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Plamper D, Fujioka K, Schmidt S, Sun R, Weitzel KM. Ion-molecule reactions in the HBr + + HCl (DCl) system: a combined experimental and theoretical study. Phys Chem Chem Phys 2023; 25:2629-2640. [PMID: 36602406 DOI: 10.1039/d2cp03654a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Reactions in the system HBr+ + HCl (DCl) were investigated inside a guided ion-beam apparatus under single-collision conditions. In the HBr+ + HCl system, the proton transfer (PTHCl) and charge transfer (CT) are observable. In the HBr+ + DCl system, proton transfer (PTDCl) and deuterium abstraction (DA) are accessible. The cross sections for all reaction channels were measured as a function of the collision energy Ecm and of the rotational energy Erot of the ion. The rotationally state-selective formation of the ionic species was realized by resonance-enhanced multiphoton ionization (REMPI). As expected, the PT-channels are exothermic, and the cross section decreases with increasing collision energy for both PTHCl and PTDCl. The cross section for DA also decreases with an increasing Ec.m.. In the case of a considerably endothermic CT-channel, the reaction efficiency increases with increasing collision energy but has an overall much smaller cross sections compared to PT and DA reactions. Both PT-reactions are hindered by ion rotation, whereas DA is independent of Erot. The CT-channel shows a rotational enhancement near the thermochemical threshold. The experiment is complemented by theory, using ab initio molecular dynamics (AIMD, also known as direct dynamics) simulations and taking the rotational enhancement of HBr+ into account. The simulations show good agreement with the experimental results. The cross section of PTHCl decreases with an increase of the rotational energy. Furthermore, the absolute cross sections are in the same order of magnitude. The CT channel shows no reactions in the simulation.
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Affiliation(s)
- Dominik Plamper
- Philipps-Universität Marburg, Fachbereich Chemie, 35032 Marburg, Germany.
| | - Kazuumi Fujioka
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
| | - Sebastian Schmidt
- Philipps-Universität Marburg, Fachbereich Chemie, 35032 Marburg, Germany.
| | - Rui Sun
- Department of Chemistry, University of Hawai'i at Manoa, Honolulu, Hawaii 96822, USA.
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Hillenbrand PM, Bowen KP, Dayou F, Miller KA, de Ruette N, Urbain X, Savin DW. Experimental study of the proton-transfer reaction C + H 2+ → CH + + H and its isotopic variant (D 2+). Phys Chem Chem Phys 2020; 22:27364-27384. [PMID: 33231243 DOI: 10.1039/d0cp04810k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report absolute integral cross section (ICS) measurements using a dual-source merged-fast-beams apparatus to study the titular reactions over the relative translational energy range of Er ∼ 0.01-10 eV. We used photodetachment of C- to produce a pure beam of atomic C in the ground electronic 3P term, with statistically populated fine-structure levels. The H2+ and D2+ were formed in an electron impact ionization source, with well known vibrational and rotational distributions. The experimental work is complemented by a theoretical study of the CH2+ electronic system in the reactant and product channels, which helps to clarify the possible reaction mechanisms underlying the ICS measurements. Our measurements provide evidence that the reactions are barrierless and exoergic. They also indicate the apparent absence of an intermolecular isotope effect, to within the total experimental uncertainties. Capture models, taking into account either the charge-induced dipole interaction potential or the combined charge-quadrupole and charge-induced dipole interaction potentials, produce reaction cross sections that lie a factor of ∼4 above the experimental results. Based on our theoretical study, we hypothesize that the reaction is most likely to proceed adiabatically through the 14A' and 14A'' states of CH2+via the reaction C(3P) + H2+(2Σ+g) → CH+(3Π) + H(2S). We also hypothesize that at low collision energies only H2+(v ≤ 2) and D2+(v ≤ 3) contribute to the titular reactions, due to the onset of dissociative charge transfer for higher vibrational v levels. Incorporating these assumptions into the capture models brings them into better agreement with the experimental results. Still, for energies ⪅0.1 eV where capture models are most relevant, the modified charge-induced dipole model yields reaction cross sections with an incorrect energy dependence and lying ∼10% below the experimental results. The capture cross section obtained from the combined charge-quadrupole and charge-induced dipole model better matches the measured energy dependence but lies ∼30-50% above the experimental results. These findings provide important guidance for future quasiclassical trajectory and quantum mechanical treatments of this reaction.
