1
|
Kharazmi A, Harrison AW, Shaw MF, Jordan MJT, Kable SH. The Effect of β-Hydrogens on the Tropospheric Photochemistry of Aldehydes: Norrish Type 1, Triple Fragmentation, and Methylketene Formation from Propanal. J Am Chem Soc 2024; 146:21308-21319. [PMID: 39073403 DOI: 10.1021/jacs.4c00877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Wavelength and pressure dependent quantum yields (ϕ, QYs) of propanal photolysis have been measured for photolysis wavelengths, λ = 300-330 nm, and buffer gases of 3-10 Torr propanal and 0-757 Torr N2. Following laser photolysis, three photochemical pathways were established, using Fourier transform infrared spectroscopy of the stable end-products. Photolysis is dominated by the Norrish Type 1 reaction, which has been reported previously, but with inconsistent quantum yields. The propanal α-hydrogen leads to a 4-center elimination of H2, as observed in CH3CHO, here leading to methylketene. The presence of hydrogen attached to the β-carbon allows a new photochemical pathway: concerted triple fragmentation into CO + H2 + C2H4 via a 5-center transition state. Neither of these channels has been reported previously. No evidence for the previously reported C2H6 + CO, C2H4 + H2CO or CH3 + CH2CHO channels, nor for phototautomerization to 1-propenol (CH3CH═CHOH) was found. Modeling of the wavelength, pressure and collision partner dependence of the QYs allows us to reconcile the previous NT1a results and make recommendations for the quantum yields of all three channels under tropospheric conditions. The general impact of β-hydrogen atoms in the photochemistry of aldehydes is to open up new pathways from cyclic transition states and to reduce the importance of other photolysis or isomerization channels.
Collapse
Affiliation(s)
- Alireza Kharazmi
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Aaron W Harrison
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Miranda F Shaw
- School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Meredith J T Jordan
- School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia
| | - Scott H Kable
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| |
Collapse
|
2
|
Sun C, Xu B, Zeng Y. Pressure and temperature dependent kinetics and the reaction mechanism of Criegee intermediates with vinyl alcohol: a theoretical study. Phys Chem Chem Phys 2024; 26:9524-9533. [PMID: 38451236 DOI: 10.1039/d3cp06115a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Criegee intermediates (CIs), the key intermediates in the ozonolysis of olefins in atmosphere, have received much attention due to their high activity. The reaction mechanism of the most simple Criegee intermediate CH2OO with vinyl alcohol (VA) was investigated by using the HL//M06-2X/def2TZVP method. The temperature and pressure dependent rate constant and product branching ratio were calculated using the master equation method. For CH2OO + syn-VA, 1,4-insertion is the main reaction channel while for the CH2OO + anti-VA, cycloaddition and 1,2-insertion into the O-H bond are more favorable than the 1,4-insertion reaction. The 1,4-insertion or cycloaddition intermediates are stabilized collisionally at 300 K and 760 torr, and the dissociation products involving OH are formed at higher temperature and lower pressure. The rate constants of the CH2OO reaction with syn-VA and anti-VA both show negative temperature effects, and they are 2.95 × 10-11 and 2.07 × 10-13 cm3 molecule-1 s-1 at 300 K, respectively, and the former is agreement with the prediction in the literature.
Collapse
Affiliation(s)
- Cuihong Sun
- Shijiazhuang Key Laboratory of Low Carbon Energy Materials, Technology Innovation Center of HeBei for Heterocyclic Compound, College of Chemical Engineering, Shijiazhuang University, Shijiazhuang 050035, P. R. China
| | - Baoen Xu
- Shijiazhuang Key Laboratory of Low Carbon Energy Materials, Technology Innovation Center of HeBei for Heterocyclic Compound, College of Chemical Engineering, Shijiazhuang University, Shijiazhuang 050035, P. R. China
| | - Yanli Zeng
- College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, P.R. China.
| |
Collapse
|
3
|
Welsh BA, Corrigan ME, Assaf E, Nauta K, Sebastianelli P, Jordan MJT, Fittschen C, Kable SH. Photophysical oxidation of HCHO produces HO 2 radicals. Nat Chem 2023; 15:1350-1357. [PMID: 37414879 DOI: 10.1038/s41557-023-01272-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/07/2023] [Indexed: 07/08/2023]
Abstract
Formaldehyde, HCHO, is the highest-volume carbonyl in the atmosphere. It absorbs sunlight at wavelengths shorter than 330 nm and photolyses to form H and HCO radicals, which then react with O2 to form HO2. Here we show HCHO has an additional HO2 formation pathway. At photolysis energies below the energetic threshold for radical formation we directly detect HO2 at low pressures by cavity ring-down spectroscopy and indirectly detect HO2 at 1 bar by Fourier-transform infrared spectroscopy end-product analysis. Supported by electronic structure theory and master equation simulations, we attribute this HO2 to photophysical oxidation (PPO): photoexcited HCHO relaxes non-radiatively to the ground electronic state where the far-from-equilibrium, vibrationally activated HCHO molecules react with thermal O2. PPO is likely to be a general mechanism in tropospheric chemistry and, unlike photolysis, PPO will increase with increasing O2 pressure.
