1
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Matsugi A, Suzuki S. Ring Growth Mechanism in the Reaction between Fulvenallenyl and Cyclopentadienyl Radicals. J Phys Chem A 2024; 128:1327-1338. [PMID: 38351621 DOI: 10.1021/acs.jpca.3c07441] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Recombination between resonance-stabilized hydrocarbon radicals is an important class of reactions that contribute to molecular growth chemistry in combustion. In the present study, the ring growth mechanism in the reaction between fulvenallenyl (C7H5) and cyclopentadienyl (C5H5) radicals is investigated computationally. The reaction pathways are explored by quantum chemical calculations, and the phenomenological and steady-state rate constants are determined by solving the multiple-well master equations. The primary reaction routes following the recombination between the two radicals are found to be as follows: formation of the adducts, isomerization by hydrogen shift reactions, cyclization to form tricyclic compounds, and their isomerization and dissociation reactions, leading to the formation of acenaphthylene. The overall process can be approximately represented as C7H5 + C5H5 → acenaphthylene + 2H with the bimolecular rate constant of about 4 × 10-12 cm3 molecule-1 s-1. A reaction mechanism consisting of 20 reactions, including the formation, isomerization, and dissociation processes of major intermediate species, is proposed for use in kinetic modeling.
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Affiliation(s)
- Akira Matsugi
- Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba 305-8569, Japan
| | - Shunsuke Suzuki
- Research Institute for Energy Conversion, National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba 305-8564, Japan
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2
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Goettl SJ, Turner AM, Sun BJ, Chang AHH, Hemberger P, Kaiser RI. Gas-phase preparation of the dibenzo[ e,l]pyrene (C 24H 14) butterfly molecule via a phenyl radical-mediated ring annulation. Chem Commun (Camb) 2024; 60:1404-1407. [PMID: 38174640 DOI: 10.1039/d3cc05371g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
A high temperature phenyl-mediated addition-cyclization-dehydrogenation mechanism to form peri-fused polycyclic aromatic hydrocarbon (PAH) derivatives-illustrated through the formation of dibenzo[e,l]pyrene (C24H14)-is explored through a gas-phase reaction of the phenyl radical (C6H5˙) with triphenylene (C18H12) utilizing photoelectron photoion coincidence spectroscopy (PEPICO) combined with electronic structure calculations. Low-lying vibrational modes of dibenzo[e,l]pyrene exhibit out-of-plane bending and are easily populated in high temperature environments such as combustion flames and circumstellar envelopes of carbon stars, thus stressing dibenzo[e,l]pyrene as a strong target for far-IR astronomical surveys.
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Affiliation(s)
- Shane J Goettl
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Andrew M Turner
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| | - Bing-Jian Sun
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan.
| | - Agnes H H Chang
- Department of Chemistry, National Dong Hwa University, Shoufeng, Hualien 974, Taiwan.
| | | | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
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3
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Qi Z, Zhang Z, Jin R, Zhang L, Zheng M, Li J, Wu Y, Li C, Lin B, Liu Y, Liu G. Target Analysis of Polychlorinated Naphthalenes and Nontarget Screening of Organic Chemicals in Bovine Milk, Infant Formula, and Adult Milk Powder by High-Resolution Mass Spectrometry. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:773-782. [PMID: 38109498 DOI: 10.1021/acs.jafc.3c07579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2023]
Abstract
Infant formula is intended as an effective substitute for breast milk but is the main source of polychlorinated naphthalenes (PCNs) to nonbreastfed infants. We performed target and nontarget analyses to determine PCNs and identify other organic contaminants in infant formula. The mean PCN concentrations in infant formula, milk powder, and bovine milk were 106.1, 88.8, and 78.2 μg kg-1 of dry weight, respectively. The PCN congener profiles indicated that thermal processes and raw materials were probably the main sources of PCNs in infant formula. A health risk assessment indicated that PCNs in infant formula do not pose health risks to infants. Using gas chromatography-Orbitrap mass spectrometry, 352, 372, and 161 organic chemicals were identified in the infant formula, milk powder, and bovine milk samples, respectively. Phthalate esters were detected in all four plastic-packed milk powder samples. The results indicated milk becomes more contaminated with organic chemicals during manufacturing, processing, and packaging.
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Affiliation(s)
- Ziyuan Qi
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zherui Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Rong Jin
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
| | - Lei Zhang
- China National Center for Food Safety Risk Assessment, Beijing 100021, P. R. China
| | - Minghui Zheng
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingguang Li
- China National Center for Food Safety Risk Assessment, Beijing 100021, P. R. China
| | - Yongning Wu
- China National Center for Food Safety Risk Assessment, Beijing 100021, P. R. China
| | - Cheng Li
- Institute of Quality Standard and Testing Technology, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, P. R. China
| | - Bingcheng Lin
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
| | - Yahui Liu
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
| | - Guorui Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- School of Environment, Hangzhou Institute for Advanced Study, UCAS, Hangzhou 310024, China
- College of Resource and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
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4
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Hermanns M, Wehres N, Heyne B, Honingh CE, Graf UU, Schlemmer S. Performance of a chirped-pulse Fourier transform millimeter wave spectrometer in the range of 75-110 GHz. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:034705. [PMID: 37012769 DOI: 10.1063/5.0141579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/21/2023] [Indexed: 06/19/2023]
Abstract
We present a home-built chirped-pulse Fourier transform millimeter wave (CP-FTMMW) spectrometer. The setup is devoted to the sensitive recording of high-resolution molecular spectroscopy in the W band between 75 and 110 GHz. We describe the experimental setup in detail, including a characterization of the chirp excitation source, the optical beam path, and the receiver. The receiver is a further development of our 100 GHz emission spectrometer. The spectrometer is equipped with a pulsed jet expansion and a DC discharge. Spectra of methyl cyanide as well as hydrogen cyanide (HCN) and hydrogen isocyanide (HNC) products from the DC discharge of this molecule are recorded to characterize the performance of the CP-FTMMW instrument. The formation of the HCN isomer is favored by a factor of 63 with respect to HNC. Hot/cold calibration measurements enable a direct comparison of the signal and noise levels of the CP-FTMMW spectra to those of the emission spectrometer. For the CP-FTMMW instrument, we find many orders of magnitude of signal enhancement and a much stronger noise reduction due to the coherent detection scheme.
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Affiliation(s)
- M Hermanns
- I. Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany
| | - N Wehres
- I. Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany
| | - B Heyne
- I. Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany
| | - C E Honingh
- I. Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany
| | - U U Graf
- I. Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany
| | - S Schlemmer
- I. Physikalisches Institut, Zülpicher Str. 77, 50937 Köln, Germany
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5
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Preitschopf T, Sturm F, Stroganova I, Lemmens AK, Rijs AM, Fischer I. IR/UV Double Resonance Study of the 2-Phenylallyl Radical and its Pyrolysis Products. Chemistry 2023; 29:e202202943. [PMID: 36479856 DOI: 10.1002/chem.202202943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/07/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022]
Abstract
Isolated 2-phenylallyl radicals (2-PA), generated by pyrolysis from a nitrite precursor, have been investigated by IR/UV ion dip spectroscopy using free electron laser radiation. 2-PA is a resonance-stabilized radical that is considered to be involved in the formation of polycyclic aromatic hydrocarbons (PAH) in combustion, but also in interstellar space. The radical is identified based on its gas-phase IR spectrum. Furthermore, a number of bimolecular reaction products are identified, showing that the self-reaction as well as reactions with unimolecular decomposition products of 2-PA form several PAH efficiently. Possible mechanisms are discussed and the chemistry of 2-PA is compared with the one of the related 2-methylallyl and phenylpropargyl radicals.
