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Leng JG, Sharples TR, Fournier M, McKendrick KG, Craciunescu L, Paterson MJ, Costen ML. Inelastic scattering of NO(A 2Σ +) + CO 2: rotation-rotation pair-correlated differential cross sections. Faraday Discuss 2024. [PMID: 38757419 DOI: 10.1039/d3fd00162h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
A crossed beam velocity-map ion-imaging apparatus has been used to determine differential cross sections (DCSs) for the rotationally inelastic scattering of NO(A2Σ+, v = 0, j = 0.5) with CO2, as a function of both NO(A, v = 0, N') final state and the coincident final rotational energy of the CO2. The DCSs are dominated by forward-peaked scattering for all N', with significant rotational excitation of CO2, and a small backward scattered peak is also observed for all final N'. However, no rotational rainbow scattering is observed and there is no evidence for significant product rotational angular momentum polarization. New ab initio potential energy surface calculations at the PNO-CCSD(T)-F12b level of theory report strong attractive forces at long ranges with significant anisotropy relative to both NO and CO2. The absence of rotational rainbow scattering is consistent with removal of low-impact-parameter collisions via electronic quenching, in agreement with the literature quenching rates of NO(A) by CO2 and recent electronic structure calculations. We propose that high-impact-parameter collisions, that do not lead to quenching, experience strong anisotropic attractive forces that lead to significant rotational excitation in both NO and CO2, depolarizing product angular momentum while leading to forward and backward glory scattering.
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Affiliation(s)
- Joseph G Leng
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Thomas R Sharples
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Martin Fournier
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Kenneth G McKendrick
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Luca Craciunescu
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Martin J Paterson
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
| | - Matthew L Costen
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK.
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2
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Craciunescu L, Liane EM, Kirrander A, Paterson MJ. Excited-state van der Waals potential energy surfaces for the NO A2Σ+ + CO2X1Σg+ collision complex. J Chem Phys 2023; 159:124303. [PMID: 38127380 DOI: 10.1063/5.0165769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/06/2023] [Indexed: 12/23/2023] Open
Abstract
Excited state van der Waals (vdW) potential energy surfaces (PESs) of the NO A2Σ+ + CO2X1Σg+ system are thoroughly investigated using coupled cluster theory and complete active space perturbation theory to second order (CASPT2). First, it is shown that pair natural orbital coupled cluster singles and doubles with perturbative triples yields comparable accuracy compared to CCSD(T) for molecular properties and vdW-minima at a fraction of computational cost of the latter. Using this method in conjunction with highly diffuse basis sets and counterpoise correction for basis set superposition error, the PESs for different intermolecular orientations are investigated. These show numerous vdW-wells, interconnected for all geometries except one, with a maximum depth of up to 830 cm-1; considerably deeper than those on the ground state surface. Multi-reference effects are investigated with CASPT2 calculations. The long-range vdW-surfaces support recent experimental observations relating to rotational energy transfer due the anisotropy in the potentials.
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Affiliation(s)
- Luca Craciunescu
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, Scotland EH14 4AS, United Kingdom
| | - Eirik M Liane
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QZ Oxford, United Kingdom
| | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QZ Oxford, United Kingdom
| | - Martin J Paterson
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, Scotland EH14 4AS, United Kingdom
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3
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Bridgers A, Urquilla JA, Im J, Petit AS. Theoretical Study of the Photochemical Mechanisms of the Electronic Quenching of NO( A2Σ +) with CH 4, CH 3OH, and CO 2. J Phys Chem A 2023; 127:7228-7240. [PMID: 37552562 PMCID: PMC10476188 DOI: 10.1021/acs.jpca.3c03981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/15/2023] [Indexed: 08/10/2023]
Abstract
The electronic quenching of NO(A2Σ+) with molecular partners occurs through complex non-adiabatic dynamics that occurs on multiple coupled potential energy surfaces. Moreover, the propensity for NO(A2Σ+) electronic quenching depends heavily on the strength and nature of the intermolecular interactions between NO(A2Σ+) and the molecular partner. In this paper, we explore the electronic quenching mechanisms of three systems: NO(A2Σ+) + CH4, NO(A2Σ+) + CH3OH, and NO(A2Σ+) + CO2. Using EOM-EA-CCSD calculations, we rationalize the very low electronic quenching cross-section of NO(A2Σ+) + CH4 as well as the outcomes observed in previous NO + CH4 photodissociation studies. Our analysis of NO(A2Σ+) + CH3OH suggests that it will undergo facile electronic quenching mediated by reducing the intermolecular distance and significantly stretching the O-H bond of CH3OH. For NO(A2Σ+) + CO2, intermolecular attractions lead to a series of low-energy ON-OCO conformations in which the CO2 is significantly bent. For both the NO(A2Σ+) + CH3OH and NO(A2Σ+) + CO2 systems, we see evidence of the harpoon mechanism and low-energy conical intersections between NO(A2Σ+) + M and NO(X2Π) + M. Overall, this work provides the first detailed theoretical study on the NO(A2Σ+) + M potential energy surface of each of these systems and will inform future velocity map imaging experiments.