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Xu Y, Chang YC, Parziale M, Wannenmacher A, Ng CY. Chemical Activation of Water Molecule by Collision with Spin-Orbit-State-Selected Vanadium Cation: Quantum-Electronic-State Control of Chemical Reactivity. J Phys Chem A 2020; 124:8884-8896. [PMID: 33078936 DOI: 10.1021/acs.jpca.0c07884] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have obtained absolute integral cross sections (σ's) for the reactions of spin-orbit-state-selected vanadium cations, V+[a5DJ(J = 0, 2), a5FJ(J = 1, 2), and a3FJ(J = 2, 3)], with a water molecule (H2O) in the center-of-mass collision energy range Ecm = 0.1-10.0 eV. On the basis of these state-selected σ curves (σ versus Ecm plots) observed, three reaction product channels, VO+ + H2, VH+ + OH, and VOH+ + H, from the V+ + H2O reaction are unambiguously identified. Contrary to the previous guided ion beam study of the V+(a5DJ) + D2O reaction, we have observed the formation of the VO+ + H2 channel from the V+(a5DJ) + H2O ground reactant state at low Ecm's (<3.0 eV). No spin-orbit J-state dependences for the σ curves of individual electronic states are discernible, indicating that spin-orbit interactions are weak with little effect on chemical reactivity of the titled reaction. For the three product channels identified, the triplet σ(a3FJ) values are overwhelmingly higher than the quintet σ(a5DJ) and σ(a5FJ) values, showing that the reaction is governed by a "weak quintet-triplet spin crossing" mechanism, favoring the conservation of total electron spins. The σ curves for exothermic product channels are found to exhibit a rapid decreasing profile as Ecm is increased, an observation consistent with the prediction of the charge-dipole and induced-dipole orbiting model. This experiment shows that the V+ + H2O reaction can be controlled effectively to produce predominantly the VO+ + H2 channel via the V+(a3FJ) + H2O reaction at low Ecm's (≤0.1 eV) and that the ion-molecule reaction dynamics can be altered readily by selecting the electronic state of V+ cation. On the basis of the measured Ecm thresholds for the σ(a5DJ, a5FJ, and a3FJ: VH+) and σ(a5DJ, a5FJ, and a3FJ: VOH+) curves, we have deduced upper bound values of 2.6 ± 0.2 and 4.3 ± 0.3 eV for the 0 K bond dissociation energies, D0(V+-H) and D0(V+-OH), respectively. After correcting for the kinetic energy distribution resulting from the Doppler broadening effect of the H2O molecule, we obtain D0(V+-H) = 2.2 ± 0.2 eV and D0(V+-OH) = 4.0 ± 0.3 eV, which are in agreement with D0 determinations obtained by σ curve simulations.