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Affiliation(s)
- Tobias Preitschopf
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Floriane Sturm
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Iuliia Stroganova
- Division of BioAnalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Alexander K Lemmens
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED, Nijmegen, The Netherlands
| | - Anouk M Rijs
- Division of BioAnalytical Chemistry, AIMMS Amsterdam Institute of Molecular and Life Sciences, Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany
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6
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Liu L, Huo X, Zhang Z, Jiang R, Liu W, Zhu Q, Ren H. Effect of Methanol Additives on Soot Inhibition during n-Decane Pyrolysis. Ind Eng Chem Res 2022. [DOI: 10.1021/acs.iecr.2c02278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lu Liu
- School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Xiaoliu Huo
- School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Ziduan Zhang
- School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Rongpei Jiang
- Beijing Institute of Aerospace Testing Technology, Beijing 100074, P. R. China
| | - Weixiong Liu
- School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
| | - Quan Zhu
- School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
- Engineering Research Center of Combustion and Cooling for Aerospace Power, Ministry of Education, Sichuan University, Chengdu 610065, Sichuan, P. R. China
| | - Haisheng Ren
- School of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China
- Engineering Research Center of Combustion and Cooling for Aerospace Power, Ministry of Education, Sichuan University, Chengdu 610065, Sichuan, P. R. China
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7
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Park Y, Park S, Shin J, Lim M. Photodissociation dynamics of chlorobenzene and
4‐fluoroiodobenzene
in
CCl
4
probed using time‐resolved infrared spectroscopy. B KOREAN CHEM SOC 2022. [DOI: 10.1002/bkcs.12495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Yejin Park
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| | - Seongchul Park
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| | - Juhyang Shin
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
| | - Manho Lim
- Department of Chemistry and Chemical Institute for Functional Materials Pusan National University Busan Korea
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8
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Levey ZD, Laws BA, Sundar SP, Nauta K, Kable SH, da Silva G, Stanton JF, Schmidt TW. PAH Growth in Flames and Space: Formation of the Phenalenyl Radical. J Phys Chem A 2021; 126:101-108. [PMID: 34936357 DOI: 10.1021/acs.jpca.1c08310] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are intermediates in the formation of soot particles and interstellar grains. However, their formation mechanisms in combustion and interstellar environments are not fully understood. The production of tricyclic PAHs and, in particular, the conversion of a PAH containing a five-membered ring to one with a six-membered ring are of interest to explain PAH abundances in combustion processes. In the present work, resonant ionization mass spectrometry in conjunction with isotopic labeling is used to investigate the formation of the phenalenyl radical from acenaphthylene and methane in an electrical discharge. We show that in this environment the CH cycloaddition mechanism converts a five-membered ring to a six-membered ring. This mechanism can occur in tandem with other PAH formation mechanisms such as hydrogen abstraction/acetylene addition (HACA) to produce larger PAHs in flames and the interstellar medium.
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Affiliation(s)
- Zachariah D Levey
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Benjamin A Laws
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Srivathsan P Sundar
- Department of Chemical Engineering, The University of Melbourne, Parkville 3010, Australia
| | - Klaas Nauta
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Scott H Kable
- School of Chemistry, University of New South Wales, Sydney, NSW 2052, Australia
| | - Gabriel da Silva
- Department of Chemical Engineering, The University of Melbourne, Parkville 3010, Australia
| | - John F Stanton
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Timothy W Schmidt
- Centre of Excellence in Exciton Science, University of New South Wales, Sydney, NSW 2052, Australia
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9
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Couch DE, Zhang AJ, Taatjes CA, Hansen N. Experimental Observation of Hydrocarbon Growth by Resonance‐Stabilized Radical–Radical Chain Reaction. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202110929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- David E. Couch
- Gas Phase Chemical Physics Department Combustion Research Facility Sandia National Laboratories Livermore CA 94550 USA
| | - Angie J. Zhang
- Gas Phase Chemical Physics Department Combustion Research Facility Sandia National Laboratories Livermore CA 94550 USA
| | - Craig A. Taatjes
- Gas Phase Chemical Physics Department Combustion Research Facility Sandia National Laboratories Livermore CA 94550 USA
| | - Nils Hansen
- Gas Phase Chemical Physics Department Combustion Research Facility Sandia National Laboratories Livermore CA 94550 USA
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10
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Jin H, Ye L, Yang J, Jiang Y, Zhao L, Farooq A. Inception of Carbonaceous Nanostructures via Hydrogen-Abstraction Phenylacetylene-Addition Mechanism. J Am Chem Soc 2021; 143:20710-20716. [PMID: 34784469 DOI: 10.1021/jacs.1c08230] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sufficient experimental evidence has suggested that polycyclic aromatic hydrocarbons are the building blocks of carbonaceous nanostructures in combustion and circumstellar envelops of carbon-rich stars, but their fundamental formation mechanisms remain elusive. By exploring the reaction kinetics of phenylacetylene with 1-naphthyl/4-phenanthryl radicals, we provide compelling theoretical and experimental evidence for a novel and self-consistent hydrogen-abstraction phenylacetylene-addition (HAPaA) mechanism. HAPaA operates efficiently at both low and high temperatures, leading to the formation, expansion, and nucleation of peri-condensed aromatic hydrocarbons (PCAHs), which are otherwise difficult to synthesis via traditional hydrogen-abstraction acetylene/vinylacetylene-addition pathways. The HAPaA mechanism can be generalized to other α-alkynyl PCAHs and thus provides an alternative covalent bond bridge for PCAH combination via an acetylene linker. The proposed HAPaA mechanism may contribute toward a comprehensive understanding of soot formation, carbonaceous nanomaterials synthesis, and the origin and evolution of carbon in our galaxy.
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Affiliation(s)
- Hanfeng Jin
- Clean Combustion Research Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Lili Ye
- School of Chemical Engineering, Dalian University of Technology, Dalian, Liaoning 116024, China
| | - Jiuzhong Yang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Yu Jiang
- Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education and Hubei Key Laboratory of Catalysis and Materials Science, Hubei R&D Center of Hyperbranched Polymers Synthesis and Applications, South-Central University for Nationalities, Wuhan 430074, China
| | - Long Zhao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Aamir Farooq
- Clean Combustion Research Center, Physical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
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11
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Couch DE, Zhang AJ, Taatjes CA, Hansen N. Experimental Observation of Hydrocarbon Growth by Resonance-Stabilized Radical-Radical Chain Reaction. Angew Chem Int Ed Engl 2021; 60:27230-27235. [PMID: 34605134 DOI: 10.1002/anie.202110929] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Indexed: 01/08/2023]
Abstract
Rapid molecular-weight growth of hydrocarbons occurs in flames, in industrial synthesis, and potentially in cold astrochemical environments. A variety of high- and low-temperature chemical mechanisms have been proposed and confirmed, but more facile pathways may be needed to explain observations. We provide laboratory confirmation in a controlled pyrolysis environment of a recently proposed mechanism, radical-radical chain reactions of resonance-stabilized species. The recombination reaction of phenyl (c-C6 H5 ) and benzyl (c-C6 H5 CH2 ) radicals produces both diphenylmethane and diphenylmethyl radicals, the concentration of the latter increasing with rising temperature. A second phenyl addition to the product radical forms both triphenylmethane and triphenylmethyl radicals, confirming the propagation of radical-radical chain reactions under the experimental conditions of high temperature (1100-1600 K) and low pressure (ca. 3 kPa). Similar chain reactions may contribute to particle growth in flames, the interstellar medium, and industrial reactors.
