-Yun Chen, M. Anwar H. Khan, Dudley E. Shallcross
Summary: The authors investigated the reaction mechanisms between the primary products of isoprene ozonolysis, formaldehyde oxide and formaldehyde, and evaluated their atmospheric implications using a global chemistry-transport model. The reaction kinetics and product yields were studied using time-resolved infrared laser spectrometry. The results showed temperature dependence of the reaction rate and provided insights into the formation of formic acid (HCOOH).
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Physical
Callum Robinson, Lavinia Onel, James Newman, Rachel Lade, Kendrew Au, Leonid Sheps, Dwayne E. Heard, Paul W. Seakins, Mark A. Blitz, Daniel Stone
Summary: The kinetics of the decomposition of the stabilized Criegee intermediate syn-CH3CHOO was investigated, and it was found that the reaction has a strong tunneling component under atmospheric conditions. Simulations were also conducted for the unimolecular isomerization of the stabilized Criegee intermediate antiCH(3)CHOO.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Environmental Sciences
Yuanyuan Wei, Qingzhu Zhang, Xinxi Huo, Wenxing Wang, Qiao Wang
Summary: Criegee intermediates (CIs) play a crucial role in the formation of secondary organic aerosols, and their reactions with formamide are similar to those with formic acid. The formation of hydroperoxymethyl formimidate (P4) is the most favorable pathway for both gas-phase and air/water interface reactions. The product (P4) can participate in new particle formation (NPF), and water molecules enhance NPF.
Article
Chemistry, Physical
Zih-Syuan Su, Yuan-Pern Lee
Summary: The rapid reactions between Criegee intermediates and hydrogen halides have significant impacts on atmospheric chemistry, especially in polluted urban atmospheres. Using an advanced spectrometer, researchers observed and identified the infrared absorption spectra of transient species and end products in the reaction of CH3CHOO + HCl. They found that the formation of anticonformer of chloroethyl hydroperoxide (anti-CEHP or anti-CH3CHClOOH) is more important than the formation of acetyl chloride (CH3C(O)Cl). Additionally, they determined the overall rate coefficient of the reaction, indicating that anti-CH3CHOO reacts with HCl much faster than syn-CH3CHOO.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Environmental Sciences
Xiaoxiao Lin, Xiaofeng Tang, Zuoying Wen, Bo Long, Christa Fittschen, Xuejun Gu, Yanbo Gai, Weijun Zhang
Summary: The oxidation of 1,3,5-trimethylbenzene (1,3,5-TMB) initiated by OH under NOx-free conditions was studied using experimental and theoretical methods. The presence of high mass O-2-bridged bicyclic compounds in the particle phase was observed and confirmed. Theoretical calculations shed light on the mechanism of formation of these bicyclic compounds.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Chemistry, Multidisciplinary
Nadav Genossar-Dan, Sharona Atlas, Dana Fux, Shani Har Lavan, Uri Zamir, Illya Rozenberg, Thanh Lam Nguyen, Patrick Hemberger, Joshua H. Baraban
Summary: We report the first direct detection of ethyl radical in the pyrolysis of ethane. This was achieved through the use of a microreactor coupled with synchrotron radiation and photoelectron photoion coincidence (PEPICO) spectroscopy. Our measurements, along with computational fluid dynamics simulations, provide insights into the formation mechanism of ethyl radicals and highlight the importance of bimolecular reactions in this process.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Lei Li, Qingzhu Zhang, Yuanyuan Wei, Qiao Wang, Wenxing Wang
Summary: In this study, the energy barriers for the reactions of CH3CHOO with MGA were calculated using the density functional theory (DFT) method. The results showed that the reactions involving the COOH group of MGA were minimally affected, while hydrogen bonding had an impact on the reactions involving alpha-OH and beta-OH groups. Water molecule acted as a catalyst to decrease the energy barriers of these reactions. The simulations also indicated that the reaction of CH3CHOO with the COOH group was the main pathway in the atmosphere, and the reaction products could form clusters to participate in particle formation.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Chemistry, Physical
Shi-Chao Ren, Wen-Xin Lv, Xing Yang, Jia-Lei Yan, Jun Xu, Fang-Xin Wang, Lin Hao, Huifang Chai, Zhichao Jin, Yonggui Robin Chi
Summary: A carbene-catalyzed reductive coupling reaction of carboxylic esters and substituted Hantzsch esters has been disclosed, which is promoted by visible light irradiation and allows for incorporation of sophisticated structures, including those found in medicines, into ketone molecules under mild conditions.
