1
|
Millar TJ. Concluding remarks: Faraday Discussion on astrochemistry at high resolution. Faraday Discuss 2023; 245:638-650. [PMID: 37482967 DOI: 10.1039/d3fd00131h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Fifty years on from the first detailed chemical kinetic modelling of astronomical sources, I provide some introductory comments on the history of astrochemistry, summarise some personal views on the topics covered in this discussion meeting, and conclude with some thoughts on its future development. I have left out the jokes.
Collapse
Affiliation(s)
- T J Millar
- Astrophysics Research Centre, Queen's University Belfast, University Road, Belfast BT7 1NN, UK.
| |
Collapse
|
2
|
Blitz MA, Onel L, Robertson SH, Seakins PW. Studies on the Kinetics of the CH + H 2 Reaction and Implications for the Reverse Reaction, 3CH 2 + H. J Phys Chem A 2023; 127:2367-2375. [PMID: 36857400 PMCID: PMC10026075 DOI: 10.1021/acs.jpca.2c08097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The reaction of CH radicals with H2 has been studied by the use of laser flash photolysis, probing CH decays under pseudo-first-order conditions using laser-induced fluorescence (LIF) over the temperature range 298-748 K at pressures of ∼5-100 Torr. Careful data analysis was required to separate the CH LIF signal at ∼428 nm from broad background fluorescence, and this interference increased with temperature. We believe that this interference may have been the source of anomalous pressure behavior reported previously in the literature (Brownsword, R. A.; J. Chem. Phys. 1997, 106, 7662-7677). The rate coefficient k1 shows complex behavior: at low pressures, the main route for the CH3* formed from the insertion of CH into H2 is the formation of 3CH2 + H, and as the pressure is increased, CH3* is increasingly stabilized to CH3. The kinetic data on CH + H2 have been combined with experimental shock tube data on methyl decomposition and literature thermochemistry within a master equation program to precisely determine the rate coefficient of the reverse reaction, 3CH2 + H → CH + H2. The resulting parametrization is kCH2+H(T) = (1.69 ± 0.11) × 10-10 × (T/298 K)(0.05±0.010) cm3 molecule-1 s-1, where the errors are 1σ.
Collapse
Affiliation(s)
- Mark A Blitz
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
- NCAS, University of Leeds, Leeds LS2 9JT, U.K
| | - Lavinia Onel
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| | | | - Paul W Seakins
- School of Chemistry, University of Leeds, Leeds LS2 9JT, U.K
| |
Collapse
|
3
|
Krikunova LI, Nikolayev AA, Porfiriev DP, Mebel AM. Reaction of propionitrile with methylidyne: A theoretical study. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202200461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Affiliation(s)
- Lubov I. Krikunova
- Samara National Research University Samara Russia
- Lebedev Physical Institute Samara Branch Samara Russia
| | - Anatoliy A. Nikolayev
- Samara National Research University Samara Russia
- Lebedev Physical Institute Samara Branch Samara Russia
| | - Denis P. Porfiriev
- Samara National Research University Samara Russia
- Lebedev Physical Institute Samara Branch Samara Russia
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry Florida International University Miami Florida USA
| |
Collapse
|
4
|
He C, Fujioka K, Nikolayev AA, Zhao L, Doddipatla S, Azyazov VN, Mebel AM, Sun R, Kaiser RI. A chemical dynamics study of the reaction of the methylidyne radical (CH, X 2Π) with dimethylacetylene (CH 3CCCH 3, X 1A 1g). Phys Chem Chem Phys 2021; 24:578-593. [PMID: 34908056 DOI: 10.1039/d1cp04443e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The gas-phase reaction of the methylidyne (CH; X2Π) radical with dimethylacetylene (CH3CCCH3; X1A1g) was studied at a collision energy of 20.6 kJ mol-1 under single collision conditions with experimental results merged with ab initio calculations of the potential energy surface (PES) and ab initio molecule dynamics (AIMD) simulations. The crossed molecular beam experiment reveals that the reaction proceeds barrierless via indirect scattering dynamics through long-lived C5H7 reaction intermediate(s) ultimately dissociating to C5H6 isomers along with atomic hydrogen with atomic hydrogen predominantly released from the methyl groups as verified by replacing the methylidyne with the D1-methylidyne reactant. AIMD simulations reveal that the reaction dynamics are statistical leading predominantly to p28 (1-methyl-3-methylenecyclopropene, 13%) and p8 (1-penten-3-yne, 81%) plus atomic hydrogen with a significant amount of available energy being channeled into the internal excitation of the polyatomic reaction products. The dynamics are controlled by addition to the carbon-carbon triple bond with the reaction intermediates eventually eliminating a hydrogen atom from the methyl groups of the dimethylacetylene reactant forming 1-methyl-3-methylenecyclopropene (p28). The dominating pathways reveal an unexpected insertion of methylidyne into one of the six carbon-hydrogen single bonds of the methyl groups of dimethylacetylene leading to the acyclic intermediate, which then decomposes to 1-penten-3-yne (p8). Therefore, the methyl groups of dimethylacetylene effectively 'screen' the carbon-carbon triple bond from being attacked by addition thus directing the dynamics to an insertion process as seen exclusively in the reaction of methylidyne with ethane (C2H6) forming propylene (CH3C2H3). Therefore, driven by the screening of the triple bond, one propynyl moiety (CH3CC) acts in four out of five trajectories as a spectator thus driving an unexpected, but dominating chemistry in analogy to the methylidyne - ethane system.