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Affiliation(s)
- David E Couch
- Gas Phase Chemical Physics Department, Combustion Research Facility, Sandia National Laboratories, Livermore, CA, 94550, USA
| | - Angie J Zhang
- Gas Phase Chemical Physics Department, Combustion Research Facility, Sandia National Laboratories, Livermore, CA, 94550, USA
| | - Craig A Taatjes
- Gas Phase Chemical Physics Department, Combustion Research Facility, Sandia National Laboratories, Livermore, CA, 94550, USA
| | - Nils Hansen
- Gas Phase Chemical Physics Department, Combustion Research Facility, Sandia National Laboratories, Livermore, CA, 94550, USA
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12
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Bourgalais J, Carrasco N, Vettier L, Comby A, Descamps D, Petit S, Blanchet V, Gaudin J, Mairesse Y, Marty B. Aromatic Formation Promoted by Ion-Driven Radical Pathways in EUV Photochemical Experiments Simulating Titan's Atmospheric Chemistry. J Phys Chem A 2021; 125:3159-3168. [PMID: 33843236 DOI: 10.1021/acs.jpca.1c00324] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the atmosphere of Titan, Saturn's main satellite, molecular growth is initiated by 85.6 nm extreme ultraviolet (EUV) photons triggering a chemistry with charged and free-radical species. However, the respective contribution of these species to the complexification of matter is far from being known. This work presents a chemical analysis in order to contribute to a better understanding of aromatic formation pathways. A gas mixture of N2/CH4 (90/10%) within the closed SURFACAT reactor was irradiated at a relatively low pressure (0.1 mbar) and room temperature for 6 h by EUV photons (∼85.6 nm). The neutral molecules formed at the end of the irradiation were condensed in a cryogenic trap and analyzed by electron ionization mass spectrometry. An analysis of the dominant chemical pathways highlights the identification of benzene and toluene and underlies the importance of small ion and radical reactions. On the basis of the experimental results, a speculative mechanism based on sequential H-elimination/CH3-addition reactions is proposed for the growth of aromatics in Titan's atmosphere. Elementary reactions to be studied are given to instill future updates of photochemical models of Titan's atmosphere.
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Affiliation(s)
- Jérémy Bourgalais
- LATMOS-IPSL, Université Versailles St-Quentin, CNRS/INSU, Sorbonne Université, UPMC Univ. Paris 06, 11 boulevard d'Alembert, 78280 Guyancourt, France.,Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS-Université de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, F-54501 Vandoeuvre-lès-Nancy, France
| | - Nathalie Carrasco
- LATMOS-IPSL, Université Versailles St-Quentin, CNRS/INSU, Sorbonne Université, UPMC Univ. Paris 06, 11 boulevard d'Alembert, 78280 Guyancourt, France
| | - Ludovic Vettier
- LATMOS-IPSL, Université Versailles St-Quentin, CNRS/INSU, Sorbonne Université, UPMC Univ. Paris 06, 11 boulevard d'Alembert, 78280 Guyancourt, France
| | - Antoine Comby
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Dominique Descamps
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Stéphane Petit
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Valérie Blanchet
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Jérôme Gaudin
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Yann Mairesse
- CELIA, Université de Bordeaux - CNRS - CEA, UMR5107, 351 Cours de la Libération, F33405 Talence, France
| | - Bernard Marty
- Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS - Université de Lorraine, 15 rue Notre Dame des Pauvres, BP 20, F-54501 Vandoeuvre-lès-Nancy, France
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13
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Abstract
This Perspective presents recent advances in our knowledge of the fundamental elementary mechanisms involved in the low- and high-temperature molecular mass growth processes to polycyclic aromatic hydrocarbons in combustion systems and in extraterrestrial environments (hydrocarbon-rich atmospheres of planets and their moons, cold molecular clouds, circumstellar envelopes). Molecular beam studies combined with electronic structure calculations extracted five key elementary mechanisms: Hydrogen Abstraction-Acetylene Addition, Hydrogen Abstraction-Vinylacetylene Addition, Phenyl Addition-DehydroCyclization, Radical-Radical Reactions, and Methylidyne Addition-Cyclization-Aromatization. These studies, summarized here, provide compelling evidence that key classes of aromatic molecules can be synthesized in extreme environments covering low temperatures in molecular clouds (10 K) and hydrocarbon-rich atmospheres of planets and their moons (35-150 K) to high-temperature environments like circumstellar envelopes of carbon-rich Asymptotic Giant Branch Stars stars and combustion systems at temperatures above 1400 K thus shedding light on the aromatic universe we live in.
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Affiliation(s)
- Ralf I Kaiser
- Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, United States
| | - Nils Hansen
- Combustion Research Facility, Sandia National Laboratories, Livermore, California 94551, United States
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14
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Suzuki S, Kiuchi S, Kinoshita K, Takeda Y, Sakaida S, Konno M, Tanaka K, Oguma M. Formation of polycyclic aromatic hydrocarbons, benzofuran, and dibenzofuran in fuel-rich oxidation of toluene using a flow reactor. Phys Chem Chem Phys 2021; 23:6509-6525. [PMID: 33688862 DOI: 10.1039/d0cp06615j] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Recently, polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) have been attracting considerable attention owing to their high toxicity. Understanding their formation mechanism during combustion processes is important to control their emission. However, there are few studies that have quantitatively investigated OPAH formation in the fuel-rich oxidation of hydrocarbons, despite the availability of several studies on PAH formation. In this study, benzofuran and dibenzofuran as OPAHs were quantified in the fuel-rich oxidation of toluene using a flow reactor at atmospheric pressure in a temperature range of 1050-1350 K at equivalence ratios from 3.0 to 12.0 and residence times from 0.2 to 1.5 s. In addition to benzofuran and dibenzofuran, 4 types of monocyclic aromatic hydrocarbons and 19 types of PAHs were also evaluated. The experimental data obtained in this study were compared with those of the ethylene oxidation performed in our previous study. The existing kinetic model for PAH growth was modified based on several theoretical studies to predict the behavior of OPAHs with furan structures. The modified model showed significant improvements in the prediction of benzofuran and dibenzofuran formation. Based on the rate of production and sensitivity analysis using the modified model, the dominant reaction pathways of benzofuran and dibenzofuran were investigated.
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Affiliation(s)
- Shunsuke Suzuki
- Research Institute for Energy Conversion, National Institute of Advanced Industrial Science and Technology (AIST), 1-2-1 Namiki, Tsukuba 305-8564, Japan.
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15
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Xu M, Zhu B, Zhao L, Sun Y, Pan Y, Yang J. Atmospheric-Pressure Pyrolysis Study of Chlorobenzene Using Synchrotron Radiation Photoionization Mass Spectrometry. J Phys Chem A 2021; 125:1949-1957. [PMID: 33651613 DOI: 10.1021/acs.jpca.0c10413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The pyrolysis of chlorobenzene (C6H5Cl) at 760 Torr was studied in the temperature range of 873-1223 K. The pyrolysis products including intermediates and chlorinated aromatics were detected and quantified via synchrotron radiation photoionization mass spectrometry. Furthermore, the photoionization cross sections of chlorobenzene were experimentally measured. On the basis of the experimental results, the decomposition pathways of chlorobenzene were discussed as well as the generation and consumption pathways of the main products. Benzene is the main product of chlorobenzene pyrolysis. Chlorobiphenyl (C12H9Cl), dichlorobiphenyl (C12H8Cl2), and chlorotriphenylene (C18H11Cl) predominated in trace chlorinated aromatic products. Chlorobenzene decomposed initially to form two radicals [chlorophenyl (·C6H4Cl) and phenyl (·C6H5)] and the important intermediate o-benzyne (o-C6H4). The propagation processes of chlorinated aromatics, including polychlorinated naphthalenes and polychlorinated biphenyls, were mainly triggered by chlorobenzene, chlorophenyl, and benzene via the even-numbered-carbon growth mechanism. Besides, the small-molecule products such as acetylene (C2H2), 1,3,5-hexatriyne (C6H2), and diacetylene (C4H2) were formed via the bond cleavage of o-benzyne (o-C6H4).
