1
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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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2
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Tang G, Besemer M, Onvlee J, Karman T, van der Avoird A, Groenenboom GC, van de Meerakker SYT. Correlated rotational excitations in NO–CO inelastic collisions. J Chem Phys 2022; 156:214304. [DOI: 10.1063/5.0092561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a joint experimental and theoretical study of rotationally inelastic collisions between NO ( X2Π1/2, ν = 0, j = 1/2, f) radicals and CO ( X1Σ+, ν = 0, j = 0) molecules at a collision energy of 220 cm−1. State-to-state scattering images for excitation of NO radicals into various final states were measured with high resolution by combining the Stark deceleration and velocity map imaging techniques. The high image resolution afforded the observation of correlated rotational excitations of NO–CO pairs, which revealed a number of striking scattering phenomena. The so-called “parity-pair” transitions in NO are found to have similar differential cross sections, independent of the concurrent excitation of CO, extending this well-known effect for collisions between NO and rare gas atoms into the realm of bimolecular collisions. Forward scattering is found for collisions that induce a large amount of rotational energy transfer (in either NO, CO, or both), which require low impact parameters to induce sufficient energy transfer. This observation is interpreted in terms of the recently discovered hard collision glory scattering mechanism, which predicts the forward bending of initially backward receding trajectories if the energy uptake in the collision is substantial in relation to the collision energy. The experimental results are in good agreement with the predictions from coupled-channels quantum scattering calculations based on an ab initio NO–CO potential energy surface.
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Affiliation(s)
- Guoqiang Tang
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Matthieu Besemer
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Jolijn Onvlee
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Tijs Karman
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Ad van der Avoird
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Gerrit C. Groenenboom
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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3
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Heid CG, Bentham IP, Gheorghe R, Jambrina PG, Aoiz FJ, Brouard M. Inelastic collision dynamics of oriented NO molecules with Kr atoms. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1946607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Cornelia G. Heid
- Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Imogen P. Bentham
- Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Razvan Gheorghe
- Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Pablo G. Jambrina
- Departamento de Química Física, Universidad de Salamanca, Salamanca, Spain
| | - F. Javier Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, Madrid, Spain
| | - Mark Brouard
- Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, Oxford, UK
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4
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Heid CG, Bentham IP, Walpole V, Jambrina PG, Aoiz FJ, Brouard M. Controlling the Spin-Orbit Branching Fraction in Molecular Collisions. J Phys Chem Lett 2021; 12:310-316. [PMID: 33351625 DOI: 10.1021/acs.jpclett.0c02941] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The collision geometry, that is, the relative orientation of reactants before interaction, can have a large effect on how a collision or reaction proceeds. Certain geometries may prevent access to a given product channel, while others might enhance it. In this Letter, we demonstrate how the initial orientation of NO molecules relative to approaching Ar atoms determines the branching between the spin-orbit changing and the spin-orbit conserving rotational product channels. We use a recently developed quantum treatment to calculate differential and integral branching fractions, at any arbitrary orientation, from theoretical and experimental data points. Our results show that a substantial degree of control over the final spin-orbit state of the scattering products can be achieved by tuning the initial collision geometry.