Collapse
Affiliation(s)
- Chao He
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Kazuumi Fujioka
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Anatoliy A Nikolayev
- Lebedev Physical Institute, Samara 443011, Russia.,Samara National Research University, Samara 443086, Russia
| | - Long Zhao
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Valeriy N Azyazov
- Lebedev Physical Institute, Samara 443011, Russia.,Samara National Research University, Samara 443086, Russia
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, USA.
| | - Rui Sun
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| |
Collapse
|
5
|
Caster KL, Selby TM, Osborn DL, Le Picard SD, Goulay F. Product Detection of the CH(X 2Π) Radical Reaction with Cyclopentadiene: A Novel Route to Benzene. J Phys Chem A 2021; 125:6927-6939. [PMID: 34374546 DOI: 10.1021/acs.jpca.1c03517] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of the methylidyne radical (CH(X2Π)) with cyclopentadiene (c-C5H6) is studied in the gas phase at 4 Torr and 373 K using a multiplexed photoionization mass spectrometer. Under multiple collision conditions, the dominant product channel observed is the formation of C6H6 + H. Fitting the photoionization spectrum using reference spectra allows for isomeric resolution of C6H6 isomers, where benzene is the largest contributor with a relative branching fraction of 90 (±5)%. Several other C6H6 isomers are found to have smaller contributions, including fulvene with a branching fraction of 8 (±5)%. Master Equation calculations for four different entrance channels on the C6H7 potential energy surface are performed to explore the competition between CH cycloaddition to a C═C bond vs CH insertion into C-H bonds of cyclopentadiene. Previous studies on CH addition to unsaturated hydrocarbons show little evidence for the C-H insertion pathway. The present computed branching fractions support benzene as the sole cyclic product from CH cycloaddition, whereas fulvene is the dominant product from two of the three pathways for CH insertion into the C-H bonds of cyclopentadiene. The combination of experiment with Master Equation calculations implies that insertion must account for ∼10 (±5)% of the overall CH + cyclopentadiene mechanism.
Collapse
Affiliation(s)
- Kacee L Caster
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Talitha M Selby
- Department of Mathematics and Natural Sciences, University of Wisconsin-Milwaukee, West Bend, Wisconsin 53095, United States
| | - David L Osborn
- Combustion Research Facility, Sandia National Laboratories, Mail Stop 9055, Livermore, California 94551, United States
| | - Sebastien D Le Picard
- IPR (Institut de Physique de Rennes), UMR 6251, Univ Rennes, CNRS, F-35000 Rennes, France
| | - Fabien Goulay
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
6
|
Cernicharo J, Agúndez M, Cabezas C, Tercero B, Marcelino N, Pardo JR, de Vicente P. Pure hydrocarbon cycles in TMC-1: Discovery of ethynyl cyclopropenylidene, cyclopentadiene and indene. ASTRONOMY AND ASTROPHYSICS 2021; 649:L15. [PMID: 34257463 PMCID: PMC7611194 DOI: 10.1051/0004-6361/202141156] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the detection for the first time in space of three new pure hydrocarbon cycles in TMC-1: c-C3HCCH (ethynyl cyclopropenylidene), c-C5H6 (cyclopentadiene) and c-C9H8 (indene). We derive a column density of 3.1 × 1011 cm-2 for the former cycle and similar values, in the range (1-2) × 1013 cm-2, for the two latter molecules. This means that cyclopentadiene and indene, in spite of their large size, are exceptionally abundant, only a factor of five less abundant than the ubiquitous cyclic hydrocarbon c-C3H2. The high abundance found for these two hydrocarbon cycles, together with the high abundance previously found for the propargyl radical (CH2CCH) and other hydrocarbons like vinyl and allenyl acetylene (Agúndez et al. 2021; Cernicharo et al. 2021a,b), start to allow us to quantify the abundant content of hydrocarbon rings in cold dark clouds and to identify the intermediate species that are probably behind the in situ bottom-up synthesis of aromatic cycles in these environments. While c-C3HCCH is most likely formed through the reaction between the radical CCH and c-C3H2, the high observed abundances of cyclopentadiene and indene are difficult to explain through currently proposed chemical mechanisms. Further studies are needed to identify how are five- and six-membered rings formed under the cold conditions of clouds like TMC-1.
Collapse
Affiliation(s)
- J. Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - M. Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - C. Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - B. Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (OAN, IGN), Madrid, Spain
| | - N. Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - J. R. Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/Serrano 121, 28006 Madrid, Spain
| | - P. de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| |
Collapse
|
7
|
Cernicharo J, Agúndez M, Cabezas C, Marcelino N, Tercero B, Pardo JR, Gallego JD, Tercero F, López-Pérez JA, de Vicente P. Discovery of CH 2CHCCH and detection of HCCN, HC 4N, CH 3CH 2CN, and, tentatively, CH 3CH 2CCH in TMC-1. ASTRONOMY AND ASTROPHYSICS 2021; 647:L2. [PMID: 33833468 PMCID: PMC7610549 DOI: 10.1051/0004-6361/202140434] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present the discovery in TMC-1 of vinyl acetylene, CH2CHCCH, and the detection, for the first time in a cold dark cloud, of HCCN, HC4N, and CH3CH2CN. A tentative detection of CH3CH2CCH is also reported. The column density of vinyl acetylene is (1.2±0.2)×1013 cm-2, which makes it one of the most abundant closed-shell hydrocarbons detected in TMC-1. Its abundance is only three times lower than that of propylene, CH3CHCH2. The column densities derived for HCCN and HC4N are (4.4±0.4)×1011 cm-2 and (3.7±0.4)×1011 cm-2, respectively. Hence, the HCCN/HC4N abundance ratio is 1.2±0.3. For ethyl cyanide we derive a column density of (1.1 ±0.3)×1011 cm-2. These results are compared with a state-of-the-art chemical model of TMC-1, which is able to account for the observed abundances of these molecules through gas-phase chemical routes.