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Affiliation(s)
- Minggao Xu
- School of Metallurgical Engineering, Anhui University of Technology, Maanshan 243002, People's Republic of China.,National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, Anhui, People's Republic of China
| | - Baozhong Zhu
- School of Metallurgical Engineering, Anhui University of Technology, Maanshan 243002, People's Republic of China.,National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, Anhui, People's Republic of China
| | - Long Zhao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, Anhui, People's Republic of China
| | - Yunlan Sun
- School of Metallurgical Engineering, Anhui University of Technology, Maanshan 243002, People's Republic of China.,School of Petroleum Engineering, Changzhou University, Changzhou 213164, Jiangsu, People's Republic of China
| | - Yang Pan
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, Anhui, People's Republic of China
| | - Jiuzhong Yang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, Anhui, People's Republic of China
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16
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Nucleation of soot: experimental assessment of the role of polycyclic aromatic hydrocarbon (PAH) dimers. Z PHYS CHEM 2020. [DOI: 10.1515/zpch-2020-1638] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The irreversible dimerization of polycyclic aromatic hydrocarbons (PAHs) – typically pyrene (C16H10) dimerization – is widely used in combustion chemistry models to describe the soot particle inception step. This paper concerns itself with the detection and identification of dimers of flame-synthesized PAH radicals and closed-shell molecules and an experimental assessment of the role of these PAH dimers for the nucleation of soot. To this end, flame-generated species were extracted from an inverse co-flow flame of ethylene at atmospheric pressure and immediately diluted with excess nitrogen before the mixture was analyzed using flame-sampling tandem mass spectrometry with collision-induced fragmentation. Signal at m/z = 404.157 (C32H20) and m/z = 452.157 (C36H20) were detected and identified as dimers of closed-shell C16H10 and C18H10 monomers, respectively. A complex between a C13H9 radical and a C24H12 closed-shell PAH was observed at m/z = 465.164 (C37H21). However, a rigorous analysis of the flame-sampled mass spectra as a function of the dilution ratio, defined as the ratio of the flow rates of the diluent nitrogen to the sampled gases, indicates that the observed dimers are not flame-born, but are produced in the sampling line. In agreement with theoretical considerations, this paper provides experimental evidence that pyrene dimers cannot be a key intermediate in particle inception at elevated flame temperatures.
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17
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Chang J, Pan W, Liu X, Xue Q, Fu J, Zhang A. The formation of PBDFs from the ortho-disubstituted phenol precursors: A comprehensive theoretical study on the PBDD/Fs formation from 2,4,6-tribromophenol. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 713:136657. [PMID: 31958733 DOI: 10.1016/j.scitotenv.2020.136657] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/08/2020] [Accepted: 01/10/2020] [Indexed: 06/10/2023]
Abstract
Bromophenols are known as direct precursors of the notorious polybrominated dibenzo-p-dioxin/dibenzofurans (PBDD/Fs). There is a long-held viewpoint that only the more toxic dioxin-type products could be formed from the ortho-disubstituted phenols, totally contrary to the experimental observations that both PBDDs and PBDFs are generated. To tackle the issue, the gaseous formation mechanism of PBDD/Fs from 2,4,6-tribromophenol (TBP), a typical ortho-disubstituted phenol, was investigated in this study. Firstly, the reactions between TBP and the active H radical produce three key radical species including the bromophenoxyl radical, the substituted phenyl radical and phenoxyl diradical. The self- and cross-combinations of these radical species and TBP yield not only the dioxin-type products 1,3,6,8-TeBDD and 1,3,7,9-TeBDD, but also the brominated dibenzofurans 1,3,6,8-TeBDF and 2,4,6,8-TeBDF. Notably, the reactions involving the phenyl C sites in the substituted phenyl and phenoxyl diradicals are demonstrated to be both thermodynamically and kinetically more favorable than those involving the bromophenoxyl radical and the TBP molecule. Most importantly, the findings of the present work are of great importance as it provides feasible pathways to form less toxic dibenzofuran-type products from the ortho-disubstituted phenols. These results will improve the understanding of the PBDD/Fs formation mechanism from phenol precursors.
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Affiliation(s)
- Jiamin Chang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China
| | - Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Xian Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China
| | - Qiao Xue
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Jianjie Fu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, PR China; Institute of Environment and Health, Jianghan University, Wuhan 430056, PR China.
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18
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Zhao L, Prendergast MB, Kaiser RI, Xu B, Ablikim U, Ahmed M, Sun B, Chen Y, Chang AHH, Mohamed RK, Fischer FR. Synthesis of Polycyclic Aromatic Hydrocarbons by Phenyl Addition–Dehydrocyclization: The Third Way. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201909876] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Long Zhao
- Department of Chemistry University of Hawaii at Manoa Honolulu Hawaii 96822 USA
| | | | - Ralf I. Kaiser
- Department of Chemistry University of Hawaii at Manoa Honolulu Hawaii 96822 USA
| | - Bo Xu
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Utuq Ablikim
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Musahid Ahmed
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Bing‐Jian Sun
- Department of Chemistry National Dong Hwa University Shoufeng Hualien 974 Taiwan, ROC
| | - Yue‐Lin Chen
- Department of Chemistry National Dong Hwa University Shoufeng Hualien 974 Taiwan, ROC
| | - Agnes H. H. Chang
- Department of Chemistry National Dong Hwa University Shoufeng Hualien 974 Taiwan, ROC
| | - Rana K. Mohamed
- Department of Chemistry University of Hawaii at Manoa Honolulu Hawaii 96822 USA
- Department of Chemistry University of California Berkeley Berkeley CA 94720 USA
| | - Felix R. Fischer
- Department of Chemistry University of California Berkeley Berkeley CA 94720 USA
- Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
- Kavli Energy Nano Sciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
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19
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Zhao L, Prendergast MB, Kaiser RI, Xu B, Ablikim U, Ahmed M, Sun B, Chen Y, Chang AHH, Mohamed RK, Fischer FR. Synthesis of Polycyclic Aromatic Hydrocarbons by Phenyl Addition–Dehydrocyclization: The Third Way. Angew Chem Int Ed Engl 2019; 58:17442-17450. [DOI: 10.1002/anie.201909876] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Long Zhao
- Department of Chemistry University of Hawaii at Manoa Honolulu Hawaii 96822 USA
| | | | - Ralf I. Kaiser
- Department of Chemistry University of Hawaii at Manoa Honolulu Hawaii 96822 USA
| | - Bo Xu
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Utuq Ablikim
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Musahid Ahmed
- Chemical Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - Bing‐Jian Sun
- Department of Chemistry National Dong Hwa University Shoufeng Hualien 974 Taiwan, ROC
| | - Yue‐Lin Chen
- Department of Chemistry National Dong Hwa University Shoufeng Hualien 974 Taiwan, ROC
| | - Agnes H. H. Chang
- Department of Chemistry National Dong Hwa University Shoufeng Hualien 974 Taiwan, ROC
| | - Rana K. Mohamed
- Department of Chemistry University of Hawaii at Manoa Honolulu Hawaii 96822 USA
- Department of Chemistry University of California Berkeley Berkeley CA 94720 USA
| | - Felix R. Fischer
- Department of Chemistry University of California Berkeley Berkeley CA 94720 USA
- Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
- Kavli Energy Nano Sciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
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20
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Bensabath T, Le MD, Monnier H, Glaude PA. Polycyclic aromatic hydrocarbon (PAH) formation during acetylene pyrolysis in tubular reactor under low pressure carburizing conditions. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.03.030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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21
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Mechanistic and Kinetic Study on Self-/Cross- Condensation of PCTA/DT Formation Mechanisms from Three Types of Radicals of 2,4-Dichlorothiophenol. Int J Mol Sci 2019; 20:ijms20112623. [PMID: 31141990 PMCID: PMC6600164 DOI: 10.3390/ijms20112623] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 05/24/2019] [Accepted: 05/26/2019] [Indexed: 01/28/2023] Open
Abstract
Chlorothiophenols (CTPs) are known to be key and direct precursors of polychlorinated thianthrene/dibenzothiophenes (PCTA/DTs). Self/cross-coupling of the chlorothiophenoxy radicals (CTPRs), sulfydryl-substituted phenyl radicals and thiophenoxyl diradicals evolving from CTPs are initial and important steps for PCTA/DT formation. In this study, quantum chemical calculations were carried out to investigate the homogenous gas-phase formation of PCTA/DTs from self/cross-coupling of 2,4-dichlorothiophenoxy radical (R1), 2-sulfydryl-3,5-dichlorophenyl radical (R2) and 3,5-dichlorothiophenoxyl diradical (DR) at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. The rate constants of crucial elementary steps were deduced over 600-1200 K, using canonical variational transition state theory with a small curvature tunneling contribution. For the formation of PCTAs, the S•/σ-C• condensation with both thiophenolic sulfur in one radical and ortho carbon in the other radical bonded to single electron is the most efficient sulfur-carbon coupling mode, and the ranking of the PCTA formation potential is DR + DR > R2 + DR > R1 + DR > R1 + R2 > R1 + R1. For the formation of PCDTs, the σ-C•/σ-C• coupling with both ortho carbon in the two radicals bonded to single electron is the energetically favored carbon-carbon coupling mode, and the ranking of the PCDT formation potential is: R2 + DR > R2 + R2 > R1 + DR > R1 + R2 > R1 + R1. The PCTA/DTs could be produced from R1, R2 and DR much more readily than PCDD/DFs from corresponding oxygen substituted radicals.