Article
Thermodynamics
Stephen J. Klippenstein, Peter Glarborg
Summary: Recent modeling studies of NH3 oxidation show significant discrepancies, with high-level theoretical kinetics predictions for the NH2 + HO2 reaction deviating significantly from values used in most previous modeling studies.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Stephen J. Klippenstein, Raghu Sivaramakrishnan, Ultan Burke, Kieran P. Somers, Henry J. Curran, Liming Cai, Heinz Pitsch, Matteo Pelucchi, Tiziano Faravelli, Peter Glarborg
Summary: The H O center dot 2 + H O center dot 2 reaction is important in combustion under low temperatures and high pressures. Previous theoretical and experimental studies have shown discrepancies. This study uses high-level electronic structure theory, sophisticated transition state theory, and master equation analyses to predict the thermal kinetics on the H2O4 surface and discovers a new reaction channel.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Luna Pratali Maffei, Kevin B. Moore III, Yuri Georgievskii, Clayton R. Mulvihill, Sarah N. Elliott, Jaeyoung Cho, Raghu Sivaramakrishnan, Tiziano Faravelli, Stephen J. Klippenstein
Summary: This study presents an automated methodology for calculating the prompt effects of a specific species in a kinetic mechanism, including reaction selection, theoretical calculation of rate constants and prompt branching fractions, and final rate constant fitting. The methodology is validated using literature data and employs a microcanonical statistical model for estimating the energy partition between hot fragments. The results demonstrate the significant impact of prompt dissociation on high-temperature combustion reactivity.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Manik Kumer Ghosh, Snehasish Panigrahy, Shijun Dong, Sarah N. Elliott, Stephen J. Klippenstein, Henry J. Curran
Summary: The influence of thermochemistry on the reactivity of fuels at low temperatures is investigated by comparing different sets of thermochemistry and their impact on chemical model predictions. Experimental ignition delay times are simulated using NUIGMech1.2 and different thermochemistry sets, showing that the thermochemistry of species involved in the low-temperature reaction sequence significantly affects fuel reactivity.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Ziyu Wang, Hao Zhao, Chao Yan, Ying Lin, Aditya D. Lele, Wenbin Xu, Brandon Rotavera, Ahren W. Jasper, Stephen J. Klippenstein, Yiguang Ju
Summary: Methanol oxidation was studied in a supercritical pressure jet-stirred reactor. It was found that the onset temperature of methanol oxidation at 100 atm is lower than that at 10 atm and a negative temperature coefficient (NTC) behavior was observed at fuel-rich conditions. The kinetics models failed to predict these trends accurately. By updating elementary reaction rates and adding new reaction pathways, the model improved but discrepancies still exist.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Jaeyoung Cho, Yujie Tao, Yuri Georgievskii, Stephen J. Klippenstein, Ahren W. Jasper, Raghu Sivaramakrishnan
Summary: Collisional energy transfer is crucial for a-priori calculations of pressure-dependent rate constants. However, accurate determinations of energy transfer parameters are rare, so most studies rely on fitting these parameters to experimental measurements or estimates from literature. This study quantifies the impact of uncertainty in energy transfer parameters on the dissociation kinetics of 1-methyl allyl (1MA) radical, relevant to the combustion of butene isomers. Simulation and theoretical calculations were performed to assess the effect of uncertainties on flame propagation and reaction kinetics.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Long Zhu, Snehasish Panigrahy, Sarah N. Elliott, Stephen J. Klippenstein, Mohammadreza Baigmohammadi, A. Abd El-Sabor Mohamed, Joshua W. Hargis, Sulaiman Alturaifi, Olivier Mathieu, Eric L. Petersen, Karl Alexander Heufer, Ajoy Ramalingam, Zhandong Wang, Henry J. Curran
Summary: This work presents an experimental and kinetic modeling study of propane oxidation. Ignition delay times of propane, as well as CO and H2O mole fraction profiles for propane oxidation, were measured in different experimental setups. The obtained experimental data were used to update the kinetic mechanisms for propane oxidation, resulting in improved model agreement with the experimental results. (Rating: 8 points)
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Manik Kumer Ghosh, Sarah N. Elliott, Kieran P. Somers, Stephen J. Klippenstein, Henry J. Curran
Summary: A set of group additivity values (GAV) for calculating the heat of formation is derived from an extensive and accurate database of ab initio heats of formation. These GAVs significantly improve the accuracy of estimating the heats of formation for combustion relevant hydrocarbons and oxygenated hydrocarbons, and are critical for the development of accurate chemical kinetic models.