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Affiliation(s)
- Cornelia G Heid
- Department of Chemistry, University of Oxford, The Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Imogen P Bentham
- Department of Chemistry, University of Oxford, The Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Victoria Walpole
- Department of Chemistry, University of Oxford, The Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Pablo G Jambrina
- Departamento de Química Física, Universidad de Salamanca, 37008 Salamanca, Spain
| | - F Javier Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - Mark Brouard
- Department of Chemistry, University of Oxford, The Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, United Kingdom
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5
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Heid CG, Bentham IP, Walpole V, Gheorghe R, Jambrina PG, Aoiz FJ, Brouard M. Probing the location of the unpaired electron in spin-orbit changing collisions of NO with Ar. Phys Chem Chem Phys 2020; 22:22289-22301. [PMID: 33005915 DOI: 10.1039/d0cp04228e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Understanding the molecular forces that drive a reaction or scattering process lies at the heart of molecular dynamics. Here, we present a combined experimental and theoretical study of the spin-orbit changing scattering dynamics of oriented NO molecules with Ar atoms. Using our crossed molecular beam apparatus, we have recorded velocity-map ion images and extracted differential and integral cross sections of the scattering process in the side-on geometry. We observe an overall preference for collisions close to the N atom in the spin-orbit changing manifold, which is a direct consequence of the location of the unpaired electron on the potential energy surface. In addition, a prominent forward scattered feature is observed for intermediate, even rotational transitions when the atom approaches the molecule from the O-end. The appearance of this peak originates from an attractive well on the A' potential energy surface, which efficiently directs high impact parameter trajectories towards the region of high unpaired electron density near the N-end of the molecule. The ability to orient molecules prior to collision, both experimentally and theoretically, allows us to sample different regions of the potential energy surface(s) and unveil the associated collision pathways.
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Affiliation(s)
- Cornelia G Heid
- Department of Chemistry, University of Oxford, The Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, UK.
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6
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Tang G, Besemer M, de Jongh T, Shuai Q, van der Avoird A, Groenenboom GC, van de Meerakker SYT. Correlations in rotational energy transfer for NO-D 2 inelastic collisions. J Chem Phys 2020; 153:064301. [PMID: 35287454 DOI: 10.1063/5.0019472] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a combined experimental and theoretical study of state-to-state inelastic collisions between NO (X 2Π1/2, j = 1/2, f) radicals and D2 (j = 0, 1, 2, 3) molecules at collision energies of 100 cm-1 and 750 cm-1. Using the combination of Stark deceleration and velocity map imaging, we fully resolve pair-correlated excitations in the scattered molecules. Both spin-orbit conserving and spin-orbit changing transitions in the NO radical are measured, while the coincident rotational excitation (j = 0 → j = 2) and rotational de-excitation (j = 2 → j = 0 and j = 3 → j = 1) in D2 are observed. De-excitation of D2 shows a strong dependence on the spin-orbit excitation of NO. We observe translation-to-rotation energy transfer as well as direct rotation-to-rotation energy transfer at the lowest collision energy probed. The experimental results are in good agreement with cross sections obtained from quantum coupled-channels calculations based on recent NO-D2 potential energy surfaces. The observed trends in the correlated scattering cross sections are understood in terms of the NO-D2 quadrupole-quadrupole interaction.
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Affiliation(s)
- Guoqiang Tang
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Matthieu Besemer
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Tim de Jongh
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Quan Shuai
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Ad van der Avoird
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Gerrit C Groenenboom
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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7
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Affiliation(s)
- Sean D. S. Gordon
- Institute for Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Present address: EPFL Innovation Park, Building C, 1015 Lausanne, Switzerland
| | - Andreas Osterwalder
- Institute for Chemical Sciences and Engineering (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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8
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Walpole V, Heid CG, Jambrina PG, Aoiz FJ, Brouard M. Steric Effects in the Inelastic Scattering of NO(X) + Ar: Side-on Orientation. J Phys Chem A 2019; 123:8787-8806. [PMID: 31513425 DOI: 10.1021/acs.jpca.9b07264] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rotationally inelastic collisions of NO(X) with Ar, in which the NO bond-axis is oriented side-on (i.e., perpendicular) to the incoming collision partner, are investigated experimentally and theoretically. The NO(X) molecules are selected in the |j = 0.5, Ω = 0.5, ε = -1, f⟩ state prior to bond-axis orientation in a static electric field. The scattered NO products are then state selectively detected using velocity-map ion imaging. The experimental bond-axis orientation resolved differential cross sections and integral steric asymmetries are compared with quantum mechanical calculations, and are shown to be in good agreement. The strength of the orientation field is shown to affect the structure observed in the differential cross sections, and to some extent also the steric preference, depending on the ratio of the initial e and f Λ-doublets in the superposition determined by the orientation field. Classical and quantum calculations are compared and used to rationalize the structures observed in the differential cross sections. It is found that these structures are due to quantum mechanical interference effects, which differ for the two possible orientations of the NO molecule due to the anisotropy of the potential energy surface probed in the side-on orientation. Side-on collisions are shown to maximize and afford a high degree of control over the scattering intensity at small scattering angles (θ < 90°), while end-on collisions are predicted to dominate in the backward scattered region (θ > 90°).