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22
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Fioroni M, Savage RE, DeYonker NJ. On the formation of phosphorous polycyclic aromatics hydrocarbons (PAPHs) in astrophysical environments. Phys Chem Chem Phys 2019; 21:8015-8021. [PMID: 30931458 DOI: 10.1039/c9cp00547a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of phosphorous-containing polycyclic aromatic hydrocarbons (PAPHs) in astrophysical contexts is proposed and analyzed by means of computational methods [B3LYP-D3BJ/ma-def2-TZVPP, MP2-F12, CCSD-F12b and CCSD(T)-F12b levels of theory]. A "bottom-up" approach based on a radical-neutral reaction scheme between acetylene (C2H2) and the CP radical was used investigating: (a) the synthesis of the first PAPH (C5H5P) "phosphinine"; (b) PAPH growth by addition of C2H2 to the C5H4P radical; (c) PAPH synthesis by addition reactions of one CP radical and nC2H2 to a neutral PAH. Results show: (I) the formation of the phosphinine radical has a strong thermodynamic tendency (-133.3 kcal mol-1) and kinetic barriers ≤5.4 kcal mol-1; (II) PAPH growth by nC2H2 addition on the radical phosphinine easily and exothermically produces radicals (1a- or 1-phospha-naphtalenes with kinetic barriers ≤7.1 kcal mol-1 and reaction free energies ≤-102.5 kcal mol-1); (III) the addition of a single CP + nC2H2 to a neutral benzene generates a complex chemistry where the main product is 2-phospha-naphtalene; (IV) because of the CP radical character, its barrierless addition to a PAH produces a resonant stabilized PAPH, becoming excellent candidates for addition reactions with neutral or radical hydrocarbons and PAHs; (V) the same energy trend between all four levels of theory continues a well-calibrated computational protocol to analyze complex organic reactions with astrochemical interest using electronic structure theory.
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Affiliation(s)
- Marco Fioroni
- 213 Smith Chemistry Building, The University of Memphis, Memphis, 38152, TN, USA.
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23
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Quantum Chemical and Kinetic Study on Radical/Molecule Formation Mechanism of Pre-Intermediates for PCTA/PT/DT/DFs from 2-Chlorothiophenol and 2-Chlorophenol Precursors. Int J Mol Sci 2019; 20:ijms20071542. [PMID: 30934774 PMCID: PMC6480007 DOI: 10.3390/ijms20071542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 03/16/2019] [Accepted: 03/22/2019] [Indexed: 12/31/2022] Open
Abstract
Polychlorinated phenoxathiins (PCPTs), polychlorinated dibenzothiophenes (PCDTs), and polychlorinated thianthrenes (PCTAs) are sulfur analogues of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/DFs). Chlorothiophenols (CTPs) and chlorophenols (CPs) are key precursors for the formation of PCTA/PT/DTs, which can react with H or OH to form chloro(thio)phenoxy radical, sulfydryl/hydroxyl-substituted phenyl radicals, and (thio)phenoxyl diradicals. However, previous radical/radical PCTA/DT formation mechanisms in the literature failed to explain the higher concentration of PCDTs than that of PCTAs under the pyrolysis or combustion conditions. In this work, a detailed thermodynamics and kinetic calculations were carried out to investigate the pre-intermediate formation for PCTA/PT/DTs from radical/molecule coupling of the 2-C(T)P with their key radical species. Our study showed that the radical/molecule coupling mechanism explains the gas-phase formation of PCTA/PT/DTs in both thermodynamic and kinetic perspectives. The S/C coupling modes to form thioether-(thio)enol intermediates are preferable over the O/C coupling modes to form ether-(thio)enol intermediates. Thus, although the radical/molecule coupling of chlorophenoxy radical with 2-C(T)P has no effect on the PCDD/PT formation, the radical/molecule coupling of chlorothiophenoxy radical with 2-C(T)P plays an important role in the PCTA/PT formation. Most importantly, the pre-PCDT intermediates formation pathways from the couplings of sulfydryl/hydroxyl-substituted phenyl radical with 2-C(T)P and (thio)phenoxyl diradicals with 2-C(T)P are more favorable than pre-PCTA/PT intermediates formation pathways from the coupling of chlorothiophenoxy radical with 2-C(T)P, which provides reasonable explanation for the high PCDT-to-PCTA ratio in the environment.
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24
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Formation Mechanism of Benzo(a)pyrene: One of the Most Carcinogenic Polycyclic Aromatic Hydrocarbons (PAH). Molecules 2019; 24:molecules24061040. [PMID: 30884744 PMCID: PMC6470522 DOI: 10.3390/molecules24061040] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/05/2019] [Accepted: 03/11/2019] [Indexed: 12/02/2022] Open
Abstract
The formation of polycyclic aromatic hydrocarbons (PAHs) is a strong global concern due to their harmful effects. To help the reduction of their emissions, a crucial understanding of their formation and a deep exploration of their growth mechanism is required. In the present work, the formation of benzo(a)pyrene was investigated computationally employing chrysene and benz(a)anthracene as starting materials. It was assumed a type of methyl addition/cyclization (MAC) was the valid growth mechanism in this case. Consequently, the reactions implied addition reactions, ring closures, hydrogen abstractions and intramolecular hydrogen shifts. These steps of the mechanism were computed to explore benzo(a)pyene formation. The corresponding energies of the chemical species were determined via hybrid density funcional theory (DFT), B3LYP/6-31+G(d,p) and M06-2X/6-311++G(d,p). Results showed that the two reaction routes had very similar trends energetically, the difference between the energy levels of the corresponding molecules was just 6.13 kJ/mol on average. The most stable structure was obtained in the benzo(a)anthracene pathway.
