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Jaddi A, Marakchi K, Zanchet A, García-Vela A. A high-level ab initio study of the photodissociation of acetaldehyde. J Chem Phys 2024; 160:224309. [PMID: 38874103 DOI: 10.1063/5.0207362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 05/23/2024] [Indexed: 06/15/2024] Open
Abstract
Acetaldehyde is a very relevant atmospheric species whose photodissociation has been extensively studied in the first absorption band both experimentally and theoretically. Very few works have been reported on acetaldehyde photodissociation at higher excitation energies. In this work, the photodissociation dynamics of acetaldehyde is investigated by means of high-level multireference configuration interaction ab initio calculations. Five different fragmentation pathways of acetaldehyde are explored by calculating the potential-energy curves of the ground and several excited electronic states along the corresponding dissociating bond distances. The excitation energy range covered in the study is up to 10 eV, nearly the ionization energy of acetaldehyde. We intend to rationalize the available experimental results and, in particular, to elucidate why some of the studied fragmentation pathways are experimentally observed in the different excitation energy regions and some others are not. Based on the shape of the calculated potential curves, we are able to explain the main findings of the available experiments, also suggesting possible dynamical dissociation mechanisms in the different energy regions. Thus, the reported potential curves are envisioned as a useful tool to interpret the currently available experiments as well as future ones on acetaldehyde photodissociation at excitation wavelengths in the range studied here.
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Affiliation(s)
- A Jaddi
- Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, LS3MN2E/CERNE2D, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain
| | - K Marakchi
- Laboratory of Spectroscopy, Molecular Modeling, Materials, Nanomaterials, Water and Environment, LS3MN2E/CERNE2D, Faculty of Sciences, Mohammed V University in Rabat, Rabat, Morocco
| | - A Zanchet
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain
| | - A García-Vela
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain
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2
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Zasimov PV, Sanochkina EV, Feldman VI. Radiation-induced transformations of acetaldehyde molecules at cryogenic temperatures: a matrix isolation study. Phys Chem Chem Phys 2021; 24:419-432. [PMID: 34897322 DOI: 10.1039/d1cp03999g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Acetaldehyde is one of the key small organic molecules involved in astrochemical and atmospheric processes occurring under the action of ionizing and UV radiation. While the UV photochemistry of acetaldehyde is well studied, little is known about the mechanism of processes induced by high-energy radiation. This paper reports the first systematic study on the chemical transformations of CH3CHO molecules resulting from X-ray irradiation under the conditions of matrix isolation in different solid noble gases (Ne, Ar, Kr, and Xe) at 5 K. CO, CH4, H2CCO, H2CCO-H2, C2H2⋯H2O, CH2CHOH, CH3CO˙, CH3˙, HCCO˙, and CCO were identified as the main radiolysis products. The dominant pathway of acetaldehyde degradation involves C-C bond cleavage leading to the formation of carbon monoxide and methane. The second important channel is dehydrogenation resulting in the formation of ketene, a potentially highly reactive species. It was found that the matrix significantly affected both the decomposition efficiency and distribution of the reaction channels. Based on these observations, it was suggested that the formation of the methyl radical as well as vinyl alcohol and the C2H2⋯H2O complex presumably included a significant contribution of ionic pathways. The decomposition of acetyl radicals under photolysis with visible light leading to the CH3˙-CO radical-molecule pair was observed in all matrices, while the recovery of CH3CO˙ in the dark at 5 K was found only in Xe. This finding represents a prominent example of matrix-dependent chemical dynamics (probably, involving tunnelling), which deserves further theoretical studies. Probable mechanisms of acetaldehyde radiolysis and their implications for astrochemistry, atmospheric chemistry and low-temperature chemistry are discussed.
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Affiliation(s)
- Pavel V Zasimov
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
| | | | - Vladimir I Feldman
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia.