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Affiliation(s)
- Aerial
N. Bridgers
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United
States
| | - Justin A. Urquilla
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United
States
| | - Julia Im
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United
States
| | - Andrew S. Petit
- Department of Chemistry and Biochemistry, California State University—Fullerton, Fullerton, California 92834-6866, United
States
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4
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Luxford TM, Sharples TR, Fournier M, Soulié C, Paterson MJ, McKendrick KG, Costen ML. Differential Cross Sections for Pair-Correlated Rotational Energy Transfer in NO(A 2Σ +) + N 2, CO, and O 2: Signatures of Quenching Dynamics. J Phys Chem A 2023; 127:6251-6266. [PMID: 37481777 PMCID: PMC10405210 DOI: 10.1021/acs.jpca.3c03606] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 07/07/2023] [Indexed: 07/25/2023]
Abstract
A crossed molecular beam, velocity-map ion-imaging apparatus has been used to determine differential cross sections (DCSs), as a function of collider final internal energy, for rotationally inelastic scattering of NO(A2Σ+, v = 0, j = 0.5f1) with N2, CO, and O2, at average collision energies close to 800 cm-1. DCSs are strongly forward scattered for all three colliders for all observed NO(A) final rotational states, N'. For collisions with N2 and CO, the fraction of NO(A) that is scattered sideways and backward increases with increasing N', as does the internal rotational excitation of the colliders, with N2 having the highest internal excitation. In contrast, the DCSs for collisions with O2 are essentially only forward scattered, with little rotational excitation of the O2. The sideways and backward scattering expected from low-impact-parameter collisions, and the rotational excitation expected from the orientational dependence of published van der Waals potential energy surfaces (PESs), are absent in the observed NO(A) + O2 results. This is consistent with the removal of these short-range scattering trajectories via facile electronic quenching of NO(A) by O2, in agreement with the literature determination of the coupled NO-O2 PESs and the associated conical intersections. In contrast, collisions at high-impact parameter that predominately sample the attractive van der Waals minimum do not experience quenching and are inelastically forward scattered with low rotational excitation.
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Holmes-Ross HL, Gascooke JR, Lawrance WD. Correlated Product Distributions in the Photodissociation of à State NO–CH 4 and NO–N 2 van der Waals Complexes. J Phys Chem A 2022; 126:7981-7996. [DOI: 10.1021/acs.jpca.2c06312] [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)
- Heather L. Holmes-Ross
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia5001, Australia
| | - Jason R. Gascooke
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia5001, Australia
| | - Warren D. Lawrance
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, South Australia5001, Australia
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6
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Parsons BF, Rivera MR, Onder MK. NO (A) Rotational State Distributions from Photodissociation of the N 2-NO Complex. J Phys Chem A 2022; 126:5729-5737. [PMID: 35994689 DOI: 10.1021/acs.jpca.2c04265] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have recorded the resonance-enhanced multiphoton ionization spectrum for NO (A) products from photodissociation of the N2-NO complex. We made measurements at excitation energies ranging from 28 to 758 cm-1 above the threshold to produce NO (A) + N2 (X) products, and the resulting spectra reveal the NO (A) rotational states formed during dissociation, allowing us to determine the rotational state distribution. At the lowest available energies, 28 and 50 cm-1 above threshold, we observed contributions from NO (A) rotational states that exceed the available energy and must originate from excitation due to hotbands of the complex. At all higher energies, we did not observe any energetically disallowed NO (A) rotational states, and for all available energies above 259 cm-1 the observed rotational transitions do not extend to the maximum allowed by energy conservation. Furthermore, the observed distributions were typically biased toward low rotational states, in contrast with expectations from vibrational predissociation. From the rotational state distributions, we determined the average fraction of energy partitioned into NO (A) rotation, fNO rot, ave, to be 0.088 at the highest available energy, and this fraction increased as the available energy decreased. By combining the average NO (A) rotational energy along with the average center-of-mass translational energy from our previous work, we determined the average rotational energy for the undetected N2 (X) photoproduct. The results showed that the N2 fragment has a higher average rotational energy relative to the NO fragment. Finally, we found that the NO (A) rotational state distribution was colder than expected for a statistical dissociation.