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25
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Lai L, Green WH. Thermochemistry and Kinetics of Intermolecular Addition of Radicals to Toluene and Alkylaromatics. J Phys Chem A 2019; 123:3176-3184. [DOI: 10.1021/acs.jpca.9b00817] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lawrence Lai
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - William H. Green
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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26
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Adamson BD, Skeen SA, Ahmed M, Hansen N. Detection of Aliphatically Bridged Multi-Core Polycyclic Aromatic Hydrocarbons in Sooting Flames with Atmospheric-Sampling High-Resolution Tandem Mass Spectrometry. J Phys Chem A 2018; 122:9338-9349. [PMID: 30415549 DOI: 10.1021/acs.jpca.8b08947] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper provides experimental evidence for the chemical structures of aliphatically substituted and bridged polycyclic aromatic hydrocarbon (PAH) species in gas-physe combustion environments. The identification of these single- and multicore aromatic species, which have been hypothesized to be important in PAH growth and soot nucleation, was made possible through a combination of sampling gaseous constituents from an atmospheric pressure inverse coflow diffusion flame of ethylene and high-resolution tandem mass spectrometry (MS-MS). In these experiments, the flame-sampled components were ionized using a continuous VUV lamp at 10.0 eV and the ions were subsequently fragmented through collisions with Ar atoms in a collision-induced dissociation (CID) process. The resulting fragment ions, which were separated using a reflectron time-of-flight mass spectrometer, were used to extract structural information about the sampled aromatic compounds. The high-resolution mass spectra revealed the presence of alkylated single-core aromatic compounds and the fragment ions that were observed correspond to the loss of saturated and unsaturated units containing up to a total of 6 carbon atoms. Furthermore, the aromatic structures that form the foundational building blocks of the larger PAHs were identified to be smaller single-ring and pericondensed aromatic species with repetitive structural features. For demonstrative purposes, details are provided for the CID of molecular ions at masses 202 and 434. Insights into the role of the aliphatically substituted and bridged aromatics in the reaction network of PAH growth chemistry were obtained from spatially resolved measurements of the flame. The experimental results are consistent with a growth mechanism in which alkylated aromatics are oxidized to form pericondensed ring structures or react and recombine with other aromatics to form larger, potentially three-dimensional, aliphatically bridged multicore aromatic hydrocarbons.
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Affiliation(s)
- B D Adamson
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - S A Skeen
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
| | - M Ahmed
- Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - N Hansen
- Combustion Research Facility , Sandia National Laboratories , Livermore , California 94551 , United States
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27
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Hirsch F, Constantinidis P, Fischer I, Bakels S, Rijs AM. Dimerization of the Benzyl Radical in a High-Temperature Pyrolysis Reactor Investigated by IR/UV Ion Dip Spectroscopy. Chemistry 2018. [PMID: 29528193 DOI: 10.1002/chem.201800852] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We investigate the self-reaction of benzyl, C7 H7 , in a high-temperature pyrolysis reactor. The work is motivated by the observation that resonance-stabilized benzyl radicals can accumulate in reactive environments and contribute to the formation of polycyclic aromatic hydrocarbons (PAHs) and soot. Reaction products are detected by IR/UV ion dip spectroscopy, using infrared radiation from the free electron laser FELIX, and are identified by comparison with computed spectra. Among the reaction products identified by their IR absorption are several PAHs linked to toluene combustion such as bibenzyl, phenanthrene, diphenylmethane, and fluorene. The identification of 9,10-dihydrophenanthrene provides evidence for a mechanism of phenanthrene formation from bibenzyl that proceeds by initial cyclization rather than an initial hydrogen loss to stilbene.
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Affiliation(s)
- Florian Hirsch
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland Süd, 97074, Würzburg, Germany
| | - Philipp Constantinidis
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland Süd, 97074, Würzburg, Germany
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, University of Würzburg, Am Hubland Süd, 97074, Würzburg, Germany
| | - Sjors Bakels
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7-c, 6525 ED, Nijmegen, The Netherlands
| | - Anouk M Rijs
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7-c, 6525 ED, Nijmegen, The Netherlands
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28
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Ruwe L, Moshammer K, Hansen N, Kohse-Höinghaus K. Influences of the molecular fuel structure on combustion reactions towards soot precursors in selected alkane and alkene flames. Phys Chem Chem Phys 2018; 20:10780-10795. [PMID: 29392266 DOI: 10.1039/c7cp07743b] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this study, we experimentally investigate the high-temperature oxidation kinetics of n-pentane, 1-pentene and 2-methyl-2-butene (2M2B) in a combustion environment using flame-sampling molecular beam mass spectrometry. The selected C5 fuels are prototypes for linear and branched, saturated and unsaturated fuel components, featuring different C-C and C-H bond structures. It is shown that the formation tendency of species, such as polycyclic aromatic hydrocarbons (PAHs), yielded through mass growth reactions increases drastically in the sequence n-pentane < 1-pentene < 2M2B. This comparative study enables valuable insights into fuel-dependent reaction sequences of the gas-phase combustion mechanism that provide explanations for the observed difference in the PAH formation tendency. First, we investigate the fuel-structure-dependent formation of small hydrocarbon species that are yielded as intermediate species during the fuel decomposition, because these species are at the origin of the subsequent mass growth reaction pathways. Second, we review typical PAH formation reactions inspecting repetitive growth sequences in dependence of the molecular fuel structure. Third, we discuss how differences in the intermediate species pool influence the formation reactions of key aromatic ring species that are important for the PAH growth process underlying soot formation. As a main result it was found that for the fuels featuring a C[double bond, length as m-dash]C double bond, the chemistry of their allylic fuel radicals and their decomposition products strongly influences the combination reactions to the initially formed aromatic ring species and as a consequence, the PAH formation tendency.
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Affiliation(s)
- Lena Ruwe
- Department of Chemistry, Bielefeld University, Universitätsstraße 25, D-33615 Bielefeld, Germany.
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29
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Treatment of penicillin with supercritical water oxidation: Experimental study of combined ReaxFF molecular dynamics. KOREAN J CHEM ENG 2018. [DOI: 10.1007/s11814-017-0341-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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30
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Yu X, Chang J, Liu X, Pan W, Zhang A. Theoretical study on the formation mechanism of polychlorinated dibenzothiophenes/thianthrenes from 2-chlorothiophenol molecules. J Environ Sci (China) 2018; 66:318-327. [PMID: 29628101 DOI: 10.1016/j.jes.2017.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/04/2017] [Indexed: 06/08/2023]
Abstract
Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes (PCDT/TAs), sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs), has been well-documented to occur via radical-radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol (2-CTP) as a model compound for chlorothiophenols, we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self- and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene (1-MCTA), 1,6-dichlorothianthrene (1,6-DCTA), 4,6-dichlorodibenzothiophene (4,6-DCDT) and 1,6-dichlorodibenzothiophene (1,6-DCDT). The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists.
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Affiliation(s)
- Xiaoqing Yu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jiamin Chang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Xian Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Wenxiao Pan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
| | - Aiqian Zhang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100190, China.