Collapse
Affiliation(s)
- Blair A Welsh
- School of Chemistry, University of New South Wales, Kensington, New South Wales, Australia
- Combustion Research Facility, Sandia National Laboratories, Livermore, CA, USA
| | - Maggie E Corrigan
- School of Chemistry, University of Sydney, Sydney, New South Wales, Australia
| | - Emmanuel Assaf
- Université Lille, CNRS, UMR 8522, PC2A-Physicochimie des Processus de Combustion et de l'Atmosphère, Lille, France
- Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Klaas Nauta
- School of Chemistry, University of New South Wales, Kensington, New South Wales, Australia
| | - Paolo Sebastianelli
- School of Chemistry, University of New South Wales, Kensington, New South Wales, Australia
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Meredith J T Jordan
- School of Chemistry, University of Sydney, Sydney, New South Wales, Australia.
| | - Christa Fittschen
- Université Lille, CNRS, UMR 8522, PC2A-Physicochimie des Processus de Combustion et de l'Atmosphère, Lille, France
| | - Scott H Kable
- School of Chemistry, University of New South Wales, Kensington, New South Wales, Australia.
| |
Collapse
|
4
|
Deal AM, Vaida V. Oxygen Effect on the Ultraviolet-C Photochemistry of Lactic Acid. J Phys Chem A 2023; 127:2936-2945. [PMID: 36962071 DOI: 10.1021/acs.jpca.3c00992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
Lactic acid, a small α-hydroxyacid, is ubiquitous in both indoor and outdoor environments. Recently, the photochemistry of lactic acid has garnered interest among the abiotic organic chemistry community as it would have been present in abiotic settings and photoactive with the high-energy solar radiation that would have been available in the low oxygen early Earth environment. Additionally, we propose that the photochemistry of lactic acid is relevant to modern Earth during indoor ultraviolet-C (UVC) sterilization procedures as lactic acid is emitted by humans and is thus prevalent in indoor environments where UVC sterilization is increasingly being used. Here, we study the oxygen effect on the gas phase photolysis of lactic acid using Fourier-transform infrared (FTIR) spectroscopy and isotopically labeled oxygen (18O2). We find that the major products of gas phase lactic acid photolysis are CO2, CO, acetaldehyde, and acetic acid. Furthermore, these products are the same with or without added oxygen, but the partial pressures of produced CO2, CO, and acetaldehyde increase with the amount of added oxygen. Notably, the added oxygen is primarily incorporated into produced CO2 and CO, while little or none is incorporated into acetaldehyde. We combine the results presented here with those in the literature to propose a mechanism for the gas phase photolysis of lactic acid and the role of oxygen in this mechanism. Finally, we compare the output of a krypton-chloride excimer lamp (λ = 222 nm), one of the lamps proposed for UVC sterilization procedures, to the absorption of lactic acid. We show that lactic acid would be photoactive during UVC sterilization procedures, and we use the gas phase results presented here and aqueous lactic acid photolysis results previously published to assess potential byproducts from lactic acid reactions during UVC sterilization procedures.
Collapse
Affiliation(s)
- Alexandra M Deal
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
| | - Veronica Vaida
- Department of Chemistry, University of Colorado Boulder, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado 80309, United States
| |
Collapse
|
5
|
Randi PAS, Pastega DF, Bettega MHF, Jones NC, Hoffmann SV, Eden S, Souza Barbosa A, Limão-Vieira P. Electronically excited states of formic acid investigated by theoretical and experimental methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 289:122237. [PMID: 36535224 DOI: 10.1016/j.saa.2022.122237] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/07/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
Absolute cross-section values are reported from high-resolution vacuum ultraviolet (VUV) photoabsorption measurements of gas-phase formic acid (HCOOH) in the photon energy range 4.7-10.8 eV (265-115 nm), together with quantum chemical calculations to provide vertical energies and oscillator strengths. The combination of experimental and theoretical methods has allowed a comprehensive assignment of the electronic transitions. The VUV spectrum reveals various vibronic features not previously reported in the literature, notably associated with (3pa'←10a'), (3p'a'←10a'), (3sa'←2a″) and (3pa'←2a″) Rydberg transitions. The assignment of vibrational features in the absorption bands reveal that the C=O stretching, v3'a', the H'-O-C' deformation, v5'a', the C-O stretching, v6'a', and the O=C-O' deformation, v7'a' modes are mainly active. The measured absolute photoabsorption cross sections have also been used to estimate the photolysis lifetime of HCOOH in the upper stratosphere (30-50 km), showing that solar photolysis is an important sink at altitudes above 30 km but not in the troposphere. Potential energy curves for the lowest-lying electronic excited states, as a function of the C=O coordinate, are obtained employing time dependent density functional theory (TD-DFT). These calculations have shown the relevance of internal conversion from Rydberg to valence character governing the nuclear dynamics, yielding clear evidence of the rather complex multidimensional nature of the potential energy surfaces involved.