Collapse
Affiliation(s)
- J Cernicharo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - M Agúndez
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - C Cabezas
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - N Marcelino
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - B Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
- Observatorio Astronómico Nacional (IGN), C/ Alfonso XII, 3, 28014, Madrid, Spain
| | - J R Pardo
- Grupo de Astrofísica Molecular, Instituto de Física Fundamental (IFF-CSIC), C/ Serrano 121, 28006 Madrid, Spain
| | - J D Gallego
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - F Tercero
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - J A López-Pérez
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| | - P de Vicente
- Centro de Desarrollos Tecnológicos, Observatorio de Yebes (IGN), 19141 Yebes, Guadalajara, Spain
| |
Collapse
|
8
|
Doddipatla S, Galimova GR, Wei H, Thomas AM, He C, Yang Z, Morozov AN, Shingledecker CN, Mebel AM, Kaiser RI. Low-temperature gas-phase formation of indene in the interstellar medium. SCIENCE ADVANCES 2021; 7:7/1/eabd4044. [PMID: 33523847 PMCID: PMC7775774 DOI: 10.1126/sciadv.abd4044] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/04/2020] [Indexed: 06/07/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) are fundamental molecular building blocks of fullerenes and carbonaceous nanostructures in the interstellar medium and in combustion systems. However, an understanding of the formation of aromatic molecules carrying five-membered rings-the essential building block of nonplanar PAHs-is still in its infancy. Exploiting crossed molecular beam experiments augmented by electronic structure calculations and astrochemical modeling, we reveal an unusual pathway leading to the formation of indene (C9H8)-the prototype aromatic molecule with a five-membered ring-via a barrierless bimolecular reaction involving the simplest organic radical-methylidyne (CH)-and styrene (C6H5C2H3) through the hitherto elusive methylidyne addition-cyclization-aromatization (MACA) mechanism. Through extensive structural reorganization of the carbon backbone, the incorporation of a five-membered ring may eventually lead to three-dimensional PAHs such as corannulene (C20H10) along with fullerenes (C60, C70), thus offering a new concept on the low-temperature chemistry of carbon in our galaxy.
Collapse
Affiliation(s)
- Srinivas Doddipatla
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Galiya R Galimova
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, 33199, USA
- Samara National Research University, Samara 443086, Russia
| | - Hongji Wei
- Department of Physics and Astronomy, Benedictine College, Atchison, KS 66002, USA
| | - Aaron M Thomas
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Chao He
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Zhenghai Yang
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Alexander N Morozov
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, 33199, USA
| | | | - Alexander M Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL, 33199, USA.
| | - Ralf I Kaiser
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
| |
Collapse
|
9
|
Li J, Geng C, Weiske T, Zhou M, Li J, Schwarz H. Revisiting the Intriguing Electronic Features of the BeOBeC Carbyne and Some Isomers: A Quantum-Chemical Assessment. Angew Chem Int Ed Engl 2020; 59:17261-17265. [PMID: 32568419 PMCID: PMC7540417 DOI: 10.1002/anie.202007990] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Indexed: 11/09/2022]
Abstract
Extensive high-level quantum-chemical calculations reveal that the rod-shaped molecule BeOBeC, which was recently generated in matrix experiments, exists in two nearly isoenergetic states, the 5 Σ quintet (5 6) and the 3 Σ triplet (3 6). Their IR features are hardly distinguishable at finite temperature. The major difference concerns the mode of spin coupling between the terminal beryllium and carbon atoms. Further, the ground-state potential-energy surface of the [2Be,C,O] system at 4 K is presented and differences between the photochemical and thermal behaviors are highlighted. Finally, a previously not considered, so far unknown C2v -symmetric rhombus-like four-membered ring 3 [Be(O)(C)Be] (3 5) is predicted to represent the global minimum on the potential-energy surface.
Collapse
Affiliation(s)
- Jilai Li
- Institute of Theoretical ChemistryJilin University130023ChangchunChina
- Institut für ChemieTechnische Universität Berlin10623BerlinGermany
| | - Caiyun Geng
- Institut für ChemieTechnische Universität Berlin10623BerlinGermany
| | - Thomas Weiske
- Institut für ChemieTechnische Universität Berlin10623BerlinGermany
| | - Mingfei Zhou
- Department of ChemistryCollaborative Innovation Center of Chemistry for Energy Materials Shanghai Key Laboratory of Molecular Catalysts and Innovative MaterialsFudan University200433ShanghaiChina
| | - Jun Li
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of EducationTsinghua University100084BeijingChina
- Department of ChemistrySouthern University of Science and Technology518055ShenzhenChina
| | - Helmut Schwarz
- Institut für ChemieTechnische Universität Berlin10623BerlinGermany
| |
Collapse
|
10
|
Li J, Geng C, Weiske T, Zhou M, Li J, Schwarz H. Revisiting the Intriguing Electronic Features of the BeOBeC Carbyne and Some Isomers: A Quantum‐Chemical Assessment. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jilai Li
- Institute of Theoretical Chemistry Jilin University 130023 Changchun China
- Institut für Chemie Technische Universität Berlin 10623 Berlin Germany
| | - Caiyun Geng
- Institut für Chemie Technische Universität Berlin 10623 Berlin Germany
| | - Thomas Weiske
- Institut für Chemie Technische Universität Berlin 10623 Berlin Germany
| | - Mingfei Zhou
- Department of Chemistry Collaborative Innovation Center of Chemistry for Energy Materials Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials Fudan University 200433 Shanghai China
| | - Jun Li
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education Tsinghua University 100084 Beijing China
- Department of Chemistry Southern University of Science and Technology 518055 Shenzhen China
| | - Helmut Schwarz
- Institut für Chemie Technische Universität Berlin 10623 Berlin Germany
| |
Collapse
|
11
|
Li WL, Zhang Q, Chen M, Hu HS, Li J, Zhou M. Formation and Characterization of a BeOBeC Multiple Radical Featuring a Quartet Carbyne Moiety. Angew Chem Int Ed Engl 2020; 59:6923-6928. [PMID: 32017342 DOI: 10.1002/anie.202000910] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 11/06/2022]
Abstract
Through reaction of beryllium dimers with carbon monoxide, a carbonyl complex BeBeCO is formed in solid neon. Upon visible light excitation, the BeBeCO complex rearranges to a BeCOBe isomer, which further isomerizes to a low-energy BeOBeC species under UV-visible light excitation. These species are identified on the basis of infrared absorption spectroscopy with isotopic substitutions and quantum chemical studies. The BeOBeC molecule is characterized to be a multiple radical species having an electronic quintet ground state featuring an unusual quartet carbyne unit with three unpaired electrons on the carbon center. Bonding analysis indicates that the strong Pauli repulsion between carbon 2s lone pair electrons and the σ electrons of the BeOBe fragment significantly weakens the Be-C bonding and destabilizes the triplet state of the BeOBeC radical with a doublet carbyne unit. The three-center π-bonding of BeOBe is also found to play a role in stabilizing the quartet carbyne.