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Mimura K, Nishida T. Hydrogen and Hydrocarbon Gases, Polycyclic Aromatic Hydrocarbons, and Amorphous Carbon Produced by Multiple Shock Compression of Liquid Benzene up to 27.4 GPa. J Phys Chem A 2017; 121:6471-6480. [PMID: 28787165 DOI: 10.1021/acs.jpca.7b06627] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Phase diagrams of benzene have been reported on the basis of data mainly obtained from static compression at various pressure-temperature, P-T, conditions. However, there are few data in the high-pressure and high temperature-region of the phase diagram. To understand the physical and chemical behavior of benzene in that region, multiple shock compression of benzene was evaluated by a recovery experimental system that directly analyzed the shocked samples. The shocked samples were composed of the remaining benzene, gases (H2, CH4, C2H4, C2H6, C3H6, and C3H8), polycyclic aromatic hydrocarbons with molecular weights from 128 (naphthalene) to 300 (coronene), and amorphous carbon. The abundances of these chemical species varied according to the P-T conditions induced by shock compression. Samples in the lower-pressure and lower-temperature region of the a-C:H phase in the phase diagram contained a significant amount of benzene as well as amorphous carbon. In the higher-pressure and higher-temperature region of the a-C:H phase, benzene was mostly converted into amorphous carbon (H/C = 0.2), H2, and CH4. Therefore, the amorphous carbon in the present study was produced by a different pathway than that in previous studies that have detected hydrogenated amorphous carbon (H/C = 1). For earth sciences, the present study can provide basic information on the delivery to the early earth of extraterrestrial organic materials related to the origin of life.
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Affiliation(s)
- Koichi Mimura
- Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya 464-8601, Japan
| | - Tamihito Nishida
- Department of Earth and Environmental Sciences, Graduate School of Environmental Studies, Nagoya University , Nagoya 464-8601, Japan
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32
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Gong Y, Guo Y, Wang S, Song W, Xu D. Supercritical water oxidation of quinazoline: Reaction kinetics and modeling. WATER RESEARCH 2017; 110:56-65. [PMID: 27988418 DOI: 10.1016/j.watres.2016.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 12/06/2016] [Accepted: 12/10/2016] [Indexed: 06/06/2023]
Abstract
This paper presents a first quantitative kinetic model for supercritical water oxidation (SCWO) of quinazoline that describes the formation and interconversion of intermediates and final products at 673-873 K. The set of 11 reaction pathways for phenol, pyrimidine, naphthalene, NH3, etc, involved in the simplified reaction network proved sufficient for fitting the experimental results satisfactorily. We validated the model prediction ability on CO2 yields at initial quinazoline loading not used in the parameter estimation. Reaction rate analysis and sensitivity analysis indicate that nearly all reactions reach their thermodynamic equilibrium within 300 s. The pyrimidine yielding from quinazoline is the dominant ring-opening pathway and provides a significant contribution to CO2 formation. Low sensitivity of NH3 decomposition rate to concentration confirms its refractory nature in SCWO. Nitrogen content in liquid products decreases whereas that in gaseous phase increases as reaction time prolonged. The nitrogen predicted by the model in gaseous phase combined with the experimental nitrogen in liquid products gives an accurate nitrogen balance of conversion process.
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Affiliation(s)
- Yanmeng Gong
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China; Jiangsu Provincial Academy of Environmental Science, Jiangsu Province Key Laboratory of Environmental Engineering, Nanjing, Jiangsu, 210036, China
| | - Yang Guo
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China; Xi'an Jiaotong University Suzhou Academy, Suzhou, Jiangsu, 215123, China.
| | - Shuzhong Wang
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Wenhan Song
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Donghai Xu
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
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33
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Ince A, Carstensen H, Sabbe M, Reyniers M, Marin GB. Group additive modeling of substituent effects in monocyclic aromatic hydrocarbon radicals. AIChE J 2016. [DOI: 10.1002/aic.15588] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Alper Ince
- Laboratory for Chemical TechnologyGhent University, Technologypark 914GhentB‐9052 Belgium
| | | | - Maarten Sabbe
- Laboratory for Chemical TechnologyGhent University, Technologypark 914GhentB‐9052 Belgium
| | | | - Guy B. Marin
- Laboratory for Chemical TechnologyGhent University, Technologypark 914GhentB‐9052 Belgium
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Gong Y, Guo Y, Wang S, Song W. Supercritical water oxidation of Quinazoline: Effects of conversion parameters and reaction mechanism. WATER RESEARCH 2016; 100:116-125. [PMID: 27179598 DOI: 10.1016/j.watres.2016.05.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/29/2016] [Accepted: 05/01/2016] [Indexed: 06/05/2023]
Abstract
The supercritical water oxidation reaction of quinazoline and a set of related reaction products were investigated in batch reactors by varying the temperature (T, 400-600 °C), time (t, 0-400 s), water density (ρ, 70.79-166.28 kg m(-3)) and oxidation coefficient (OC, 0-4.0). The TOC removal efficiency (CRE) increased significantly as the OC increased, whereas this effect was very limited at high OC (>2.0). Lack of oxygen resulted in low CRE and TN removal efficiency (NRE), also cause coke-formation, and giving high yield of NH3 and nitrogenous organic intermediates. Prolonging reaction time did not provide an appreciable improvement on CRE but remarkably increased NRE at temperature higher than 500 °C. Pyrimidines and pyridines as the nitrogenous intermediates were largely found in GC-MS spectrum. Polymerization among benzene, phenyl radical and benzyl radical played important roles in the formation of PAHs, such as naphthalene, biphenyl, phenanthrene. These collective results showed how the yield of intermediate products responded to changes in the process variables, which permitted the development of a potential reaction network for supercritical water oxidation of quinazoline.
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Affiliation(s)
- Yanmeng Gong
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Yang Guo
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China.
| | - Shuzhong Wang
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
| | - Wenhan Song
- Key Laboratory of Thermo-Fluid Science and Engineering, Ministry of Education, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China
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35
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Yang T, Parker DSN, Dangi BB, Kaiser RI, Mebel AM. Formation of 5- and 6-methyl-1H-indene (C10H10) via the reactions of the para-tolyl radical (C6H4CH3) with allene (H2CCCH2) and methylacetylene (HCCCH3) under single collision conditions. Phys Chem Chem Phys 2015; 17:10510-9. [DOI: 10.1039/c4cp04288c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Flux contour map for the reactions of the p-tolyl radical with allene-d4 and methylacetylene-d4 at collision energies of around 48 kJ mol−1.
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Affiliation(s)
- Tao Yang
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | | | - Beni B. Dangi
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Ralf I. Kaiser
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry
- Florida International University
- Miami
- USA
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36
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Muzangwa LG, Yang T, Parker DSN, Kaiser RI, Mebel AM, Jamal A, Ryazantsev M, Morokuma K. A crossed molecular beam and ab initio study on the formation of 5- and 6-methyl-1,4-dihydronaphthalene (C11H12) via the reaction of meta-tolyl (C7H7) with 1,3-butadiene (C4H6). Phys Chem Chem Phys 2015; 17:7699-706. [DOI: 10.1039/c5cp00311c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The crossed molecular beam reactions of the meta-tolyl radical with 1,3-butadiene and D6-1,3-butadiene were conducted at collision energies of 48.5 kJ mol−1 and 51.7 kJ mol−1.
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Affiliation(s)
| | - Tao Yang
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | | | - Ralf. I. Kaiser
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry
- Florida International University
- Miami
- USA
| | - Adeel Jamal
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation
- Emory University
- Atlanta
- USA
| | - Mikhail Ryazantsev
- Biomolecular NMR Laboratory
- St. Petersburg State University
- St. Petersburg
- Russia
| | - Keiji Morokuma
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation
- Emory University
- Atlanta
- USA
- Fukui Institute for Fundamental Chemistry
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37
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Yang T, Muzangwa L, Parker DSN, Kaiser RI, Mebel AM. Formation of 2- and 1-methyl-1,4-dihydronaphthalene isomers via the crossed beam reactions of phenyl radicals (C6H5) with isoprene (CH2C(CH3)CHCH2) and 1,3-pentadiene (CH2CHCHCHCH3). Phys Chem Chem Phys 2015; 17:530-40. [DOI: 10.1039/c4cp04612a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Crossed molecular beam reactions were exploited to elucidate the chemical dynamics of the reactions of phenyl radicals with isoprene and with 1,3-pentadiene at a collision energy of 55 ± 4 kJ mol−1.