Collapse
Affiliation(s)
- P A S Randi
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - D F Pastega
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - M H F Bettega
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - N C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000, Aarhus C, Denmark
| | - S V Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000, Aarhus C, Denmark
| | - S Eden
- School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
| | - A Souza Barbosa
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil.
| | - P Limão-Vieira
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil; Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
| |
Collapse
|
6
|
Pickering emulsions stabilized by hemp protein nanoparticles: Tuning the emulsion characteristics by adjusting anti-solvent precipitation. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.108434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
7
|
Catalytic effects on decomposition of formic acid in the atmosphere – A kinetic and thermochemical investigation. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
8
|
Meuwly M. Atomistic Simulations for Reactions and Vibrational Spectroscopy in the Era of Machine Learning─ Quo Vadis?. J Phys Chem B 2022; 126:2155-2167. [PMID: 35286087 DOI: 10.1021/acs.jpcb.2c00212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Atomistic simulations using accurate energy functions can provide molecular-level insight into functional motions of molecules in the gas and in the condensed phase. This Perspective delineates the present status of the field from the efforts of others and some of our own work and discusses open questions and future prospects. The combination of physics-based long-range representations using multipolar charge distributions and kernel representations for the bonded interactions is shown to provide realistic models for the exploration of the infrared spectroscopy of molecules in solution. For reactions, empirical models connecting dedicated energy functions for the reactant and product states allow statistically meaningful sampling of conformational space whereas machine-learned energy functions are superior in accuracy. The future combination of physics-based models with machine-learning techniques and integration into all-purpose molecular simulation software provides a unique opportunity to bring such dynamics simulations closer to reality.
Collapse
Affiliation(s)
- Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland
| |
Collapse
|
9
|
Savee J, Sztáray B, Hemberger P, Zádor J, Bodi A, Osborn DL. Unimolecular isomerisation of 1,5-hexadiyne observed by threshold photoelectron photoion coincidence spectroscopy. Faraday Discuss 2022; 238:645-664. [DOI: 10.1039/d2fd00028h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The unimolecular isomerisation of the prompt propargyl + propargyl "head-to-head" adduct, 1,5- hexadiyne, to fulvene and benzene by the 3,4-dimethylenecyclobut-1-ene (DMCB) intermediate (all C6H6) was studied in the high-pressure limit...
Collapse
|
10
|
Mishra D, Reino-González J, Obaid R, LaForge AC, Díaz-Tendero S, Martín F, Berrah N. Ultrafast molecular dynamics in ionized 1- and 2-propanol: from simple fragmentation to complex isomerization and roaming mechanisms. Phys Chem Chem Phys 2021; 24:433-443. [PMID: 34897321 DOI: 10.1039/d1cp04011a] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Upon photoexcitation, molecules can undergo numerous complex processes, such as isomerization and roaming, leading to changes in the molecular and electronic structure. Here, we report on the time-resolved ultrafast nuclear dynamics, initiated by laser ionization, in the two structural isomers, 1- and 2-propanol, using a combination of pump-probe spectroscopy and coincident Coulomb explosion imaging. Our measurements, paired with quantum chemistry calculations, identify the mechanisms for the observed two- and three-body dissociation channels for both isomers. In particular, the fragmentation channel of 2-propanol associated with the loss of CH3 shows possible evidence of methyl roaming. Moreover, the electronic structure of this roaming methyl fragment could be responsible for the enhanced ionization also observed for this channel. Finally, comparison with similar studies done on ethanol and acetonitrile helps establish a correlation between the length of the alkyl chain and the likelihood of hydrogen migration.
Collapse
Affiliation(s)
- Debadarshini Mishra
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| | - Juan Reino-González
- Departamento de Química, Universidad Autónoma de Madrid, Módulo 13, 28049 Madrid, EU, Spain
| | - Razib Obaid
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| | - Aaron C LaForge
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| | - Sergio Díaz-Tendero
- Departamento de Química, Universidad Autónoma de Madrid, Módulo 13, 28049 Madrid, EU, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, EU, Spain.,Institute for Advanced Research in Chemical Sciences(IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, EU, Spain
| | - Fernando Martín
- Departamento de Química, Universidad Autónoma de Madrid, Módulo 13, 28049 Madrid, EU, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, EU, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nano), Campus de Cantoblanco, 28049 Madrid, EU, Spain.,Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, EU, Spain
| | - Nora Berrah
- Department of Physics, University of Connecticut, Storrs, Connecticut, 06269, USA.