Collapse
Affiliation(s)
- Wan-Lu Li
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing, 100084, China
| | - Qingnan Zhang
- Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Mohua Chen
- Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China
| | - Han-Shi Hu
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing, 100084, China
| | - Jun Li
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Tsinghua University, Beijing, 100084, China.,Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Mingfei Zhou
- Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai, 200433, China
| |
Collapse
|
12
|
Li W, Zhang Q, Chen M, Hu H, Li J, Zhou M. Formation and Characterization of a BeOBeC Multiple Radical Featuring a Quartet Carbyne Moiety. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202000910] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Wan‐Lu Li
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of EducationTsinghua University Beijing 100084 China
| | - Qingnan Zhang
- Department of ChemistryCollaborative Innovation Center of Chemistry for Energy MaterialsShanghai Key Laboratory of Molecular Catalysts and Innovative MaterialsFudan University Shanghai 200433 China
| | - Mohua Chen
- Department of ChemistryCollaborative Innovation Center of Chemistry for Energy MaterialsShanghai Key Laboratory of Molecular Catalysts and Innovative MaterialsFudan University Shanghai 200433 China
| | - Han‐Shi Hu
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of EducationTsinghua University Beijing 100084 China
| | - Jun Li
- Department of Chemistry & Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of EducationTsinghua University Beijing 100084 China
- Department of ChemistrySouthern University of Science and Technology Shenzhen 518055 China
| | - Mingfei Zhou
- Department of ChemistryCollaborative Innovation Center of Chemistry for Energy MaterialsShanghai Key Laboratory of Molecular Catalysts and Innovative MaterialsFudan University Shanghai 200433 China
| |
Collapse
|
13
|
He C, Thomas AM, Galimova GR, Mebel AM, Kaiser RI. Gas-Phase Formation of 1-Methylcyclopropene and 3-Methylcyclopropene via the Reaction of the Methylidyne Radical (CH; X 2Π) with Propylene (CH 3CHCH 2; X 1A'). J Phys Chem A 2019; 123:10543-10555. [PMID: 31718184 DOI: 10.1021/acs.jpca.9b09815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The crossed molecular beam reactions of the methylidyne radical (CH; X2Π) with propylene (CH3CHCH2; X1A') along with (partially) substituted reactants were conducted at collision energies of 19.3 kJ mol-1. Combining our experimental data with ab initio electronic structure and statistical calculations, the methylidyne radical is revealed to add barrierlessly to the carbon-carbon double bond of propylene reactant resulting in a cyclic doublet C4H7 intermediate with a lifetime longer than its rotation period. These adducts undergo a nonstatistical unimolecular decomposition via atomic hydrogen loss through tight exit transition states forming the cyclic products 1-methylcyclopropene and 3-methylcyclopropene with overall reaction exoergicities of 168 ± 25 kJ mol-1. These C4H6 isomers are predicted to exist even in low-temperature environments such as cold molecular clouds like TMC-1, since the reaction is barrierless and exoergic, all transition states are below the energy of the separated reactants, and both the methylidyne radical (CH; X2Π) and propylene reactant were detected in cold molecular clouds such as TMC-1.
Collapse
Affiliation(s)
- Chao He
- Department of Chemistry , University of Hawai'i at Manoa , Honolulu , Hawaii 96822 , United States
| | - Aaron M Thomas
- Department of Chemistry , University of Hawai'i at Manoa , Honolulu , Hawaii 96822 , United States
| | - Galiya R Galimova
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , United States.,Samara National Research University , Samara 443086 , Russia
| | - Alexander M Mebel
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , United States
| | - Ralf I Kaiser
- Department of Chemistry , University of Hawai'i at Manoa , Honolulu , Hawaii 96822 , United States
| |
Collapse
|
14
|
Caster KL, Donnellan ZN, Selby TM, Goulay F. Kinetic Investigations of the CH (X2Π) Radical Reaction with Cyclopentadiene. J Phys Chem A 2019; 123:5692-5703. [PMID: 31194547 DOI: 10.1021/acs.jpca.9b03813] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kacee L. Caster
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Zachery N. Donnellan
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Talitha M. Selby
- Department of Mathematics and Natural Sciences, University of Wisconsin—Milwaukee, West Bend, Wisconsin 53095, United States
| | - F. Goulay
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
15
|
Abplanalp MJ, Góbi S, Kaiser RI. On the formation and the isomer specific detection of methylacetylene (CH 3CCH), propene (CH 3CHCH 2), cyclopropane (c-C 3H 6), vinylacetylene (CH 2CHCCH), and 1,3-butadiene (CH 2CHCHCH 2) from interstellar methane ice analogues. Phys Chem Chem Phys 2019; 21:5378-5393. [PMID: 30221272 DOI: 10.1039/c8cp03921f] [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
Pure methane (CH4) ices processed by energetic electrons under ultra-high vacuum conditions to simulate secondary electrons formed via galactic cosmic rays (GCRs) penetrating interstellar ice mantles have been shown to produce an array of complex hydrocarbons with the general formulae: CnH2n+2 (n = 4-8), CnH2n (n = 3-9), CnH2n-2 (n = 3-9), CnH2n-4 (n = 4-9), and CnH2n-6 (n = 6-7). By monitoring the in situ chemical evolution of the ice combined with temperature programmed desorption (TPD) studies and tunable single photon ionization coupled to a reflectron time-of-flight mass spectrometer, specific isomers of C3H4, C3H6, C4H4, and C4H6 were probed. These experiments confirmed the synthesis of methylacetylene (CH3CCH), propene (CH3CHCH2), cyclopropane (c-C3H6), vinylacetylene (CH2CHCCH), 1-butyne (HCCC2H5), 2-butyne (CH3CCCH3), 1,2-butadiene (H2CCCH(CH3)), and 1,3-butadiene (CH2CHCHCH2) with yields of 2.17 ± 0.95 × 10-4, 3.7 ± 1.5 × 10-3, 1.23 ± 0.77 × 10-4, 1.28 ± 0.65 × 10-4, 4.01 ± 1.98 × 10-5, 1.97 ± 0.98 × 10-4, 1.90 ± 0.84 × 10-5, and 1.41 ± 0.72 × 10-4 molecules eV-1, respectively. Mechanistic studies exploring the formation routes of methylacetylene, propene, and vinylacetylene were also conducted, and revealed the additional formation of the 1,2,3-butatriene isomer. Several of the above isomers, methylacetylene, propene, vinylacetylene, and 1,3-butadiene, have repeatedly been shown to be important precursors in the formation of polycyclic aromatic hydrocarbons (PAHs), but until now their interstellar synthesis has remained elusive.