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Affiliation(s)
- Yuntao Xu
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Yih-Chung Chang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Matthew Parziale
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Anna Wannenmacher
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Cheuk-Yiu Ng
- Department of Chemistry, University of California, Davis, California 95616, United States
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Ryazantsev SV, Zasimov PV, Feldman VI. Radiation-induced synthesis of formic acid in the H2O–CO system: A matrix isolation study. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137540] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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5
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Xu Y, Chang YC, Ng CY. Chemical Activation of a Deuterium Molecule by Collision with a Quantum Electronic State-Selected Vanadium Cation. J Phys Chem A 2019; 123:5937-5944. [DOI: 10.1021/acs.jpca.9b04644] [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)
- Yuntao Xu
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Yih-Chung Chang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Cheuk-Yiu Ng
- Department of Chemistry, University of California, Davis, California 95616, United States
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6
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Chang YC, Xu Y, Ng CY. Quantum state control on the chemical reactivity of a transition metal vanadium cation in carbon dioxide activation. Phys Chem Chem Phys 2019; 21:6868-6877. [PMID: 30887995 DOI: 10.1039/c9cp00575g] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
By combining a newly developed two-color laser pulsed field ionization-photoion (PFI-PI) source and a double-quadrupole-double-octopole (DQDO) mass spectrometer, we investigated the integral cross sections (σs) of the vanadium cation (V+) toward the activation of CO2 in the center-of-mass kinetic energy (Ecm) range from 0.1 to 10.0 eV. Here, V+ was prepared in single spin-orbit levels of its lowest electronic states, a5DJ (J = 0-4), a5FJ (J = 1-5), and a3FJ (J = 2-4), with well-defined kinetic energies. For both product channels VO+ + CO and VCO+ + O identified, V+(a3F2,3) is found to be greatly more reactive than V+(a5D0,2) and V+(a5F1,2), suggesting that the V+ + CO2 reaction system mainly proceeds via a "weak quintet-to-triplet spin-crossing" mechanism favoring the conservation of total electron spins. In addition, no J-state dependence was observed. The distinctive structures of the quantum electronic state selected integral cross sections observed as a function of Ecm and the electronic state of the V+ ion indicate that the difference in the chemical reactivity of the title reaction originated from the quantum-state instead of energy effects. Furthermore, this work suggests that the selection of the quantum electronic states a3FJ (J = 2-4) of the transition metal V+ ion can greatly enhance the efficiency of CO2 activation.
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Affiliation(s)
- Yih Chung Chang
- Department of Chemistry, University of California, Davis, Davis, CA 95616, USA.
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Chang YC, Xiong B, Xu Y, Ng CY. Quantum Spin–Orbit Electronic State Selection of Atomic Transition Metal Vanadium Cation for Chemical Reactivity Studies. J Phys Chem A 2019; 123:2310-2319. [DOI: 10.1021/acs.jpca.9b00511] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yih Chung Chang
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Bo Xiong
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Yuntao Xu
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Cheuk-Yiu Ng
- Department of Chemistry, University of California, Davis, California 95616, United States
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8
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Xu Y, Xiong B, Chang YC, Ng CY. Quantum-State-Selected Integral Cross Sections and Branching Ratios for the Ion–Molecule Reaction of N2+(X2Σg+: ν+ = 0–2) + C2H4 in the Collision Energy Range of 0.05–10.00 eV. J Phys Chem A 2018; 122:6491-6499. [DOI: 10.1021/acs.jpca.8b04587] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuntao Xu
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Bo Xiong
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Yih Chung Chang
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
| | - Cheuk-Yiu Ng
- Department of Chemistry, University of California, Davis, Davis, California 95616, United States
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9
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Cernuto A, Pirani F, Martini LM, Tosi P, Ascenzi D. The Selective Role of Long-Range Forces in the Stereodynamics of Ion-Molecule Reactions: The He + +Methyl Formate Case From Guided-Ion-Beam Experiments. Chemphyschem 2018; 19:51-59. [PMID: 29045020 DOI: 10.1002/cphc.201701096] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Indexed: 12/20/2022]
Abstract
Long-range intermolecular forces play a crucial role in controlling the outcome of ion-molecule chemical reactions, such as those determining the disappearance of organic or inorganic "complex" molecules recently detected in various regions of the interstellar medium due to collisions with abundant interstellar atomic ions (e.g. H+ and He+ ). Theoretical treatments, for example, based on simple capture models, are nowadays often adopted to evaluate the collision-energy dependence of reactive cross sections and the temperature dependent rate coefficients of many ion-molecule reactions. The obtained results are widely used for the modelling of phenomena occurring in different natural environments or technological applications such as astrophysical and laboratory plasmas. Herein it is demonstrated, through a combined experimental and theoretical investigation on a prototype ion-molecule reaction (He+ +methyl formate), that the dynamics, investigated in detail, shows some intriguing features that can lead to rate coefficients at odds with the expectations (e.g. Arrhenius versus anti-Arrhenius behaviour). Therefore, this study casts light on some new and general guidelines to be properly taken into account for a suitable evaluation of rate coefficients of ion-molecule reactions.