| |
Collapse
|
11
|
Sadiek I, Friedrichs G, Sakai Y. Ab Initio and RRKM/Master Equation Analysis of the Photolysis and Thermal Unimolecular Decomposition of Bromoacetaldehyde. J Phys Chem A 2021; 125:8282-8293. [PMID: 34498882 DOI: 10.1021/acs.jpca.1c04347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bromoacetaldehyde (BrCH2CHO) is a major stable brominated organic intermediate of the bromine-ethylene addition reaction during the arctic bromine explosion events. Similar to acetaldehyde, which has been recently identified as a source of organic acids in the troposphere, it may be subjected to photo-tautomerization initially forming brominated vinyl compounds. In this study, we investigate the unimolecular reactions of BrCH2CHO under both photolytic and thermal conditions using high-level quantum chemical calculations and Rice-Ramsperger-Kassel-Marcus (RRKM)/master equation analysis. The unimolecular decomposition of BrCH2CHO takes place through 14 dissociation and isomerization channels along a potential energy surface involving eight wells. Under the assumption of singlet ground-state potential energy surface-dominated photodynamics, the primary photodissociation yields of BrCH2CHO are investigated under both collision-free and collision energy transfer conditions. At atmospheric pressure and under tropospheric actinic flux conditions at ground level, depending on the assumed collisional energy transfer parameter, 150 cm-1 < ⟨ΔEdown⟩ < 450 cm-1, 78-33% of BrCH2CHO undergoes direct photodissociation instead of collisional deactivation at an excitation wavelength of 320 nm. This is significantly higher than the 14% reported for acetaldehyde, hence indicating a strong effect of bromine substitution on the product photolysis yield that is related to additional favorable Br and HBr forming dissociation channels. In contrast to the overall photodissociation quantum yield, the relative branching fractions of the photodissociation products are less dependent on the collisional energy transfer parameter. For a representative value of ⟨ΔEdown⟩ = 300 cm-1 and an excitation wavelength of 320 nm, with 27% for C-C bond fission, 11% for C-Br bond fission, 7% for HBr elimination, and only below 2% each for a consecutive O-Br fission reaction and the photo-tautomerization channel yielding brominated vinyl alcohol, the photodissociation is markedly different from the acetaldehyde case. Finally, as brominated halogenated compounds are of interest for flame inhibition purposes, thermal multichannel unimolecular rate constants were calculated for temperatures in the range from 500 to 2000 K. At a temperature of 2000 K and ambient pressure, the two main reaction channels are the C-Br and C-C bond fissions, contributing 35 and 43% to the total reaction flux, respectively.
Collapse
Affiliation(s)
- Ibrahim Sadiek
- Institute of Physical Chemistry, University of Kiel, 24118 Kiel, Germany.,Leibniz Institute for Plasma Science and Technology (INP), 17489 Greifswald, Germany
| | - Gernot Friedrichs
- Institute of Physical Chemistry, University of Kiel, 24118 Kiel, Germany.,KMS Kiel Marine Science-Centre for Interdisciplinary Marine Sciences, University of Kiel, 24118 Kiel, Germany
| | - Yasuyuki Sakai
- Department of Mechanical Systems Engineering, Ibaraki University, Hitachi 316-8511, Ibaraki, Japan
| |
Collapse
|
12
|
Singh SK, Vuppuluri V, Sun BJ, Chang BY, Eckhardt AK, Son SF, Chang AHH, Kaiser RI. Identification of Elusive Keto and Enol Intermediates in the Photolysis of 1,3,5-Trinitro-1,3,5-Triazinane. J Phys Chem Lett 2021; 12:6062-6069. [PMID: 34169725 DOI: 10.1021/acs.jpclett.1c01610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Enols have emerged as critical reactive intermediates in combustion processes and in fundamental molecular mass growth processes in the interstellar medium, but the elementary reaction pathways to enols in extreme environments, such as during the decomposition of molecular energetic materials, are still elusive. Here, we report on the original identification of the enol and keto isomers of oxy-s-triazine, as well as its deoxygenated derivative 1,3,5-triazine, formed in the photodecomposition processes of 1,3,5-trinitro-1,3,5-triazinane (RDX)-a molecular energetic material. The identification was facilitated by exploiting isomer-selective tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) in conjunction with quantum chemical calculations. The present study reports the first experimental evidence of an enol intermediate in the dissociation domain of a nitramine-based energetic material. Our investigations suggest that the enols like 1,3,5-triazine-2-ol could be the source of hydroxyl radicals, and their inclusion in the theoretical models is important to understand the unprecedented chemistry of explosive materials.