Collapse
Affiliation(s)
- Matthew J Abplanalp
- W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, HI 96822, USA.
| | | | | |
Collapse
|
16
|
Wang W, Feng W, Wang W, Li P. Theoretical Investigations on the Reactivity of Methylidyne Radical toward 2,3,7,8-Tetrachlorodibenzo- p-Dioxin: A DFT and Molecular Dynamics Study. Molecules 2018; 23:E2685. [PMID: 30340385 PMCID: PMC6222546 DOI: 10.3390/molecules23102685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 12/22/2022] Open
Abstract
To explore the potential reactivity of the methylidyne radical (CH) toward 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the reaction mechanism between them has been systematically investigated employing the density functional theory (DFT) and ab initio molecular dynamics simulations. The relevant thermodynamic and kinetic parameters in the possible reaction pathways have been discussed as well as the IR spectra and hyperfine coupling constants (hfcc's) of the major products. Different from the reaction of the CH radical with 2,3,7,8-tetrachlorodibenzofuran, CH radical can attack all the C-C bonds of TCDD to form an initial intermediate barrierlessly via the cycloaddition mechanism. After then, the introduced C-H bond can be further inserted into the C-C bond of TCDD, resulting in the formation of a seven-membered ring structure. The whole reactions are favorable thermodynamically and kinetically. Moreover, the major products have been verified by ab initio molecular dynamics simulations. The distinct IR spectra and hyperfine coupling constants of the major products can provide some help for their experimental detection and identification. In addition, the reactivity of the CH radical toward the F- and Br-substituted TCDDs has also been investigated. Hopefully, the present findings can provide new insights into the reactivity of the CH radical in the transformation of TCDD-like dioxins.
Collapse
Affiliation(s)
- Weihua Wang
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| | - Wenling Feng
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| | - Wenliang Wang
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| | - Ping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, China.
| |
Collapse
|
17
|
Wei W, Wang W, Xu K, Feng W, Li X, Li P. Theoretical insights into the reaction mechanisms between 2,3,7,8-tetrachlorodibenzofuran and the methylidyne radical. RSC Adv 2018; 8:21150-21163. [PMID: 35539902 PMCID: PMC9080895 DOI: 10.1039/c8ra03046d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/03/2018] [Indexed: 11/21/2022] Open
Abstract
To explore the potential role of the methylidyne radical (CH) in the transformation of 2,3,7,8-tetrachlorodibenzofuran (TCDF), in this study, the detailed reaction mechanisms between TCDF and CH radical have been systematically investigated employing the B3LYP method of density functional theory (DFT) in combination with the atoms in molecules (AIM) theory and ab initio molecular dynamics. It was found that the title reaction is a multi-channel reaction, i.e., the CH radical can attack the C-X (X = C, Cl, H, O) bonds of TCDF via the insertion modes, resulting in the formation of 13 products. Thermodynamically, the whole reaction processes are exothermic and spontaneous since all the enthalpy and Gibbs free energy changes are negative values in the formation processes. Moreover, the thermodynamic stability of the products is controlled by the distribution of the single unpaired electron. Kinetically, the most favorable reaction channel is the insertion of the CH radical into the C-C bond except for the C atoms attached to the chlorine atom. Moreover, the dominant products have been further confirmed by the molecular dynamics. Meanwhile, the IR spectra and hyperfine coupling constants of the dominant products have been investigated to provide helpful information for their identification experimentally. In addition, the reactivity of the CH radical toward the F- and Br-substituted TCDFs has also been investigated. Expectedly, the present findings can enable us to better understand the reactivity of the CH radical toward organic pollutants analogous to TCDF in the atmosphere.
Collapse
Affiliation(s)
- Wenjing Wei
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Weihua Wang
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Kaining Xu
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Wenling Feng
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Xiaoping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| | - Ping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical Engineering, Qufu Normal University Qufu 273165 P. R. China
| |
Collapse
|
18
|
Broderick BM, Suas-David N, Dias N, Suits AG. Isomer-specific detection in the UV photodissociation of the propargyl radical by chirped-pulse mm-wave spectroscopy in a pulsed quasi-uniform flow. Phys Chem Chem Phys 2018; 20:5517-5529. [PMID: 29165455 DOI: 10.1039/c7cp06211g] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Isomer-specific detection and product branching fractions in the UV photodissociation of the propargyl radical is achieved through the use of chirped-pulse Fourier-transform mm-wave spectroscopy in a pulsed quasi-uniform flow (CPUF). Propargyl radicals are produced in the 193 nm photodissociation of 1,2-butadiene. Absorption of a second photon leads to H atom elimination giving three possible C3H2 isomers: singlets cyclopropenylidene (c-C3H2) and propadienylidene (l-C3H2), and triplet propargylene (3HCCCH). The singlet products and their appearance kinetics in the flow are directly determined by rotational spectroscopy, but due to the negligible dipole moment of propargylene, it is not directly monitored. However, we exploit the time-dependent kinetics of H-atom catalyzed isomerization to infer the branching to propargylene as well. We obtain the overall branching among H loss channels to be 2.9% (+1.1/-0.5) l-C3H2 + H, 16.8% (+3.2/-1.3) c-C3H2 + H, and 80.2 (+1.8/-4.2) 3HCCCH + H. Our findings are qualitatively consistent with earlier RRKM calculations in that the major channel in the photodissociation of the propargyl radical at 193 nm is to 3HCCCH + H; however, a greater contribution to the energetically most favorable isomer, c-C3H2 + H is observed in this work. We do not detect the predicted HCCC + H2 channel, but place an upper bound on its yield of 1%.