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Affiliation(s)
- Victoria Walpole
- The Department of Chemistry , University of Oxford, Chemistry Research Laboratory , 12 Mansfield Road , Oxford OX1 3TA , U.K
| | - Cornelia G Heid
- The Department of Chemistry , University of Oxford, Chemistry Research Laboratory , 12 Mansfield Road , Oxford OX1 3TA , U.K
| | - Pablo G Jambrina
- Departamento de Química Física , Universidad de Salamanca , 37008 , Salamanca , Spain
| | - F Javier Aoiz
- Departamento de Química Física, Facultad de Química , Universidad Complutense , 28040 Madrid , Spain
| | - Mark Brouard
- The Department of Chemistry , University of Oxford, Chemistry Research Laboratory , 12 Mansfield Road , Oxford OX1 3TA , U.K
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9
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Brouard M, Gordon SDS, Nichols B, Walpole V, Aoiz FJ, Stolte S. Differential steric effects in the inelastic scattering of NO(X) + Ar: spin-orbit changing transitions. Phys Chem Chem Phys 2019; 21:14173-14185. [PMID: 30444242 DOI: 10.1039/c8cp06225k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Spin-orbit changing transitions for bond-axis oriented collisions of NO(X) with Ar have been investigated with full quantum state selection via a crossed molecular beam experiment at collision energies of 532 cm-1 and 651 cm-1. NO(X) molecules were selected in their ground rotational state (Ω = 0.5, j = 0.5, f) before being adiabatically oriented using a static electric field, such that either the N- or O-end of the molecule was directed towards the incoming Ar atom. After collision, NO(X, Ω' = 1.5, j', e) molecules were probed quantum state specifically using velocity-map ion imaging, coupled with resonantly enhanced multi-photon ionization. Differences were observed between the experimental ion images and differential cross sections for collisions occurring at the two ends of the molecule, with results that could largely be accounted for by quantum mechanical scattering calculations. The bond-axis oriented data for the spin-orbit changing collisions are compared with similar results obtained previously for spin-orbit conserving transitions, and for field free scattering of NO(X) with Ar.
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Affiliation(s)
- M Brouard
- The Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford OX1 3TA, UK.
| | - S D S Gordon
- The Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford OX1 3TA, UK.
| | - B Nichols
- The Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford OX1 3TA, UK.
| | - V Walpole
- The Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd, Oxford OX1 3TA, UK.
| | - F J Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain.
| | - S Stolte
- The Jilin Institute of Atomic and Molecular Physics, Qianjin Avenue, Changchung, 130012, China. and Department of Physics and Astronomy, LaserLaB, Vrije Universiteit, Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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10
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Gao Z, Loreau J, van der Avoird A, van de Meerakker SYT. Direct observation of product-pair correlations in rotationally inelastic collisions of ND 3 with D 2. Phys Chem Chem Phys 2019; 21:14033-14041. [PMID: 30649107 DOI: 10.1039/c8cp07109h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a combined experimental and theoretical study of state-to-state inelastic scattering of ND3(j = 11-) with D2 (j = 0, 1, 2, 3) molecules at collision energies around 800 cm-1. Using a crossed molecular beam apparatus which employs the combination of Stark deceleration and velocity map imaging, we observe the correlated rotational excitations of both collision partners. For D2, both elastic (ΔjD2 = 0), inelastic excitation (j = 0 →j = 2) and inelastic de-excitation (j = 2 →j = 0) processes are observed. For a number of final ND3 states, inelastic channels in which D2 is rotationally excited or de-excited appear surprisingly strong. The experimental results are in excellent agreement with the predictions from quantum scattering calculations which are based on an ab initio ND3-D2 potential energy surface.