Collapse
Affiliation(s)
- Santosh K Singh
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Vasant Vuppuluri
- Mechanical Engineering, Purdue Energetics Research Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Bing-Jian Sun
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - Bo-Yu Chang
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - André K Eckhardt
- Department of Chemistry, MIT, Cambridge, Massachusetts 02139, United States
| | - Steven F Son
- Mechanical Engineering, Purdue Energetics Research Center, Purdue University, West Lafayette, Indiana 47907, United States
| | - Agnes H H Chang
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| |
Collapse
|
13
|
Chen X, Millet DB, Neuman JA, Veres PR, Ray EA, Commane R, Daube BC, McKain K, Schwarz JP, Katich JM, Froyd KD, Schill GP, Kim MJ, Crounse JD, Allen HM, Apel EC, Hornbrook RS, Blake DR, Nault BA, Campuzano-Jost P, Jimenez JL, Dibb JE. HCOOH in the remote atmosphere: Constraints from Atmospheric Tomography (ATom) airborne observations. ACS EARTH & SPACE CHEMISTRY 2021; 5:1436-1454. [PMID: 34164590 PMCID: PMC8216292 DOI: 10.1021/acsearthspacechem.1c00049] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Formic acid (HCOOH) is an important component of atmospheric acidity but its budget is poorly understood, with prior observations implying substantial missing sources. Here we combine pole-to-pole airborne observations from the Atmospheric Tomography Mission (ATom) with chemical transport model (GEOS-Chem CTM) and back trajectory analyses to provide the first global in-situ characterization of HCOOH in the remote atmosphere. ATom reveals sub-100 ppt HCOOH concentrations over most of the remote oceans, punctuated by large enhancements associated with continental outflow. Enhancements correlate with known combustion tracers and trajectory-based fire influences. The GEOS-Chem model underpredicts these in-plume HCOOH enhancements, but elsewhere we find no broad indication of a missing HCOOH source in the background free troposphere. We conclude that missing non-fire HCOOH precursors inferred previously are predominantly short-lived. We find indications of a wet scavenging underestimate in the model consistent with a positive HCOOH bias in the tropical upper troposphere. Observations reveal episodic evidence of ocean HCOOH uptake, which is well-captured by GEOS-Chem; however, despite its strong seawater undersaturation HCOOH is not consistently depleted in the remote marine boundary layer. Over fifty fire and mixed plumes were intercepted during ATom with widely varying transit times and source regions. HCOOH:CO normalized excess mixing ratios in these plumes range from 3.4 to >50 ppt/ppb CO and are often over an order of magnitude higher than expected primary emission ratios. HCOOH is thus a major reactive organic carbon reservoir in the aged plumes sampled during ATom, implying important missing pathways for in-plume HCOOH production.
Collapse
Affiliation(s)
- Xin Chen
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108
| | - Dylan B. Millet
- Department of Soil, Water, and Climate, University of Minnesota, St. Paul, MN 55108
| | - J. Andrew Neuman
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
| | | | - Eric A. Ray
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
| | - Róisín Commane
- Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, New York, NY 10964
| | - Bruce C. Daube
- Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138
| | - Kathryn McKain
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
- NOAA Global Monitoring Laboratory, Boulder, CO 80305
| | | | - Joseph M. Katich
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
| | - Karl D. Froyd
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
| | - Gregory P. Schill
- NOAA Chemical Sciences Laboratory, Boulder, CO 80305
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
| | - Michelle J. Kim
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - John D. Crounse
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Hannah M. Allen
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Eric C. Apel
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO 80307
| | - Rebecca S. Hornbrook
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO 80307
| | - Donald R. Blake
- Department of Chemistry, University of California, Irvine, CA 92697
| | - Benjamin A. Nault
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Pedro Campuzano-Jost
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Jose L. Jimenez
- Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309
- Department of Chemistry, University of Colorado Boulder, Boulder, CO 80309
| | - Jack E. Dibb
- Earth Systems Research Center/EOS, University of New Hampshire, Durham, NH 03824
| |
Collapse
|
14
|
Abstract
Machine learning (ML) techniques applied to chemical reactions have a long history. The present contribution discusses applications ranging from small molecule reaction dynamics to computational platforms for reaction planning. ML-based techniques can be particularly relevant for problems involving both computation and experiments. For one, Bayesian inference is a powerful approach to develop models consistent with knowledge from experiments. Second, ML-based methods can also be used to handle problems that are formally intractable using conventional approaches, such as exhaustive characterization of state-to-state information in reactive collisions. Finally, the explicit simulation of reactive networks as they occur in combustion has become possible using machine-learned neural network potentials. This review provides an overview of the questions that can and have been addressed using machine learning techniques, and an outlook discusses challenges in this diverse and stimulating field. It is concluded that ML applied to chemistry problems as practiced and conceived today has the potential to transform the way with which the field approaches problems involving chemical reactions, in both research and academic teaching.
Collapse
Affiliation(s)
- Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, Switzerland.,Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| |
Collapse
|
15
|
|
16
|
Ubiquitous atmospheric production of organic acids mediated by cloud droplets. Nature 2021; 593:233-237. [PMID: 33981052 PMCID: PMC8116209 DOI: 10.1038/s41586-021-03462-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/17/2021] [Indexed: 02/03/2023]
Abstract
Atmospheric acidity is increasingly determined by carbon dioxide and organic acids1-3. Among the latter, formic acid facilitates the nucleation of cloud droplets4 and contributes to the acidity of clouds and rainwater1,5. At present, chemistry-climate models greatly underestimate the atmospheric burden of formic acid, because key processes related to its sources and sinks remain poorly understood2,6-9. Here we present atmospheric chamber experiments that show that formaldehyde is efficiently converted to gaseous formic acid via a multiphase pathway that involves its hydrated form, methanediol. In warm cloud droplets, methanediol undergoes fast outgassing but slow dehydration. Using a chemistry-climate model, we estimate that the gas-phase oxidation of methanediol produces up to four times more formic acid than all other known chemical sources combined. Our findings reconcile model predictions and measurements of formic acid abundance. The additional formic acid burden increases atmospheric acidity by reducing the pH of clouds and rainwater by up to 0.3. The diol mechanism presented here probably applies to other aldehydes and may help to explain the high atmospheric levels of other organic acids that affect aerosol growth and cloud evolution.