Collapse
Affiliation(s)
- Bernadette M Broderick
- Department of Chemistry, University of Missouri, 601 S. College Ave, Columbia MO 65211, USA.
| | | | | | | |
Collapse
|
19
|
Agúndez M, Cernicharo J, Quintana-Lacaci G, Castro-Carrizo A, Velilla Prieto L, Marcelino N, Guélin M, Joblin C, Martín-Gago JA, Gottlieb CA, Patel NA, McCarthy MC. The growth of carbon chains in IRC +10216 mapped with ALMA. ASTRONOMY AND ASTROPHYSICS 2017; 601:A4. [PMID: 28469283 PMCID: PMC5405872 DOI: 10.1051/0004-6361/201630274] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Linear carbon chains are common in various types of astronomical molecular sources. Possible formation mechanisms involve both bottom-up and top-down routes. We have carried out a combined observational and modeling study of the formation of carbon chains in the C-star envelope IRC +10216, where the polymerization of acetylene and hydrogen cyanide induced by ultraviolet photons can drive the formation of linear carbon chains of increasing length. We have used ALMA to map the emission of λ 3 mm rotational lines of the hydrocarbon radicals C2H, C4H, and C6H, and the CN-containing species CN, C3N, HC3N, and HC5N with an angular resolution of ~1″. The spatial distribution of all these species is a hollow, 5-10″ wide, spherical shell located at a radius of 10-20″ from the star, with no appreciable emission close to the star. Our observations resolve the broad shell of carbon chains into thinner sub-shells which are 1-2″ wide and not fully concentric, indicating that the mass loss process has been discontinuous and not fully isotropic. The radial distributions of the species mapped reveal subtle differences: while the hydrocarbon radicals have very similar radial distributions, the CN-containing species show more diverse distributions, with HC3N appearing earlier in the expansion and the radical CN extending later than the rest of the species. The observed morphology can be rationalized by a chemical model in which the growth of polyynes is mainly produced by rapid gas-phase chemical reactions of C2H and C4H radicals with unsaturated hydrocarbons, while cyanopolyynes are mainly formed from polyynes in gas-phase reactions with CN and C3N radicals.
Collapse
Affiliation(s)
- M Agúndez
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - J Cernicharo
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - G Quintana-Lacaci
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - A Castro-Carrizo
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St. Martin d'Héres, France
| | - L Velilla Prieto
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - N Marcelino
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - M Guélin
- Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 St. Martin d'Héres, France
| | - C Joblin
- Université de Toulouse, UPS-OMS, IRAP, 31000 Toulouse, France
- CNRS, IRAP, 9 Av. Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
| | - J A Martín-Gago
- Instituto de Ciencia de Materiales de Madrid, CSIC, C/ Sor Juana Inés de la Cruz 3, 28049 Cantoblanco, Spain
| | - C A Gottlieb
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - N A Patel
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
| | - M C McCarthy
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
20
|
Wang Y, Tang Y, Shao Y. Theoretical investigation on the reaction of Methylidyne Radical (CH) with acetaldehyde (CH 3 CHO). COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.01.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
21
|
Ribeiro JM, Mebel AM. Reaction mechanism and product branching ratios of the CH + C3H4 reactions: a theoretical study. Phys Chem Chem Phys 2017; 19:14543-14554. [PMID: 28537287 DOI: 10.1039/c7cp01873h] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Joao Marcelo Ribeiro
- Department of Chemistry and Biochemistry, Florida International University, Miami, FL 33199, USA.
| | | |
Collapse
|
22
|
Hickson KM, Wakelam V, Loison JC. Methylacetylene (CH3CCH) and propene (C3H6) formation in cold dense clouds: A case of dust grain chemistry. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molap.2016.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
23
|
Ribeiro JM, Mebel AM. Reaction Mechanism and Product Branching Ratios of the CH + C3H6 Reaction: A Theoretical Study. J Phys Chem A 2016; 120:1800-12. [DOI: 10.1021/acs.jpca.5b12588] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joao Marcelo Ribeiro
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Alexander M. Mebel
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| |
Collapse
|
24
|
Trevitt AJ, Goulay F. Insights into gas-phase reaction mechanisms of small carbon radicals using isomer-resolved product detection. Phys Chem Chem Phys 2016; 18:5867-82. [DOI: 10.1039/c5cp06389b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase radical reactions of CN and CH with small hydrocarbons are overviewed with emphasis on isomer-resolved product detection.
Collapse
Affiliation(s)
- Adam J. Trevitt
- School of Chemistry
- University of Wollongong
- Wollongong
- Australia
| | - Fabien Goulay
- Department of Chemistry
- West Virginia University
- Morgantown
- USA
| |
Collapse
|
25
|
Sun YL, Huang WJ, Lee SH. Formation of C3H2, C5H2, C7H2, and C9H2 from reactions of CH, C3H, C5H, and C7H radicals with C2H2. Phys Chem Chem Phys 2016; 18:2120-9. [DOI: 10.1039/c5cp06072a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A three-dimensional velocity distribution contour of C2n+1H2 produced from the reaction of C2n−1H (n = 1–4) with C2H2 in crossed molecular beams.
Collapse
Affiliation(s)
- Yi-Lun Sun
- National Synchrotron Radiation Research Center (NSRRC)
- Hsinchu 30076
- Taiwan
| | - Wen-Jian Huang
- National Synchrotron Radiation Research Center (NSRRC)
- Hsinchu 30076
- Taiwan
| | - Shih-Huang Lee
- National Synchrotron Radiation Research Center (NSRRC)
- Hsinchu 30076
- Taiwan
| |
Collapse
|
26
|
Zeng T, Wang H, Lu Y, Xie Y, Wang H, Schaefer HF, Ananth N, Hoffmann R. Tuning spin-states of carbynes and silylynes: a long jump with one leg. J Am Chem Soc 2014; 136:13388-98. [PMID: 25152996 DOI: 10.1021/ja5073993] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The challenge motivating this paper is to induce, by chemical substitution, a silylyne, SiR, or a congeneric carbyne, CR, to adopt the high-spin quartet rather than the low-spin doublet as its ground state. The difficulty is seen in the preference for the doublet of the parent SiH (doublet-quartet energy difference ∼39 kcal/mol, favoring the doublet) or CH (∼17 kcal/mol). Strategies for having high-spin ground state parallel those for silylenes and carbenes: greater electropositivity (σ-donation) and π-acceptance of the single substituent favor the high-spin state. The electronegativity trend can be understood from an ions in molecules way of thinking already present in the literature in the works of Boldyrev and Simons, and of Mavridis and Harrison; i.e., the quartet ground state spin of some CR/SiR species is largely determined by the ground state spin of C(-)/Si(-). In this study, we provide a diabatization analysis that solidly confirms the ions in molecules picture and explains the difference in the equilibrium internuclear distances for the two spin states. In general, electronegativity dominates the ordering of spin states. π-Acceptors also help to lower the quartet state energy of the many carbynes (silylynes) examined, whose range of doublet-quartet differences calculated is impressive, 120 (100) kcal/mol. The qualitative understanding gained leads to the prediction of some quartet-ground state carbynes (CMgH, CAlH2, CZnH, CSiH3, CSiF3, etc.) and a smaller number of silylynes (SiMgH, SiMgF, SiBeH, etc.). A beginning is made on the energetics of approach geometries of the fragments in the highly exoergic dimerization of CH to acetylene; it should proceed for the ground state doublet CH through C2h-like trajectories, with no activation energy.