COMBUSTION AND FLAME
(2023)
Article
Thermodynamics
Jaeyoung Cho, Ahren W. Jasper, Yuri Georgievskii, Stephen J. Klippenstein, Raghu Sivaramakrishnan
Summary: This study analyzes the kinetics of resonantly stabilized radicals, focusing on the dissociation and reactions of different allylic radicals. The results show the significance of energy transfer in these reactions, using potential energy surface calculations and kinetic simulations.
COMBUSTION AND FLAME
(2023)
Article
Chemistry, Physical
Sarah N. Elliott, Murat Keceli, Manik K. Ghosh, Kieran P. Somers, Henry J. Curran, Stephen J. Klippenstein
Summary: The CBH-ANL approach is used to predict the heat of formation for 194 alkane oxidation species with high accuracy. The method can produce delta H-f(0 K) values with 2 sigma uncertainties of 0.2-0.5 kcal mol(-1). The approach involves constructing balanced chemical equations and refining reference delta H-f(0 K) values for large reference species using a laddering approach.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Physics, Multidisciplinary
Yuki Kobayashi, Christian Heide, Amalya C. Johnson, Vishal Tiwari, Fang Liu, David A. Reis, Tony F. Heinz, Shambhu Ghimire
Summary: Interactions between quantum materials and strong laser fields can result in non-equilibrium electronic states. Monolayer transition metal dichalcogenides, as direct-gap semiconductors with quantum confinement, offer opportunities for controlling excitons. However, characterizing strong-field driven exciton dynamics has been challenging.
Article
Chemistry, Multidisciplinary
Fang Liu
Summary: Time- and angle-resolved photoemission spectroscopy (TR-ARPES) is a direct method that allows for probing charge carrier dynamics with momentum resolution, which is crucial for understanding the fundamental physics and applications of 2D materials. Recent developments in table-top pulsed extreme UV (EUV) sources based on high harmonic generation have addressed the challenges of probing high crystal momenta in 2D monolayers and have enabled direct imaging of photoelectrons with superior time, energy, and crystal momentum resolution. This has provided unprecedented opportunities to reveal the intrinsic dynamics of 2D materials.
Article
Optics
B. Ardini, A. BAssI, A. Candeo, A. Genco, C. Trovatello, F. Liu, X. Zhu, G. Valentini, G. Cerullo, R. Vanna, C. Manzoni
Summary: Raman microscopy is a powerful technique for mapping the chemical composition of a sample. This paper presents a compact wide-field Raman microscope based on a time-domain Fourier-transform approach, allowing for parallel acquisition of Raman spectra on all pixels of a 2D detector. The system has high spatial and spectral resolutions and the ability to separate fluorescence and Raman signals.
Article
Optics
Qitong Li, Jung-Hwan Song, Fenghao Xu, Jorik van de Groep, Jiho Hong, Alwin Daus, Yan Joe Lee, Amalya C. Johnson, Eric Pop, Fang Liu, Mark L. Brongersma
Summary: A general pathway to reduce the detrimental impact of dephasing and non-radiative decay processes in quantum devices is illustrated through photonic design of device electrodes. The design enables large Purcell enhancement, convenient electrical gating, and high modulation efficiencies.
Article
Chemistry, Physical
Trisha Bhagde, Anne S. Hansen, Shuguang Chen, Patrick J. Walsh, Stephen J. Klippenstein, Marsha Lester
Summary: This study investigates the structure, stability, and dissociation dynamics of hydroperoxyalkyl radicals through experimental and theoretical methods. The IR spectroscopic features of QOOD radicals near the transition state barrier are observed, and the overtone OD stretch vibration is identified using spectroscopy techniques. The experimental results are in agreement with the theoretical calculations, confirming the enhancement of unimolecular decay by heavy-atom tunneling in the dissociation process of radicals.
FARADAY DISCUSSIONS
(2022)