Collapse
|
17
|
Käser S, Unke OT, Meuwly M. Isomerization and decomposition reactions of acetaldehyde relevant to atmospheric processes from dynamics simulations on neural network-based potential energy surfaces. J Chem Phys 2020; 152:214304. [DOI: 10.1063/5.0008223] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Silvan Käser
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Oliver T. Unke
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| | - Markus Meuwly
- Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland
| |
Collapse
|
18
|
Lei X, Wang W, Gao J, Wang S, Wang W. Atmospheric Chemistry of Enols: The Formation Mechanisms of Formic and Peroxyformic Acids in Ozonolysis of Vinyl Alcohol. J Phys Chem A 2020; 124:4271-4279. [PMID: 32369366 DOI: 10.1021/acs.jpca.0c01480] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vinyl alcohol (VA), for a long time, is thought to be a missing source of formic acid (FA) in the atmospheric models. However, a recent study has shown that FA is just a byproduct in the OH-initiated oxidation of VA, which stimulates investigation on the other sinks of VA in the atmosphere. In this study, the detailed ozonolysis mechanism of VA was investigated theoretically for the first time. The results show that two primary ozonides (syn- and anti-POZ) can be formed in the ozonolysis of VA and that FA coupled with the simplest Criegee intermediate (CH2OO) can be produced as the main nascent products. Thus, the ozonolysis of VA is predicted to be a more efficient process to produce FA in the atmosphere compared with its OH-initiated oxidation. Moreover, it is found that the syn-POZ can directly decompose to peroxyformic acid plus formaldehyde, breaking the known "Criegee mechanism" to form carbonyl oxide with carbonyl compound. This special mechanism by providing a new source of peroxy acids in the atmosphere enriches the atmospheric chemistry of enols. The atmospheric lifetime of VA by ozonolysis is predicted to be 30 h, comparable with its prevalent reaction with the OH radical. Therefore, the obtained theoretical results can be usefully incorporated into a future modeling study of enols.
Collapse
Affiliation(s)
- Xiaoyang Lei
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, Shaanxi, China
| | - Weina Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, Shaanxi, China
| | - Jiemiao Gao
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, Shaanxi, China
| | - Sainan Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, Guangdong, China
| | - Wenliang Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710119, Shaanxi, China
| |
Collapse
|
19
|
Long Y, Mamada M, Li C, dos Santos PL, Colella M, Danos A, Adachi C, Monkman A. Excited State Dynamics of Thermally Activated Delayed Fluorescence from an Excited State Intramolecular Proton Transfer System. J Phys Chem Lett 2020; 11:3305-3312. [PMID: 32255640 PMCID: PMC7304890 DOI: 10.1021/acs.jpclett.0c00498] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 04/03/2020] [Indexed: 05/30/2023]
Abstract
We describe the photophysical processes that give rise to thermally activated delayed fluorescence in the excited state intramolecular proton transfer (ESIPT) molecule, triquinolonobenzene (TQB). Using transient absorption and time-resolved photoluminescence spectroscopy, we fully characterize prompt and delayed emission, phosphorescence, and oxygen quenching to reveal the reverse intersystem crossing mechanism (rISC). After photoexcitation and rapid ESIPT to the TQB-TB tautomer, emission from S1 is found to compete with thermally activated ISC to an upper triplet state, T2, very close in energy to S1 and limiting photoluminescence quantum yield. T2 slowly decays to the lowest triplet state, T1, via internal conversion. In the presence of oxygen, T2 is quenched to the ground state of the double proton transferred TQB-TC tautomer. Our measurements demonstrate that rISC in TQB occurs from T2 to S1 driven by thermally activated reverse internal conversion from T1 to T2 and support recent calculations by Cao et al. (Cao, Y.; Eng, J.; Penfold, T. J. Excited State Intramolecular Proton Transfer Dynamics for Triplet Harvesting in Organic Molecules. J. Phys. Chem. A 2019, 123, 2640-2649).