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3
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Kleimeier NF, Turner AM, Fortenberry RC, Kaiser RI. On the Formation of the Popcorn Flavorant 2,3-Butanedione (CH 3 COCOCH 3 ) in Acetaldehyde-Containing Interstellar Ices. Chemphyschem 2020; 21:1531-1540. [PMID: 32458552 DOI: 10.1002/cphc.202000116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/25/2020] [Indexed: 11/06/2022]
Abstract
Acetaldehyde (CH3 CHO) is ubiquitous throughout the interstellar medium and has been observed in cold molecular clouds, star forming regions, and in meteorites such as Murchison. As the simplest methyl-bearing aldehyde, acetaldehyde constitutes a critical precursor to prebiotic molecules such as the sugar deoxyribose and amino acids via the Strecker synthesis. In this study, we reveal the first laboratory detection of 2,3-butanedione (diacetyl, CH3 COCOCH3 ) - a butter and popcorn flavorant - synthesized within acetaldehyde-based interstellar analog ices exposed to ionizing radiation at 5 K. Detailed isotopic substitution experiments combined with tunable vacuum ultraviolet (VUV) photoionization of the subliming molecules demonstrate that 2,3-butanedione is formed predominantly via the barrier-less radical-radical reaction of two acetyl radicals (CH3 ĊO). These processes are of fundamental importance for a detailed understanding of how complex organic molecules (COMs) are synthesized in deep space thus constraining the molecular structures and complexity of molecules forming in extraterrestrial ices containing acetaldehyde through a vigorous galactic cosmic ray driven non-equilibrium chemistry.
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Affiliation(s)
- N Fabian Kleimeier
- Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawai'i at Manoa 2545 McCarthy Mall, Honolulu, HI, 96822, USA
| | - Andrew M Turner
- Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawai'i at Manoa 2545 McCarthy Mall, Honolulu, HI, 96822, USA
| | - Ryan C Fortenberry
- Department of Chemistry & Biochemistry, University of Mississippi, 322 Coulter Hall, University, MS, 38677-1848, USA
| | - Ralf I Kaiser
- Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawai'i at Manoa 2545 McCarthy Mall, Honolulu, HI, 96822, USA
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Sullivan EN, Saric S, Neumark DM. Photodissociation of iso-propoxy (i-C 3H 7O) radical at 248 nm. Phys Chem Chem Phys 2020; 22:17738-17748. [DOI: 10.1039/d0cp02493g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photodissociation of the i-C3H7O radical is investigated using fast beam photofragment translational spectroscopy.
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Affiliation(s)
- Erin N. Sullivan
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
| | - Steven Saric
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
| | - Daniel M. Neumark
- Department of Chemistry
- University of California
- Berkeley
- USA
- Chemical Sciences Division
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5
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Harrison AW, Kharazmi A, Shaw MF, Quinn MS, Lee KLK, Nauta K, Rowell KN, Jordan MJT, Kable SH. Dynamics and quantum yields of H2 + CH2CO as a primary photolysis channel in CH3CHO. Phys Chem Chem Phys 2019; 21:14284-14295. [DOI: 10.1039/c8cp06412a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new ketene + H2 channel in CH3CHO photolysis is not modelled by quasi-classical trajectories over the transition state.
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Affiliation(s)
| | - Alireza Kharazmi
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | | | | | - K. L. Kelvin Lee
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | - Klaas Nauta
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | - Keiran N. Rowell
- School of Chemistry, University of New South Wales
- Sydney
- Australia
| | | | - Scott H. Kable
- School of Chemistry, University of New South Wales
- Sydney
- Australia
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Ashfold MNR, Ingle RA, Karsili TNV, Zhang J. Photoinduced C–H bond fission in prototypical organic molecules and radicals. Phys Chem Chem Phys 2019; 21:13880-13901. [DOI: 10.1039/c8cp07454b] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We survey and assess current knowledge regarding the primary photochemistry of hydrocarbon molecules and radicals.
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Affiliation(s)
| | | | | | - Jingsong Zhang
- Department of Chemistry
- University of California at Riverside
- Riverside
- USA
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7
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Han YC. Quasiclassical trajectory calculations of CD3CHO dissociation to CD2H + DCO on a global potential energy surface. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1142/s0219633618500475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We present a quasiclassical trajectory study of the photodissociation of CD3CHO based on a global ab initio-based potential energy surface. Calculations are performed at the total energy corresponding to the photolysis wavelength of 280[Formula: see text]nm. In addition to the major radical and molecular products, CD[Formula: see text] and CD3H [Formula: see text] CO, respectively, this paper focuses on the unusual radical channel CD2H [Formula: see text] DCO, which requires a D/H exchange process before the conventional C–C bond cleavage. Five D/H exchange mechanisms are reported, which are related to the isomerizations from acetaldehyde to vinyl alcohol and back, to oxirane and back, and to the intermediate (CD–CHD–OD) and back. These D/H exchange mechanisms are in good agreement with the experimental findings [Heazlewood BR, Maccarone AT, Andrews DU, Osborn DL, Harding LB, Klippenstein SJ, Jordan MJT, Kable SH, Nat Chem 3:443, 2011].
