1
|
Yang T, Li A, Chen GK, Yao Q, Suits AG, Guo H, Hudson ER, Campbell WC. Isomer-specific kinetics of the C + + H 2O reaction at the temperature of interstellar clouds. SCIENCE ADVANCES 2021; 7:7/2/eabe4080. [PMID: 33523979 PMCID: PMC7787479 DOI: 10.1126/sciadv.abe4080] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/12/2020] [Indexed: 06/12/2023]
Abstract
The reaction C+ + H2O → HCO+/HOC+ + H is one of the most important astrophysical sources of HOC+ ions, considered a marker for interstellar molecular clouds exposed to intense ultraviolet or x-ray radiation. Despite much study, there is no consensus on rate constants for formation of the formyl ion isomers in this reaction. This is largely due to difficulties in laboratory study of ion-molecule reactions under relevant conditions. Here, we use a novel experimental platform combining a cryogenic buffer-gas beam with an integrated, laser-cooled ion trap and high-resolution time-of-flight mass spectrometer to probe this reaction at the temperature of cold interstellar clouds. We report a reaction rate constant of k = 7.7(6) × 10-9 cm3 s-1 and a branching ratio of formation η = HOC+/HCO+ = 2.1(4). Theoretical calculations suggest that this branching ratio is due to the predominant formation of HOC+ followed by isomerization of products with internal energy over the isomerization barrier.
Collapse
Affiliation(s)
- Tiangang Yang
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, P. R. China
| | - Anyang Li
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, P. R. China
| | - Gary K Chen
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Qian Yao
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Arthur G Suits
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
| | - Hua Guo
- Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, NM 87131, USA.
| | - Eric R Hudson
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA.
- UCLA Center for Quantum Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Wesley C Campbell
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095, USA.
- UCLA Center for Quantum Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| |
Collapse
|
2
|
Woon DE. Quantum chemical protocols for modeling reactions and spectra in astrophysical ice analogs: the challenging case of the C⁺ + H₂O reaction in icy grain mantles. Phys Chem Chem Phys 2015; 17:28705-18. [PMID: 26445904 DOI: 10.1039/c5cp03393d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Icy grain mantles that accrete on refractory dust particles in the very cold interstellar medium or beyond the snow line in protoplanetary disks serve as minute incubators for heterogeneous chemistry. Ice mantle chemistry can differ significantly from the gas phase chemistry that occurs in these environments and is often richer. Modeling ices and their chemistry is a challenging task for quantum theoretical methods, but theory promises insight into these systems that is difficult to attain with experiments. Density functional theory (DFT) is predominately employed for modeling reactions in icy grain mantles due to its favorable scalability, but DFT has limitations that risk undercutting its reliability for this task. In this work, basic protocols are proposed for identifying the degree to which DFT methods are able to reproduce experimental or higher level theoretical results for the fundamental interactions upon which ice mantle chemistry depends, including both reactive interactions and non-reactive scaffolding interactions. The exemplar of this study is the reaction of C(+) with H2O, where substantial methodological differences are found in the prediction of gas phase relative energetics for stationary points (about 10 kcal mol(-1) for the C-O bond energy of the H2OC(+) intermediate), which in turn casts doubt about employing it to treat the C(+) + H2O reaction on an ice surface. However, careful explorations demonstrate that B3LYP with small correlation consistent basis sets performs in a sufficiently reliable manner to justify using it to identify plausible chemical pathways, where the dominant products were found to be neutral HOC and the CO(-) anion plus one and two H3O(+) cations, respectively. Predicted vibrational and electronic spectra are presented that would serve to verify or disconfirm the pathways; the latter were computed with time-dependent DFT. Conclusions are compared with those of a recent similar study by McBride and coworkers (J. Phys. Chem. A, 2014, 118, 6991).
Collapse
Affiliation(s)
- David E Woon
- Department of Chemistry, University of Illinois at Urbana-Champaign, Box 92-6, CLSL, 600 S. Mathews, Urbana, IL 61801, USA.
| |
Collapse
|
3
|
Carrascosa E, Bawart M, Stei M, Linden F, Carelli F, Meyer J, Geppert WD, Gianturco FA, Wester R. Nucleophilic substitution with two reactive centers: The CN(-) + CH3I case. J Chem Phys 2015; 143:184309. [PMID: 26567664 DOI: 10.1063/1.4934993] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The nucleophilic substitution reaction CN(-) + CH3I allows for two possible reactive approaches of the reactant ion onto the methyl halide, which lead to two different product isomers. Stationary point calculations predict a similar shape of the potential and a dominant collinear approach for both attacks. In addition, an H-bonded pre-reaction complex is identified as a possible intermediate structure. Submerged potential energy barriers hint at a statistical formation process of both CNCH3 and NCCH3 isomers at the experimental collision energies. Experimental angle- and energy differential cross sections show dominant direct rebound dynamics and high internal excitation of the neutral product. No distinct bimodal distributions can be extracted from the velocity images, which impedes the indication of a specific preference towards any of the product isomers. A forward scattering simulation based on the experimental parameters describes accurately the experimental outcome and shows how the possibility to discriminate between the two isomers is mainly hindered by the large product internal excitation.