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Affiliation(s)
- Zhi Gao
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
| | - Jérôme Loreau
- Service de Chimie Quantique et Photophysique, Université libre de Bruxelles, CP 160/09, 1050 Brussels, Belgium.
| | - Ad van der Avoird
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
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11
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12
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Sharples TR, Leng JG, Luxford TFM, McKendrick KG, Jambrina PG, Aoiz FJ, Chandler DW, Costen ML. Non-intuitive rotational reorientation in collisions of NO(A 2Σ+) with Ne from direct measurement of a four-vector correlation. Nat Chem 2018; 10:1148-1153. [DOI: 10.1038/s41557-018-0121-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 07/12/2018] [Indexed: 11/09/2022]
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13
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Gao Z, Karman T, Tang G, van der Avoird A, Groenenboom GC, van de Meerakker SYT. Correlated energy transfer in rotationally and spin-orbit inelastic collisions of NO(X 2Π 1/2, j = 1/2f) with O 2(X 3Σ g-). Phys Chem Chem Phys 2018; 20:12444-12453. [PMID: 29697730 DOI: 10.1039/c8cp01784k] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a combined experimental and theoretical study of state-to-state inelastic scattering of NO(X2Π1/2, j = 1/2f) with O2(X3Σg-) molecules at a collision energy of 480 cm-1, focusing in particular on the observation and interpretation of correlated excitations in both NO and O2. Various final states of the NO radical, in both spin-orbit manifolds, were measured with high resolution using a crossed molecular beam apparatus which employs a combination of Stark deceleration and velocity map imaging. Velocity map imaging directly measures both the angular distribution and the radial velocity distribution of the scattered NO molecules, which probes the kinetic energy uptake or release and hence correlated excitations of NO-O2 pairs. Simultaneous excitations of NO and O2 were resolved for all studied final states of NO. In all cases, the experimental results excellently agree with the results of simulations based on quantum scattering calculations. Trends are discussed by analyzing the scattering wave functions from the calculations.
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Affiliation(s)
- Zhi Gao
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
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14
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Reid KL. Accessing the molecular frame through strong-field alignment of distributions of gas phase molecules. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2018; 376:rsta.2017.0158. [PMID: 29431684 PMCID: PMC5805919 DOI: 10.1098/rsta.2017.0158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/25/2017] [Indexed: 06/08/2023]
Abstract
A rationale for creating highly aligned distributions of molecules is that it enables vector properties referenced to molecule-fixed axes (the molecular frame) to be determined. In the present work, the degree of alignment that is necessary for this to be achieved in practice is explored. Alignment is commonly parametrized in experiments by a single parameter, [Formula: see text], which is insufficient to enable predictive calculations to be performed. Here, it is shown that, if the full distribution of molecular axes takes a Gaussian form, this single parameter can be used to determine the complete set of alignment moments needed to characterize the distribution. In order to demonstrate the degree of alignment that is required to approach the molecular frame, the alignment moments corresponding to a few chosen values of [Formula: see text] are used to project a model molecular frame photoelectron angular distribution into the laboratory frame. These calculations show that [Formula: see text] needs to approach 0.9 in order to avoid significant blurring to be caused by averaging.This article is part of the theme issue 'Modern theoretical chemistry'.