Collapse
Affiliation(s)
- Tao Zeng
- Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Lockyear JF, Welz O, Savee JD, Goulay F, Trevitt AJ, Taatjes CA, Osborn DL, Leone SR. Isomer Specific Product Detection in the Reaction of CH with Acrolein. J Phys Chem A 2013; 117:11013-26. [DOI: 10.1021/jp407428v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Jessica F. Lockyear
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Oliver Welz
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - John D. Savee
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - Fabien Goulay
- Department
of Chemistry, West Virginia University, Morgantown, West Virginia, 26506, United States
| | - Adam J. Trevitt
- School
of Chemistry, University of Wollongong, Wollongong, NSW 2522 Australia
| | - Craig A. Taatjes
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - David L. Osborn
- Combustion
Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California, 94551, United States
| | - Stephen R. Leone
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
- Departments
of Chemistry and Physics, University of California, Berkeley, California 94720, United States
| |
Collapse
|
28
|
Trevitt AJ, Prendergast MB, Goulay F, Savee JD, Osborn DL, Taatjes CA, Leone SR. Product Branching Fractions of the CH + Propene Reaction from Synchrotron Photoionization Mass Spectrometry. J Phys Chem A 2013; 117:6450-7. [DOI: 10.1021/jp404965k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adam J. Trevitt
- School of
Chemistry, University of Wollongong, NSW
2522 Australia
| | | | - Fabien Goulay
- Department
of Chemistry, West Virginia University,
Morgantown, West Virginia
26506, United States
| | - John D. Savee
- Combustion
Research Facility,
Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551, United States
| | - David L. Osborn
- Combustion
Research Facility,
Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551, United States
| | - Craig A. Taatjes
- Combustion
Research Facility,
Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551, United States
| | - Stephen R. Leone
- Departments of Chemistry and Physics,
and Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720, United States
| |
Collapse
|
29
|
Danovich D, Bino A, Shaik S. Formation of Carbon-Carbon Triply Bonded Molecules from Two Free Carbyne Radicals via a Conical Intersection. J Phys Chem Lett 2013; 4:58-64. [PMID: 26291212 DOI: 10.1021/jz3016765] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The recent proposal (Bogoslavsky, B.; Levy, O.; Kotlyar, A.; Salem, M.; Gelman, F.; Bino, A. Angew. Chem., Int. Ed.2012, 51, 90-94) that metallo-alkylidyne complexes decompose in aqueous solution and give rise to free carbynes, which couple to yield acetylenes, is examined here theoretically. On the basis of the known marker reactions of carbynes in the doublet and quartet state, it is concluded that most of the reactivity patterns observed in the Bino experiment arose from quartet carbynes. Indeed, theory shows that quartet carbynes can be funneled to acetylene via a conical intersection. Moreover, many of the minor products are also identified as markers of the quartet carbynes. Carbynes formation in their doublet state is a minor channel that branches from the conical intersection and leads to the formation of dienes and olefins in the Bino experiment. Thus, we show that conical intersections are important also in thermally initiated reactions. Coupled to the experimental approach, the study opens a window to studies of carbynes under mild conditions.
Collapse
Affiliation(s)
- David Danovich
- †Institute of Chemistry and ‡The Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904 Jerusalem, Israel
| | - Avi Bino
- †Institute of Chemistry and ‡The Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904 Jerusalem, Israel
| | - Sason Shaik
- †Institute of Chemistry and ‡The Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, 91904 Jerusalem, Israel
| |
Collapse
|
30
|
Levy O, Musa S, Bino A. Formation of an alkyne during degradation of metal–alkylidyne complexes. Dalton Trans 2013; 42:12248-51. [DOI: 10.1039/c3dt50921d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
31
|
Goulay F, Trevitt AJ, Savee JD, Bouwman J, Osborn DL, Taatjes CA, Wilson KR, Leone SR. Product Detection of the CH Radical Reaction with Acetaldehyde. J Phys Chem A 2012; 116:6091-106. [DOI: 10.1021/jp2113126] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Adam J. Trevitt
- School of Chemistry, University of Wollongong, Wollongong, NSW 2522, Australia
| | - John D. Savee
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551,
United States
| | | | - David L. Osborn
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551,
United States
| | - Craig A. Taatjes
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551,
United States
| | - Kevin R. Wilson
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Stephen R. Leone
- Chemical
Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| |
Collapse
|
32
|
Zhang F, Maksyutenko P, Kaiser RI. Chemical dynamics of the CH(X2Π) + C2H4(X1A1g), CH(X2Π) + C2D4(X1A1g), and CD(X2Π) + C2H4(X1A1g) reactions studied under single collision conditions. Phys Chem Chem Phys 2012; 14:529-37. [PMID: 22108533 DOI: 10.1039/c1cp22350j] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Fangtong Zhang
- Department of Chemistry, University of Hawai'i at Mānoa, Honolulu, Hawaii 96822, USA
| | | | | |
Collapse
|
33
|
Kaiser RI, Gu X, Zhang F, Maksyutenko P. Crossed beam reactions of methylidyne [CH(X2Π)] with D2-acetylene [C2D2(X1Σg+)] and of D1-methylidyne [CD(X2Π)] with acetylene [C2H2(X1Σg+)]. Phys Chem Chem Phys 2012; 14:575-88. [DOI: 10.1039/c1cp22635e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
34
|
Blitz MA, Seakins PW. Laboratory studies of photochemistry and gas phase radical reaction kinetics relevant to planetary atmospheres. Chem Soc Rev 2012; 41:6318-47. [DOI: 10.1039/c2cs35204d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