Collapse
Affiliation(s)
- E Carrascosa
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - M Bawart
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - M Stei
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - F Linden
- Department of Physics, AlbaNova, Stockholm University, 10691 Stockholm, Sweden
| | - F Carelli
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - J Meyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - W D Geppert
- Department of Physics, AlbaNova, Stockholm University, 10691 Stockholm, Sweden
| | - F A Gianturco
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - R Wester
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| |
Collapse
|
4
|
Carrascosa E, Stei M, Kainz MA, Wester R. Isomer-specific product formation in the proton transfer reaction of HOCO+with CO. Mol Phys 2015. [DOI: 10.1080/00268976.2015.1075620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
5
|
Morgan WJ, Fortenberry RC. Quartic force fields for excited electronic states: rovibronic reference data for the 1 (2)A' and 1 (2)A″ states of the isoformyl radical, HOC. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 135:965-972. [PMID: 25168234 DOI: 10.1016/j.saa.2014.07.082] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 07/23/2014] [Accepted: 07/28/2014] [Indexed: 06/03/2023]
Abstract
Quartic force fields (QFFs) have been shown to be an effective, accurate, and relatively compact means of computing rovibrational spectroscopic data for numerous molecules with numerous applications. However, excited states have been nearly excluded from the this approach since most accurate QFFs are based on the "gold standard" coupled cluster singles, doubles, and perturbative triples [CCSD(T)] method which is not readily extended to excited states. In this work, rovibronic spectroscopic data is provided for the isoformyl radical, a molecule of significance in combustion and astrochemistry, both through the traditional means of variational access to excited states with CCSD(T) and in the novel extension of QFFs routinely to treat electronically excited states through the standard coupled cluster excited state approach, equation of motion (EOM) CCSD. It is shown here that the new EOM-based QFF provides structural parameters and rotational constants that are quite close to those from a related CCSD(T)-based QFF for the 1 (2)A(″) excited state of HOC. The anharmonic vibrational frequency percent differences between the two QFFs are less than 0.4% for the O-H stretch, less than 1.9% for the C-O stretch, and around 3.0% for the bend. Even so, the pure excited state EOM-QFF anharmonic frequencies are still very good abinitio representations that may be applied to systems where electronically excited states are not variationally accessible. Additionally, rovibrational spectroscopic data is provided for the 1 (2)A(') ground state of HOC and for both the ground and excited state of DOC.
Collapse
Affiliation(s)
- W James Morgan
- Georgia Southern University, Department of Chemistry, Statesboro, GA 30460, USA
| | - Ryan C Fortenberry
- Georgia Southern University, Department of Chemistry, Statesboro, GA 30460, USA.
| |
Collapse
|
6
|
McBride EJ, Millar TJ, Kohanoff JJ. Irradiation of water ice by C(+) ions in the cosmic environment. J Phys Chem A 2014; 118:6991-8. [PMID: 25090372 DOI: 10.1021/jp502738x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We present a first-principles MD (FPMD) study of the interaction of low-energy, positively charged carbon (C(+)) projectiles with amorphous solid water clusters at 30 K. Reactions involving the carbon ion at an initial energy of 11 and 1.7 eV with a 30-molecule cluster have been investigated. Simulations indicate that the neutral isoformyl radical, COH(•), and carbon monoxide, CO, are the dominant products of these reactions. All of these reactions are accompanied by the transfer of a proton from the reacting water molecule to the ice, where it forms a hydronium ion. We find that COH(•) is formed either via a direct, “knock-out”, mechanism following the impact of the C(+) projectile upon a water molecule or by creation of a COH2(+) intermediate. The direct mechanism is more prominent at higher energies. CO is generally produced following the dissociation of COH(•). More frequent production of the formyl radical, HCO(•), is observed here than in gas-phase calculations. A less commonly occurring product is the dihydroxymethyl, CH(OH)2(•), radical. Although a minor result, its existence gives an indication of the increasing chemical complexity that is possible in such heterogeneous environments.
Collapse
Affiliation(s)
- E J McBride
- Atomistic Simulation Centre, ¶Astrophysics Research Centre, and †School of Mathematics and Physics, Queen's University Belfast , Belfast BT7 1NN, Northern Ireland, United Kingdom
| | | | | |
Collapse
|
7
|
Flores J. Further quasi-classical trajectory studies on the C++ H2O reaction. MOLECULAR SIMULATION 2009. [DOI: 10.1080/08927020802430760] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
8
|
Flores JR, González AB. The role of the excited electronic states in the C+ + H2O reaction. J Chem Phys 2008; 128:144310. [PMID: 18412448 DOI: 10.1063/1.2903465] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The electronic excited states of the [COH2]+ system have been studied in order to establish their role in the dynamics of the C+ + H2O-->[COH]+ +H reaction, which is a prototypical ion-molecule reaction. The most relevant minima and saddle points of the lowest excited state have been determined and energy profiles for the lowest excited doublet and quartet electronic states have been computed along the fragmentation and isomerization coordinates. Also, nonadiabatic coupling strengths between the ground and the first excited state have been computed where they can be large. Our analysis suggests that the first excited state could play an important role in the generation of the formyl isomer, which has been detected in crossed beam experiments [D. M. Sonnenfroh et al., J. Chem. Phys. 83, 3985 (1985)], but could not be explained in quasiclassical trajectory computations [Y. Ishikawa et al., Chem. Phys. Lett. 370, 490 (2003); J. R. Flores, J. Chem. Phys. 125, 164309 (2006)].