Collapse
Affiliation(s)
- Yun Long
- Department
of Physics, Durham University, South Road, Durham DH1 3LE, United
Kingdom
| | - Masashi Mamada
- Center
for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- JST,
ERATO, Adachi Molecular Exciton Engineering Project c/o Center for
Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka 819-0395, Japan
- Academia-Industry
Molecular Systems for Devices Research and Education Center (AIMS), Kyushu University, Nishi, Fukuoka 819-0395, Japan
| | - Chunyong Li
- Department
of Physics, Durham University, South Road, Durham DH1 3LE, United
Kingdom
| | | | - Marco Colella
- Department
of Physics, Durham University, South Road, Durham DH1 3LE, United
Kingdom
| | - Andrew Danos
- Department
of Physics, Durham University, South Road, Durham DH1 3LE, United
Kingdom
| | - Chihaya Adachi
- Center
for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- JST,
ERATO, Adachi Molecular Exciton Engineering Project c/o Center for
Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka 819-0395, Japan
- Academia-Industry
Molecular Systems for Devices Research and Education Center (AIMS), Kyushu University, Nishi, Fukuoka 819-0395, Japan
- International
Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi, Fukuoka 819-0395, Japan
| | - Andrew Monkman
- Department
of Physics, Durham University, South Road, Durham DH1 3LE, United
Kingdom
| |
Collapse
|
20
|
Chen X, Millet DB, Singh HB, Wisthaler A, Apel EC, Atlas EL, Blake DR, Bourgeois I, Brown SS, Crounse JD, de Gouw JA, Flocke FM, Fried A, Heikes BG, Hornbrook RS, Mikoviny T, Min KE, Müller M, Neuman JA, O'Sullivan DW, Peischl J, Pfister GG, Richter D, Roberts JM, Ryerson TB, Shertz SR, Thompson CR, Treadaway V, Veres PR, Walega J, Warneke C, Washenfelder RA, Weibring P, Yuan B. On the sources and sinks of atmospheric VOCs: an integrated analysis of recent aircraft campaigns over North America. ATMOSPHERIC CHEMISTRY AND PHYSICS 2019; 19:9097-9123. [PMID: 33688334 PMCID: PMC7939023 DOI: 10.5194/acp-19-9097-2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We apply a high-resolution chemical transport model (GEOS-Chem CTM) with updated treatment of volatile organic compounds (VOCs) and a comprehensive suite of airborne datasets over North America to (i) characterize the VOC budget and (ii) test the ability of current models to capture the distribution and reactivity of atmospheric VOCs over this region. Biogenic emissions dominate the North American VOC budget in the model, accounting for 70 % and 95 % of annually emitted VOC carbon and reactivity, respectively. Based on current inventories anthropogenic emissions have declined to the point where biogenic emissions are the dominant summertime source of VOC reactivity even in most major North American cities. Methane oxidation is a 2x larger source of nonmethane VOCs (via production of formaldehyde and methyl hydroperoxide) over North America in the model than are anthropogenic emissions. However, anthropogenic VOCs account for over half of the ambient VOC loading over the majority of the region owing to their longer aggregate lifetime. Fires can be a significant VOC source episodically but are small on average. In the planetary boundary layer (PBL), the model exhibits skill in capturing observed variability in total VOC abundance (R 2 = 0:36) and reactivity (R 2 = 0:54). The same is not true in the free troposphere (FT), where skill is low and there is a persistent low model bias (~ 60 %), with most (27 of 34) model VOCs underestimated by more than a factor of 2. A comparison of PBL: FT concentration ratios over the southeastern US points to a misrepresentation of PBL ventilation as a contributor to these model FT biases. We also find that a relatively small number of VOCs (acetone, methanol, ethane, acetaldehyde, formaldehyde, isoprene C oxidation products, methyl hydroperoxide) drive a large fraction of total ambient VOC reactivity and associated model biases; research to improve understanding of their budgets is thus warranted. A source tracer analysis suggests a current overestimate of biogenic sources for hydroxyacetone, methyl ethyl ketone and glyoxal, an underestimate of biogenic formic acid sources, and an underestimate of peroxyacetic acid production across biogenic and anthropogenic precursors. Future work to improve model representations of vertical transport and to address the VOC biases discussed are needed to advance predictions of ozone and SOA formation.
Collapse
Affiliation(s)
- Xin Chen
- Department of Soil, Water, and Climate, University of Minnesota, Minneapolis-Saint Paul, MN, USA
| | - Dylan B. Millet
- Department of Soil, Water, and Climate, University of Minnesota, Minneapolis-Saint Paul, MN, USA
| | | | - Armin Wisthaler
- Institute for Ion Physics and Applied Physics, University of Innsbruck, 6020 Innsbruck, Austria
- Department of Chemistry, University of Oslo, Oslo, Norway
| | - Eric C. Apel
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Elliot L. Atlas
- Department of Atmospheric Sciences, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL, USA
| | - Donald R. Blake
- Department of Chemistry, University of California, Irvine, Irvine, CA, USA
| | - Ilann Bourgeois
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Steven S. Brown
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - John D. Crounse
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Joost A. de Gouw
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Frank M. Flocke
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Alan Fried
- Institute of Arctic & Alpine Research, University of Colorado, Boulder, CO, USA
| | - Brian G. Heikes
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA
| | - Rebecca S. Hornbrook
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Tomas Mikoviny
- Department of Chemistry, University of Oslo, Oslo, Norway
| | - Kyung-Eun Min
- School of Earth Science and Environmental Engineering, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Markus Müller
- Institute for Ion Physics and Applied Physics, University of Innsbruck, 6020 Innsbruck, Austria
| | - J. Andrew Neuman
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | | | - Jeff Peischl
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Gabriele G. Pfister
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Dirk Richter
- Institute of Arctic & Alpine Research, University of Colorado, Boulder, CO, USA
| | - James M. Roberts
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - Thomas B. Ryerson