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Affiliation(s)
- Katharine L Reid
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK
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15
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Gao Z, Vogels SN, Besemer M, Karman T, Groenenboom GC, van der Avoird A, van de Meerakker SYT. State-to-State Differential Cross Sections for Inelastic Collisions of NO Radicals with para-H 2 and ortho-D 2. J Phys Chem A 2017; 121:7446-7454. [PMID: 28910536 PMCID: PMC5677768 DOI: 10.1021/acs.jpca.7b06808] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
![]()
We
present state-to-state differential cross sections for collisions
of NO molecules (X2Π1/2, j = 1/2f) with para-H2 and ortho-D2 molecules, at a collision
energy of 510 and 450 cm–1, respectively. The angular
scattering distributions for various final states of the NO radical
are measured with high resolution using a crossed molecular beam apparatus
that employs the combination of Stark deceleration and velocity map
imaging. Rotational rainbows as well as diffraction oscillations are
fully resolved in the scattering images. The observed angular scattering
distributions are in excellent agreement with the cross sections obtained
from quantum close-coupling scattering calculations based on recently
computed NO–H2 potential energy surfaces, except
for excitation of NO into the j = 7/2f channel. For
this particular inelastic channel, a significant discrepancy with
theory is observed, despite various additional measurements and calculations,
at present, not understood.
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Affiliation(s)
- Zhi Gao
- Radboud University , Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Sjoerd N Vogels
- Radboud University , Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Matthieu Besemer
- Radboud University , Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Tijs Karman
- Radboud University , Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Gerrit C Groenenboom
- Radboud University , Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Ad van der Avoird
- Radboud University , Institute for Molecules and Materials, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
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16
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Chandler DW, Houston PL, Parker DH. Perspective: Advanced particle imaging. J Chem Phys 2017; 147:013601. [PMID: 28688442 PMCID: PMC5648558 DOI: 10.1063/1.4983623] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/18/2017] [Indexed: 11/14/2022] Open
Abstract
Since the first ion imaging experiment [D. W. Chandler and P. L. Houston, J. Chem. Phys. 87, 1445-1447 (1987)], demonstrating the capability of collecting an image of the photofragments from a unimolecular dissociation event and analyzing that image to obtain the three-dimensional velocity distribution of the fragments, the efficacy and breadth of application of the ion imaging technique have continued to improve and grow. With the addition of velocity mapping, ion/electron centroiding, and slice imaging techniques, the versatility and velocity resolution have been unmatched. Recent improvements in molecular beam, laser, sensor, and computer technology are allowing even more advanced particle imaging experiments, and eventually we can expect multi-mass imaging with co-variance and full coincidence capability on a single shot basis with repetition rates in the kilohertz range. This progress should further enable "complete" experiments-the holy grail of molecular dynamics-where all quantum numbers of reactants and products of a bimolecular scattering event are fully determined and even under our control.
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Affiliation(s)
- David W Chandler
- Sandia National Laboratories, Combustion Research Facility, Livermore, California 94550, USA
| | - Paul L Houston
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - David H Parker
- Department of Laser and Molecular Physics, Radboud University of Nijmegen, Nijmegen, Netherlands
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17
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Luxford TFM, Sharples TR, McKendrick KG, Costen ML. Pair-correlated stereodynamics for diatom-diatom rotational energy transfer: NO(A2Σ+) + N2. J Chem Phys 2017; 147:013912. [DOI: 10.1063/1.4979487] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Thomas F. M. Luxford
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Thomas R. Sharples
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Kenneth G. McKendrick
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Matthew. L. Costen
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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18
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Brouard M, Gordon SDS, Hackett Boyle A, Heid CG, Nichols B, Walpole V, Aoiz FJ, Stolte S. Integral steric asymmetry in the inelastic scattering of NO(X 2Π). J Chem Phys 2017; 146:014302. [PMID: 28063434 DOI: 10.1063/1.4972565] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The integral steric asymmetry for the inelastic scattering of NO(X) by a variety of collision partners was recorded using a crossed molecular beam apparatus. The initial state of the NO(X, v = 0, j = 1/2, Ω=1/2, ϵ=-1,f) molecule was selected using a hexapole electric field, before the NO bond axis was oriented in a static electric field, allowing probing of the scattering of the collision partner at either the N- or O-end of the molecule. Scattered NO molecules were state selectively probed using (1 + 1') resonantly enhanced multiphoton ionisation, coupled with velocity-map ion imaging. Experimental integral steric asymmetries are presented for NO(X) + Ar, for both spin-orbit manifolds, and Kr, for the spin-orbit conserving manifold. The integral steric asymmetry for spin-orbit conserving and changing transitions of the NO(X) + O2 system is also presented. Close-coupled quantum mechanical scattering calculations employing well-tested ab initio potential energy surfaces were able to reproduce the steric asymmetry observed for the NO-rare gas systems. Quantum mechanical scattering and quasi-classical trajectory calculations were further used to help interpret the integral steric asymmetry for NO + O2. Whilst the main features of the integral steric asymmetry of NO with the rare gases are also observed for the O2 collision partner, some subtle differences provide insight into the form of the underlying potentials for the more complex system.