Collapse
Affiliation(s)
- Jesús R Flores
- Facultad de Química, Universidad de Vigo, E-36200 Vigo, Spain.
| | | |
Collapse
|
9
|
Flores JR. Quasiclassical trajectories on a finite element density functional potential energy surface: The C++H2O reaction revisited. J Chem Phys 2006; 125:164309. [PMID: 17092075 DOI: 10.1063/1.2359726] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new method for the representation of potential energy surfaces (PESs) based on the p version of the finite element method is presented and applied to the PES of the [COH2]+ system in order to study the C++H2O-->[COH]++H reaction through the quasiclassical trajectory method. Benchmark ab initio computations have been performed on the most relevant stationary points of the PES through a procedure that incorporates basis set extrapolations, the contribution of the core correlation energy, and scalar relativistic corrections. The electronic structure method employed to compute the many points needed to construct the PES is a hybrid density functional approach of the B3LYP type with geometry-dependent parameters, which improves dramatically the performance with respect of the B3LYP method. The trajectory computations shed light on the behavior of the COH2+ complex formed in the collision. At a fixed relative translational energy of 0.62 eV, which corresponds to the crossed beam experiments [D. M. Sonnenfroh et al., J. Chem. Phys. 83, 3985 (1985)], the complex dissociates significantly into the reactants (37%). However, the behavior for a thermal sampling at T=300 K is significantly different because only 9% of the trajectories where capture occurs lead to dissociation into the reactants. The latter kind of behavior is coherent with the view that simple ion-molecule reactions proceed quite often at the capture rate provided it is corrected by the fraction of the electronic states which, being nearly degenerate for the reactants, become attractive at short distances. For both T=300 K and crossed beam conditions, the trajectory computations indicate that COH2+ is the critical intermediate, in agreement with a recent work [Y. Ishikawa et al., Chem. Phys. Lett. 370, 490 (2003)] and in contrast with the interpretation of the crossed beam experiments. Besides, virtually all trajectories generate COH++H (>99%), but a significant proportion of the isoformyl cation is formed with enough vibrational energy as to surmount the COH+-HCO+ isomerization barrier, about 37% at T=300 K.
Collapse
Affiliation(s)
- Jesús R Flores
- Departamento de Química Física, Facultad de Química, Universidad de Vigo, E-36200 Vigo, Spain.
| |
Collapse
|
10
|
Ishikawa Y, Ikegami T, Binning R. Direct ab initio molecular dynamics study of C++H2O: angular distribution of products and distribution of product kinetic energies. Chem Phys Lett 2003. [DOI: 10.1016/s0009-2614(03)00079-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
11
|
|
12
|
Chiu YH, Dressler RA, Levandier DJ, Williams S, Murad E. Guided-ion beam study of the O2++C2H2 charge-transfer and chemical reaction channels. J Chem Phys 1999. [DOI: 10.1063/1.478312] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
13
|
Chiu YH, Dressler RA, Levandier DJ, Williams S, Murad E. Collision energy dependence and product recoil velocity analysis of O+(4S)+C2H2 charge-transfer and chemical reaction channels. J Chem Phys 1998. [DOI: 10.1063/1.477148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
14
|
Sonnenfroh DM, Farrar JM. Dynamics of the condensation reactions of C+with C2H4and C2H2. J Chem Phys 1988. [DOI: 10.1063/1.455390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
15
|
Creasy WR, Farrar JM. Reactive scattering from double minimum potentials: Li+ catalyzed elimination reactions of alkyl halides. J Chem Phys 1987. [DOI: 10.1063/1.453645] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
16
|
Sonnenfroh DM, Farrar JM. Collision complexes in the reactions of CH+3 with C2H4 and C2H2. J Chem Phys 1986. [DOI: 10.1063/1.451350] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
17
|
Creasy WR, Farrar JM. Reactive scattering from double minimum potentials: Energetics and mechanism of the gas phase dehydration reaction of lithium ion withtert‐butyl alcohol. J Chem Phys 1986. [DOI: 10.1063/1.451634] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
18
|
Curtis RA, Farrar JM. C–N bond formation in the gas phase reaction of C+ with NH3. J Chem Phys 1986. [DOI: 10.1063/1.450187] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|