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Affiliation(s)
- Bradley F Parsons
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Marcos R Rivera
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Michael K Onder
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
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Parsons BF, Draney AW, Warder HJ, Rivera MR, Onder MK. Anisotropy Measurements from the Near-Threshold Photodissociation of the N 2-NO Complex. J Phys Chem A 2022; 126:1386-1392. [PMID: 35179379 DOI: 10.1021/acs.jpca.1c10514] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have used velocity map ion imaging to measure the angular anisotropy of the NO (A) products from the photodissociation of the N2-NO complex. Our experiment ranged from 108 to 758 cm-1 above the threshold energy to form NO (A) + N2 (X) products, and these measurements reveal, for the first time, a strong angular anisotropy from photodissociation. At 108 cm-1 above the photodissociation threshold, we observed NO (A) photoproducts recoil preferentially perpendicular to the laser polarization axis with an average anisotropy parameter, β = -0.25; however, as the available energy was increased, the anisotropy increased, and at 758 cm-1 above the threshold energy, we found an average β = +0.28. The observed changes in the angular anisotropy of the NO (A) photoproduct are qualitatively similar to those observed for the photodissociation of the Ar-NO complex and likely result from changes in the region of the excited state potential energy surface accessed during the electronic excitation. At the lowest available energy, we also noted a large contribution from hotband excitation; however, this contribution decreased as the available energy increased. The outsized contribution at the lowest available energy may result from hotbands having better Franck-Condon overlap with the excited electronic state near threshold. Finally, we contrast the experimental center of mass translational energy distribution with a statistical energy distribution determined from phase space theory. The experimental and statistical distributions show pronounced disagreement, particularly at low kinetic energies, with the experimental one showing less dissociation resulting in high rotational levels of the fragments.
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Affiliation(s)
- Bradley F Parsons
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Adrian W Draney
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Hunter J Warder
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Marcos R Rivera
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
| | - Michael K Onder
- Department of Chemistry and Biochemistry, Creighton University, 2500 California Plaza, Omaha, Nebraska 68178, United States
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Guardado JL, Urquilla JA, Kidwell NM, Petit AS. Reactive quenching of NO (A 2Σ +) with H 2O leads to HONO: a theoretical analysis of the reactive and nonreactive electronic quenching mechanisms. Phys Chem Chem Phys 2022; 24:26717-26730. [DOI: 10.1039/d2cp04214b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this study, we develop a mechanistic understanding of the pathways for nonreactive and reactive electronic quenching of NO (A2Σ+) with H2O. In doing so, we identify a photochemical mechanism for HONO production in the upper atmosphere.
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Affiliation(s)
- José L. Guardado
- Department of Chemistry and Biochemistry, California State University – Fullerton, Fullerton, CA 92834-6866, USA
| | - Justin A. Urquilla
- Department of Chemistry and Biochemistry, California State University – Fullerton, Fullerton, CA 92834-6866, USA
| | - Nathanael M. Kidwell
- Department of Chemistry, The College of William and Mary, Williamsburg, VA 23187-8795, USA
| | - Andrew S. Petit
- Department of Chemistry and Biochemistry, California State University – Fullerton, Fullerton, CA 92834-6866, USA
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