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Affiliation(s)
- Tao Yang
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Lloyd Muzangwa
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | | | - Ralf I. Kaiser
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry
- Florida International University
- Miami
- USA
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38
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Yang T, Muzangwa L, Kaiser RI, Jamal A, Morokuma K. A combined crossed molecular beam and theoretical investigation of the reaction of the meta-tolyl radical with vinylacetylene – toward the formation of methylnaphthalenes. Phys Chem Chem Phys 2015. [DOI: 10.1039/c5cp03285g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Flux contour map for the reactive scattering channel of meta-tolyl radical with vinylacetylene.
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Affiliation(s)
- Tao Yang
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Lloyd Muzangwa
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Ralf I. Kaiser
- Department of Chemistry
- University of Hawaii at Manoa
- Honolulu
- USA
| | - Adeel Jamal
- Fukui Institute for Fundamental Chemistry
- Kyoto University
- Sakyo
- Japan
| | - Keiji Morokuma
- Fukui Institute for Fundamental Chemistry
- Kyoto University
- Sakyo
- Japan
- Department of Chemistry and Cherry L. Emerson Center for Scientific Computation
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39
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Cole-Filipiak NC, Shapero M, Negru B, Neumark DM. Revisiting the photodissociation dynamics of the phenyl radical. J Chem Phys 2014; 141:104307. [DOI: 10.1063/1.4894398] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Neil C. Cole-Filipiak
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Mark Shapero
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Bogdan Negru
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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40
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Dangi BB, Parker DSN, Yang T, Kaiser RI, Mebel AM. Gas-Phase Synthesis of the Benzyl Radical (C 6H 5CH 2). Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201310612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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41
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Dangi BB, Parker DSN, Yang T, Kaiser RI, Mebel AM. Gas-Phase Synthesis of the Benzyl Radical (C6H5CH2). Angew Chem Int Ed Engl 2014; 53:4608-13. [DOI: 10.1002/anie.201310612] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/25/2014] [Indexed: 11/10/2022]
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42
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Zhang Y, Zhang D, Gao J, Zhan J, Liu C. New Understanding of the Formation of PCDD/Fs from Chlorophenol Precursors: A Mechanistic and Kinetic Study. J Phys Chem A 2014; 118:449-56. [DOI: 10.1021/jp410077g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yanfang Zhang
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
| | - Dongju Zhang
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
| | - Jun Gao
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
| | - Jinhua Zhan
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
| | - Chengbu Liu
- Institute of Theoretical Chemistry, Shandong University, Jinan 250100, P. R. China
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43
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Dangi BB, Yang T, Kaiser RI, Mebel AM. Reaction dynamics of the 4-methylphenyl radical (C6H4CH3; p-tolyl) with isoprene (C5H8) – formation of dimethyldihydronaphthalenes. Phys Chem Chem Phys 2014; 16:16805-14. [DOI: 10.1039/c4cp01056f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction dynamics and energetics of 4-methylphenyl radical with isoprene are reported under single collision condition at collision energy of 58 kJ mol−1 by exploiting the crossed molecular beam technique and electronic structure calculations.
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Affiliation(s)
- Beni B. Dangi
- Department of Chemistry
- University of Hawai'i at Manoa
- Honolulu, USA
| | - Tao Yang
- Department of Chemistry
- University of Hawai'i at Manoa
- Honolulu, USA
| | - Ralf I. Kaiser
- Department of Chemistry
- University of Hawai'i at Manoa
- Honolulu, USA
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry
- Florida International University
- Miami, USA
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44
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Martin-Drumel MA, Pirali O, Falvo C, Parneix P, Gamboa A, Calvo F, Bréchignac P. Low-energy vibrational spectra of flexible diphenyl molecules: biphenyl, diphenylmethane, bibenzyl and 2-, 3- and 4-phenyltoluene. Phys Chem Chem Phys 2014; 16:22062-72. [DOI: 10.1039/c4cp03278k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas phase spectra of six bi-phenyl molecules are reported allowing an accurate determination of their active low-frequency vibrational modes.
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Affiliation(s)
- M. A. Martin-Drumel
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS, Université Paris-Sud
- 91405 Orsay Cedex, France
- SOLEIL Synchrotron
- L'orme des Merisiers
| | - O. Pirali
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS, Université Paris-Sud
- 91405 Orsay Cedex, France
- SOLEIL Synchrotron
- L'orme des Merisiers
| | - C. Falvo
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS, Université Paris-Sud
- 91405 Orsay Cedex, France
| | - P. Parneix
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS, Université Paris-Sud
- 91405 Orsay Cedex, France
| | - A. Gamboa
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS, Université Paris-Sud
- 91405 Orsay Cedex, France
| | - F. Calvo
- Laboratoire Interdisciplinaire de Physique (LIPhy)
- Grenoble, France
| | - Ph. Bréchignac
- Institut des Sciences Moléculaires d'Orsay (ISMO)
- CNRS, Université Paris-Sud
- 91405 Orsay Cedex, France
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45
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Sandhiya L, Senthilkumar K. Reaction mechanism and kinetics of the degradation of bromoxynil initiated by OH radical. RSC Adv 2014. [DOI: 10.1039/c3ra47334a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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46
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Yan H, Lu C, Jing D, Hou X. Chemical degradation of TGDDM/DDS epoxy resin in supercritical 1-propanol: Promotion effect of hydrogenation on thermolysis. Polym Degrad Stab 2013. [DOI: 10.1016/j.polymdegradstab.2013.09.026] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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47
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Kim JB, Weichman ML, Yacovitch TI, Shih C, Neumark DM. Slow photoelectron velocity-map imaging spectroscopy of the C9H7 (indenyl) and C13H9 (fluorenyl) anions. J Chem Phys 2013; 139:104301. [DOI: 10.1063/1.4820138] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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48
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49
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Pan W, Zhang D, Han Z, Zhan J, Liu C. New insight into the formation mechanism of PCDD/Fs from 2-chlorophenol precursor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:8489-8498. [PMID: 23841483 DOI: 10.1021/es400632j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Chlorophenols are known as precursors of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The widely accepted formation mechanism of PCDD/Fs always assumes chlorophenoxy radicals as key and important intermediates. Based on the results of density functional theory calculations, the present work reports new insight into the formation mechanism of PCDD/Fs from chlorophenol precursors. Using 2-chlorophenol as a model compound of chlorophenols, we find that apart from the chlorinated phenoxy radical, the chlorinated phenyl radical and the chlorinated α-ketocarbene also have great potential for PCDD/F formation, which has scarcely been considered in previous literature. The calculations on the self- and cross-coupling reactions of the chlorophenoxy radical, the chlorinated phenyl radical and the chlorinated α-ketocarbene show that the formations of 1-MCDD, 1,6-DCDD, 4,6-DCDF, and 4-MCDF are both thermodynamically and kinetically favorable. In particular, some pathways involving the chlorinated phenyl radicals and the chlorinated α-ketocarbene are even energetically more favorable than those involving the chlorophenoxy radical. The calculated results may improve our understanding for the formation mechanism of PCDD/Fs from chlorophenol precursors and be informative to environmental scientists.
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Affiliation(s)
- Wenxiao Pan
- Key Laboratory of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, Shandong University , Jinan, 250100, PR China
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50
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Guo Y, Wang S, Huelsman CM, Savage PE. Products, pathways, and kinetics for reactions of indole under supercritical water gasification conditions. J Supercrit Fluids 2013. [DOI: 10.1016/j.supflu.2012.10.010] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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