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Affiliation(s)
- Yong-Chang Han
- Department of Physics, Dalian University of Technology, Dalian 116024, P. R. China
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Vincent JC, Muuronen M, Pearce KC, Mohanam LN, Tapavicza E, Furche F. That Little Extra Kick: Nonadiabatic Effects in Acetaldehyde Photodissociation. J Phys Chem Lett 2016; 7:4185-4190. [PMID: 27704839 DOI: 10.1021/acs.jpclett.6b02037] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The effect of nonadiabatic transitions on branching ratios, kinetic and internal energy distribution of fragments, and reaction mechanisms observed in acetaldehyde photodissociation is investigated by nonadiabatic molecular dynamics (NAMD) simulations using time-dependent hybrid density functional theory and Tully surface hopping. Homolytic bond breaking is approximately captured by allowing spin symmetry to break. The NAMD simulations reveal that nonadiabatic transitions selectively enhance the kinetic energy of certain internal degrees of freedom within approximately 50 fs. Branching ratios from NAMD and conventional "hot" Born-Oppenheimer molecular dynamics (BOMD) are similar and qualitatively agree with experiment. However, as opposed to the BOMD simulations, NAMD captures the high-energy tail of the experimental kinetic energy distribution. The extra "kick" of the nuclei in the direction of the nonadiabatic coupling vector results from nonadiabatic transitions close to conical intersections. From a mechanistic perspective, the nonadiabatic effects favor asynchronous over synchronous fragmentation and tend to suppress roaming.
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Affiliation(s)
- Jordan C Vincent
- Department of Chemistry, University of California, Irvine , 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - Mikko Muuronen
- Department of Chemistry, University of California, Irvine , 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - Kirk C Pearce
- Department of Chemistry, University of California, Irvine , 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - Luke N Mohanam
- Department of Chemistry, University of California, Irvine , 1102 Natural Sciences II, Irvine, California 92697-2025, United States
| | - Enrico Tapavicza
- Department of Chemistry and Biochemistry, California State University, Long Beach , 1250 Bellflower Boulevard, Long Beach, California 90840-9507, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine , 1102 Natural Sciences II, Irvine, California 92697-2025, United States
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Zhang ZG, Chen ZC, Zhang CM, Jin YL, Zhang Q, Chen Y, Huang CS, Yang XM. Ion-Velocity Map Imaging Study of Photodissociation Dynamics of Acetaldehyde. CHINESE J CHEM PHYS 2014. [DOI: 10.1063/1674-0068/27/03/249-255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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10
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Lee SH, Chin CH, Chaudhuri C. Evidence for Synchronous Concerted Three-Body Dissociation of Propenal to C2H2+CO+H2. Chemphyschem 2011; 12:753-6. [DOI: 10.1002/cphc.201001091] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Indexed: 11/06/2022]
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11
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Lee SH, Chin CH, Chen WK, Huang WJ, Hsieh CC. Exploring the dynamics of reaction N(2D)+C2H4 with crossed molecular-beam experiments and quantum-chemical calculations. Phys Chem Chem Phys 2011; 13:8515-25. [DOI: 10.1039/c0cp02439b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Chaudhuri C, Lee SH. A complete look at the multi-channel dissociation of propenal photoexcited at 193 nm: branching ratios and distributions of kinetic energy. Phys Chem Chem Phys 2011; 13:7312-21. [DOI: 10.1039/c0cp01641a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Amaral GA, Arregui A, Rubio-Lago L, Rodríguez JD, Bañares L. Imaging the radical channel in acetaldehyde photodissociation: Competing mechanisms at energies close to the triplet exit barrier. J Chem Phys 2010; 133:064303. [DOI: 10.1063/1.3474993] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Shubert VA, Pratt ST. Photodissociation of Acetaldehyde and the Absolute Photoionization Cross Section of HCO. J Phys Chem A 2010; 114:11238-43. [DOI: 10.1021/jp102992b] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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