35
|
Blitz MA, Talbi D, Seakins PW, Smith IWM. Rate Constants and Branching Ratios for the Reaction of CH Radicals with NH3: A Combined Experimental and Theoretical Study. J Phys Chem A 2011; 116:5877-85. [DOI: 10.1021/jp209383t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Mark A. Blitz
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, United Kingdom LS2 9JT
| | - Dahbia Talbi
- LUPM, Université de Montpelier II, CNRS, Place Eugène Bataillon, 34095 Montpelier cedex 05, France
| | - Paul W. Seakins
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, United Kingdom LS2 9JT
| | - Ian W. M. Smith
- LUPM, Université de Montpelier II, CNRS, Place Eugène Bataillon, 34095 Montpelier cedex 05, France
- University Chemical Laboratories, Lensfield Road, Cambridge, United Kingdom CB2 1EW
| |
Collapse
|
36
|
Jamal A, Mebel AM. An ab initio/RRKM study of the reaction mechanism and product branching ratios of the reactions of ethynyl radical with 1,2-butadiene. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.10.064] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
37
|
Theoretical mechanistic study of the reaction of the methylidyne radical with methylacetylene. J Mol Model 2011; 17:3173-81. [DOI: 10.1007/s00894-011-0979-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Accepted: 01/18/2011] [Indexed: 11/27/2022]
|
38
|
Trevitt AJ, Soorkia S, Savee JD, Selby TS, Osborn DL, Taatjes CA, Leone SR. Branching Fractions of the CN + C3H6 Reaction Using Synchrotron Photoionization Mass Spectrometry: Evidence for the 3-Cyanopropene Product. J Phys Chem A 2011; 115:13467-73. [DOI: 10.1021/jp208496r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Adam J. Trevitt
- School of Chemistry, University of Wollongong, NSW 2522, Australia
| | - Satchin Soorkia
- Departments of Chemistry and Physics, University of California, Berkeley, California 94720, United States
| | - John D. Savee
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551, United States
| | - Talitha S. Selby
- Department of Chemistry, University of Wisconsin—Washington County, West Bend, Wisconsin 53095, United States
| | - David L. Osborn
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551, United States
| | - Craig A. Taatjes
- Combustion Research Facility, Mail Stop 9055, Sandia National Laboratories, Livermore, California 94551, United States
| | - Stephen R. Leone
- Departments of Chemistry and Physics, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| |
Collapse
|
39
|
Bogoslavsky B, Levy O, Kotlyar A, Salem M, Gelman F, Bino A. Do Carbyne Radicals Really Exist in Aqueous Solution? Angew Chem Int Ed Engl 2011; 51:90-4. [DOI: 10.1002/anie.201103652] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2011] [Revised: 09/04/2011] [Indexed: 11/11/2022]
|
40
|
Bogoslavsky B, Levy O, Kotlyar A, Salem M, Gelman F, Bino A. Do Carbyne Radicals Really Exist in Aqueous Solution? Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201103652] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
41
|
Maksyutenko P, Zhang F, Gu X, Kaiser RI. A crossed molecular beam study on the reaction of methylidyne radicals [CH(X2Π)] with acetylene [C2H2(X1Σg+)]—competing C3H2+ H and C3H + H2channels. Phys Chem Chem Phys 2011; 13:240-52. [DOI: 10.1039/c0cp01529f] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
42
|
Abstract
Polycyclic aromatic hydrocarbons and related species have been suggested to play a key role in the astrochemical evolution of the interstellar medium, but the formation mechanism of even their simplest building block--the aromatic benzene molecule--has remained elusive for decades. Here we demonstrate in crossed molecular beam experiments combined with electronic structure and statistical calculations that benzene (C(6)H(6)) can be synthesized via the barrierless, exoergic reaction of the ethynyl radical and 1,3-butadiene, C(2)H + H(2)CCHCHCH(2) → C(6)H(6) + H, under single collision conditions. This reaction portrays the simplest representative of a reaction class in which aromatic molecules with a benzene core can be formed from acyclic precursors via barrierless reactions of ethynyl radicals with substituted 1,3-butadiene molecules. Unique gas-grain astrochemical models imply that this low-temperature route controls the synthesis of the very first aromatic ring from acyclic precursors in cold molecular clouds, such as in the Taurus Molecular Cloud. Rapid, subsequent barrierless reactions of benzene with ethynyl radicals can lead to naphthalene-like structures thus effectively propagating the ethynyl-radical mediated formation of aromatic molecules in the interstellar medium.
Collapse
|
43
|
Li Y, Liu HL, Zhou ZJ, Huang XR, Sun CC. Reaction Mechanism of CH + C3H6: A Theoretical Study. J Phys Chem A 2010; 114:9496-506. [DOI: 10.1021/jp102029w] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yan Li
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People’s Republic of China
| | - Hui-ling Liu
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People’s Republic of China
| | - Zhong-Jun Zhou
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People’s Republic of China
| | - Xu-ri Huang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People’s Republic of China
| | - Chia-chung Sun
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People’s Republic of China
| |
Collapse
|
44
|
Soorkia S, Taatjes CA, Osborn DL, Selby TM, Trevitt AJ, Wilson KR, Leone SR. Direct detection of pyridine formation by the reaction of CH (CD) with pyrrole: a ring expansion reaction. Phys Chem Chem Phys 2010; 12:8750-8. [DOI: 10.1039/c002135k] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
45
|
|
46
|
Blitz MA, Seakins PW, Smith IWM. An experimental confirmation of the products of the reaction between CN radicals and NH3. Phys Chem Chem Phys 2009; 11:10824-6. [DOI: 10.1039/b917734e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|