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - Stephen R. Shertz
- Atmospheric Chemistry Observations & Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - Chelsea R. Thompson
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | - Victoria Treadaway
- Graduate School of Oceanography, University of Rhode Island, Narragansett, RI, USA
| | - Patrick R. Veres
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - James Walega
- Institute of Arctic & Alpine Research, University of Colorado, Boulder, CO, USA
| | - Carsten Warneke
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
| | | | - Petter Weibring
- Institute of Arctic & Alpine Research, University of Colorado, Boulder, CO, USA
| | - Bin Yuan
- Institute for Environmental and Climate Research, Jinan University, Guangzhou, China
| |
Collapse
|
21
|
Zhong J, Li H, Kumar M, Liu J, Liu L, Zhang X, Zeng XC, Francisco JS. Mechanistic Insight into the Reaction of Organic Acids with SO
3
at the Air–Water Interface. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201900534] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jie Zhong
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
| | - Hao Li
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Manoj Kumar
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
| | - Jiarong Liu
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Ling Liu
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Xiuhui Zhang
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Xiao Cheng Zeng
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Joseph S. Francisco
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
- Department of Earth and Environmental Science and Department of Chemistry University of Pennsylvania Philadelphia PA 19104-6316 USA
| |
Collapse
|
22
|
Zhong J, Li H, Kumar M, Liu J, Liu L, Zhang X, Zeng XC, Francisco JS. Mechanistic Insight into the Reaction of Organic Acids with SO
3
at the Air–Water Interface. Angew Chem Int Ed Engl 2019; 58:8351-8355. [DOI: 10.1002/anie.201900534] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/03/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Jie Zhong
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
| | - Hao Li
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Manoj Kumar
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
| | - Jiarong Liu
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Ling Liu
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Xiuhui Zhang
- Key Laboratory of Cluster Science Ministy of Education of China School of Chemistry Beijing Inistitute of Technology Beijing 100081 China
| | - Xiao Cheng Zeng
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Joseph S. Francisco
- Department of Chemistry University of Nebraska-Lincoln Lincoln NE 68588 USA
- Department of Earth and Environmental Science and Department of Chemistry University of Pennsylvania Philadelphia PA 19104-6316 USA
| |
Collapse
|
23
|
Lei X, Wang W, Cai J, Wang C, Liu F, Wang W. Atmospheric Chemistry of Enols: Vinyl Alcohol + OH + O2 Reaction Revisited. J Phys Chem A 2019; 123:3205-3213. [DOI: 10.1021/acs.jpca.8b12240] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xiaoyang Lei
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
| | - Weina Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
| | - Jie Cai
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
| | - Changwei Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
| | - Fengyi Liu
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
| | - Wenliang Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an 710062, Shaanxi, China
| |
Collapse
|
24
|
Alwe HD, Millet DB, Chen X, Raff JD, Payne ZC, Fledderman K. Oxidation of Volatile Organic Compounds as the Major Source of Formic Acid in a Mixed Forest Canopy. GEOPHYSICAL RESEARCH LETTERS 2019; 46:2940-2948. [PMID: 31068737 PMCID: PMC6487833 DOI: 10.1029/2018gl081526] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/24/2019] [Accepted: 02/15/2019] [Indexed: 05/22/2023]
Abstract
Formic acid (HCOOH) is among the most abundant carboxylic acids in the atmosphere, but its budget is poorly understood. We present eddy flux, vertical gradient, and soil chamber measurements from a mixed forest and apply the data to better constrain HCOOH source/sink pathways. While the cumulative above-canopy flux was downward, HCOOH exchange was bidirectional, with extended periods of net upward and downward flux. Net above-canopy fluxes were mostly upward during warmer/drier periods. The implied gross canopy HCOOH source corresponds to 3% and 38% of observed isoprene and monoterpene carbon emissions and is 15× underestimated in a state-of-science atmospheric model (GEOS-Chem). Gradient and soil chamber measurements identify the canopy layer as the controlling source of HCOOH or its precursors to the forest environment; below-canopy sources were minor. A correlation analysis using an ensemble of marker volatile organic compounds suggests that secondary formation, not direct emission, is the major source driving ambient HCOOH.
Collapse
Affiliation(s)
- Hariprasad D. Alwe
- Department of Soil, Water, and ClimateUniversity of Minnesota, Twin CitiesSaint PaulMNUSA
| | - Dylan B. Millet
- Department of Soil, Water, and ClimateUniversity of Minnesota, Twin CitiesSaint PaulMNUSA
| | - Xin Chen
- Department of Soil, Water, and ClimateUniversity of Minnesota, Twin CitiesSaint PaulMNUSA
| | - Jonathan D. Raff
- School of Public and Environmental AffairsIndiana UniversityBloomingtonINUSA
- Department of ChemistryIndiana UniversityBloomingtonINUSA
| | | | - Kathryn Fledderman
- School of Public and Environmental AffairsIndiana UniversityBloomingtonINUSA
| |
Collapse
|
25
|
Harrison AW, Kharazmi A, Shaw MF, Quinn MS, Lee KLK, Nauta K, Rowell KN, Jordan MJT, Kable SH. Dynamics and quantum yields of H2 + CH2CO as a primary photolysis channel in CH3CHO. Phys Chem Chem Phys 2019; 21:14284-14295. [DOI: 10.1039/c8cp06412a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new ketene + H2 channel in CH3CHO photolysis is not modelled by quasi-classical trajectories over the transition state.
Collapse
Affiliation(s)
| | - Alireza Kharazmi
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | | | | | - K. L. Kelvin Lee
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | - Klaas Nauta
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | - Keiran N. Rowell
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | | | - Scott H. Kable
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| |
Collapse
|