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Affiliation(s)
- M Brouard
- The Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - S D S Gordon
- The Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - A Hackett Boyle
- The Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - C G Heid
- The Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - B Nichols
- The Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - V Walpole
- The Department of Chemistry, The Chemistry Research Laboratory, University of Oxford, 12 Mansfield Road, OX1 3TA Oxford, United Kingdom
| | - F J Aoiz
- Departamento de Química Física, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - S Stolte
- The Jilin Institute of Atomic and Molecular Physics, Qianjin Avenue, Changchung 130012, China
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Luxford TFM, Sharples TR, McKendrick KG, Costen ML. Experimental testing of ab initio potential energy surfaces: Stereodynamics of NO(A 2Σ +) + Ne inelastic scattering at multiple collision energies. J Chem Phys 2016; 145:174304. [PMID: 27825214 DOI: 10.1063/1.4966688] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a crossed molecular beam velocity-map ion imaging study of state-to-state rotational energy transfer of NO(A2Σ+, v = 0, N = 0, j = 0.5) in collisions with Ne atoms. From these measurements, we report differential cross sections and angle-resolved rotational angular momentum alignment moments for product states N' = 3 and 5-10 for collisions at an average energy of 523 cm-1, and N' = 3 and 5-14 for collisions at an average energy of 1309 cm-1, respectively. The experimental results are compared to the results of close-coupled quantum scattering calculations on two literature ab initio potential energy surfaces (PESs) [Pajón-Suárez et al., Chem. Phys. Lett. 429, 389 (2006) and Cybulski and Fernández, J. Phys. Chem. A 116, 7319 (2012)]. The differential cross sections from both experiment and theory show clear rotational rainbow structures at both collision energies, and comparison of the angles observed for the rainbow peaks leads to the conclusion that Cybulski and Fernández PES better represents the NO(A2Σ+)-Ne interaction at the collision energies used here. Sharp, forward scattered (<10°), peaks are observed in the experimental differential cross sections for a wide range of N' at both collision energies, which are not reproduced by theory on either PES. We identify these as L-type rainbows, characteristic of attractive interactions, and consistent with a shallow well in the collinear Ne-N-O geometry, similar to that calculated for the NO(A2Σ+)-Ar surface [Kłos et al., J. Chem. Phys. 129, 244303 (2008)], but absent from both of the NO(A2Σ+)-Ne surfaces tested here. The angle-resolved alignment moments calculated by quantum scattering theory are generally in good agreement with the experimental results, but both experiment and quantum scattering theories are dramatically different to the predictions of a classical rigid-shell, kinematic-apse conservation model. Strong oscillations are resolved in the experimental alignment moments as a function of scattering angle, confirming and extending the preliminary report of this behavior [Steill et al., J. Phys. Chem. A 117, 8163 (2013)]. These oscillations are correlated with structure in the differential cross section, suggesting an interference effect is responsible for their appearance.
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Affiliation(s)
- Thomas F M Luxford
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Thomas R Sharples
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Kenneth G McKendrick
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
| | - Matthew L Costen
- Institute of Chemical Sciences, Heriot-Watt University, Edinburgh EH14 4AS, United Kingdom
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