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Affiliation(s)
- Andrea Cernuto
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
| | - Fernando Pirani
- Dipartimento di Chimica, Biologia e Biotecnologie, Universitá di Perugia, Via Elce di Sotto 8, Perugia, Italy.,Istituto di Nanotecnologia (CNR NANOTEC), 70126, Bari, Italy
| | - Luca Matteo Martini
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
| | - Paolo Tosi
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
| | - Daniela Ascenzi
- Dipartimento di Fisica, Universitá di Trento, Via Sommarive 14, 38123, Trento, Italy
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Xiong B, Chang YC, Ng CY. A quantum-rovibrational-state-selected study of the proton-transfer reaction H 2+(X 2Σ: v + = 1-3; N + = 0-3) + Ne → NeH + + H using the pulsed field ionization-photoion method: observation of the rotational effect near the reaction threshold. Phys Chem Chem Phys 2017; 19:18619-18627. [PMID: 28692096 DOI: 10.1039/c7cp03963h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Using the sequential electric field pulsing scheme for vacuum ultraviolet (VUV) laser pulsed field ionization-photoion (PFI-PI) detection, we have successfully prepared H2+(X2Σ: v+ = 1-3; N+ = 0-5) ions in the form of an ion beam in single quantum-rovibrational-states with high purity, high intensity, and narrow laboratory kinetic energy spread (ΔElab ≈ 0.05 eV). This VUV-PFI-PI ion source, when coupled with the double-quadrupole double-octupole ion-molecule reaction apparatus, has made possible a systematic examination of the vibrational- as well as rotational-state effects on the proton transfer reaction of H2+(X2Σ: v+; N+) + Ne. Here, we present the integral cross sections [σ(v+; N+)'s] for the H2+(v+ = 1-3; N+ = 0-3) + Ne → NeH+ + H reaction observed in the center-of-mass kinetic energy (Ecm) range of 0.05-2.00 eV. The σ(v+ = 1, N+ = 1) exhibits a distinct Ecm onset, which is found to agree with the endothermicity of 0.27 eV for the proton transfer process after taking into account of experimental uncertainties. Strong v+-vibrational enhancements are observed for σ(v+ = 1-3, N+) in the Ecm range of 0.05-2.00 eV. While rotational excitations appear to have little effect on σ(v+ = 3, N+), a careful search leads to the observation of moderate N+-rotational enhancements at v+ = 2: σ(v+ = 2; N+ = 0) < σ(v+ = 2; N+ = 1) < σ(v+ = 2; N+ = 2) < σ(v+ = 2; N+ = 3), where the formation of NeH+ is near thermal-neutral. The σ(v+ = 1-3, N+ = 0-3) values obtained here are compared with previous experimental results and the most recent state-of-the-art quantum dynamics predictions. We hope that these new experimental results would further motivate more rigorous theoretical calculations on the dynamics of this prototypical ion-molecule reaction.
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Affiliation(s)
- Bo Xiong
- Department of Chemistry, University of California, Davis, CA 95616, USA.
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11
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Xiong B, Chang YC, Ng CY. Quantum-state-selected integral cross sections for the charge transfer collision of O2+(a4Πu5/2,3/2,1/2,−1/2: v+= 1–2; J+) [O2+(X2Πg3/2,1/2: v+= 22–23; J+)] + Ar at center-of-mass collision energies of 0.05–10.00 eV. Phys Chem Chem Phys 2017; 19:29057-29067. [DOI: 10.1039/c7cp04886f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Study of spin–orbit and rovibronically selected ion-molecule reactions between O2+(a4Πu,ν+= 1–2; X2Πg,ν+= 22–23) and Ar.
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Affiliation(s)
- Bo Xiong
- Department of Chemistry
- University of California
- Davis
- USA
| | | | - Cheuk-Yiu Ng
- Department of Chemistry
- University of California
- Davis
- USA
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