1
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Wu Z, Walser S, Podlesnic V, Isaza-Monsalve M, Mattivi E, Mu G, Nardi R, Gniewek P, Tomza M, Furey BJ, Schindler P. Photodissociation spectra of single trapped CaOH+ molecular ions. J Chem Phys 2024; 161:044304. [PMID: 39037137 DOI: 10.1063/5.0217685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 07/08/2024] [Indexed: 07/23/2024] Open
Abstract
Molecular ions that are generated by chemical reactions with trapped atomic ions can serve as an accessible testbed for developing molecular quantum technologies. On the other hand, they are also a hindrance to scaling up quantum computers based on atomic ions, as unavoidable reactions with background gases destroy the information carriers. Here, we investigate the single- and two-photon dissociation processes of single CaOH+ molecular ions co-trapped in Ca+ ion crystals using a femtosecond laser system. We report the photodissociation cross section spectra of CaOH+ for single-photon processes at λ = 245-275 nm and for two-photon processes at λ = 500-540 nm. Measurements are interpreted with quantum-chemical calculations, which predict the photodissociation threshold for CaOH+ → Ca+ + OH at 265 nm. This result can serve as a basis for dissociation-based spectroscopy for studying the internal structure of CaOH+. The result also gives a prescription for recycling Ca+ ions in large-scale trapped Ca+ quantum experiments from undesired CaOH+ ions formed in the presence of background water vapor.
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Affiliation(s)
- Zhenlin Wu
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Stefan Walser
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Verena Podlesnic
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Mariano Isaza-Monsalve
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Elyas Mattivi
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Guanqun Mu
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - René Nardi
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Piotr Gniewek
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Michał Tomza
- Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw, Poland
| | - Brandon J Furey
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
| | - Philipp Schindler
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25/4, 6020 Innsbruck, Austria
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2
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Yang Z, Cao F, Cheng H, Liu S, Sun J. A Globally Accurate Neural Network Potential Energy Surface and Quantum Dynamics Studies on Be +( 2S) + H 2/D 2 → BeH +/BeD + + H/D Reactions. Molecules 2024; 29:3436. [PMID: 39065017 DOI: 10.3390/molecules29143436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2024] [Revised: 07/18/2024] [Accepted: 07/20/2024] [Indexed: 07/28/2024] Open
Abstract
Chemical reactions between Be+ ions and H2 molecules have significance in the fields of ultracold chemistry and astrophysics, but the corresponding dynamics studies on the ground-state reaction have not been reported because of the lack of a global potential energy surface (PES). Herein, a globally accurate ground-state BeH2+ PES is constructed using the neural network model based on 18,657 ab initio points calculated by the multi-reference configuration interaction method with the aug-cc-PVQZ basis set. On the newly constructed PES, the state-to-state quantum dynamics calculations of the Be+(2S) + H2(v0 = 0; j0 = 0) and Be+(2S) + D2(v0 = 0; j0 = 0) reactions are performed using the time-dependent wave packet method. The calculated results suggest that the two reactions are dominated by the complex-forming mechanism and the direct abstraction process at relatively low and high collision energies, respectively, and the isotope substitution has little effect on the reaction dynamics characteristics. The new PES can be used to further study the reaction dynamics of the BeH2+ system, such as the effects of rovibrational excitations and alignment of reactant molecules, and the present dynamics data could provide an important reference for further experimental studies at a finer level.
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Affiliation(s)
- Zijiang Yang
- School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
| | - Furong Cao
- School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
| | - Huiying Cheng
- School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
| | - Siwen Liu
- School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
| | - Jingchang Sun
- School of Physics and Electronic Technology, Liaoning Normal University, Dalian 116029, China
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3
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Calvin A, Eierman S, Peng Z, Brzeczek M, Satterthwaite L, Patterson D. Single molecule infrared spectroscopy in the gas phase. Nature 2023; 621:295-299. [PMID: 37380028 PMCID: PMC10499601 DOI: 10.1038/s41586-023-06351-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 06/21/2023] [Indexed: 06/30/2023]
Abstract
Spectroscopy is a key analytical tool that provides valuable insight into molecular structure and is widely used to identify chemical samples. Tagging spectroscopy is a form of action spectroscopy in which the absorption of a single photon by a molecular ion is detected via the loss of a weakly attached, inert 'tag' particle (for example, He, Ne, N2)1-3. The absorption spectrum is derived from the tag loss rate as a function of incident radiation frequency. So far, all spectroscopy of gas phase polyatomic molecules has been restricted to large molecular ensembles, thus complicating spectral interpretation by the presence of multiple chemical and isomeric species. Here we present a novel tagging spectroscopic scheme to analyse the purest possible sample: a single gas phase molecule. We demonstrate this technique with the measurement of the infrared spectrum of a single gas phase tropylium (C7H7+) molecular ion. The high sensitivity of our method revealed spectral features not previously observed using traditional tagging methods4. Our approach, in principle, enables analysis of multicomponent mixtures by identifying constituent molecules one at a time. Single molecule sensitivity extends action spectroscopy to rare samples, such as those of extraterrestrial origin5,6, or to reactive reaction intermediates formed at number densities that are too low for traditional action methods.
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Affiliation(s)
- Aaron Calvin
- Department of Physics, University of California, Santa Barbara, CA, USA
| | - Scott Eierman
- Department of Physics, University of California, Santa Barbara, CA, USA
| | - Zeyun Peng
- Department of Physics, University of California, Santa Barbara, CA, USA
| | - Merrell Brzeczek
- Department of Physics, University of California, Santa Barbara, CA, USA
| | - Lincoln Satterthwaite
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA, USA
| | - David Patterson
- Department of Physics, University of California, Santa Barbara, CA, USA.
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4
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He D, Li W, Li Q, Chen S, Wang L, Liu Y, Wang M. The impact of non-adiabatic effects on reaction dynamics: a study based on the adiabatic and non-adiabatic potential energy surfaces of CaH 2. Phys Chem Chem Phys 2023; 25:22744-22754. [PMID: 37605513 DOI: 10.1039/d3cp02416d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
The two-state non-adiabatic potential energy matrices of the CaH2+ system are calculated via a diabatization approach by using a neural network model. Subsequently, the adiabatic and non-adiabatic potential energy surfaces (PESs) are constructed based on these non-adiabatic potential energy matrices. Furthermore, based on the adiabatic and non-adiabatic PESs, the Ca+(4s2S) + H2(X1Σ+g) → H(2S) + CaH+(X1Σ+) reaction is studied using the time-dependent wave packet method. Comparative analysis of the experimental and theoretical integral reaction cross-sections (ICSs) indicates that the maximum deviation between the results obtained from the adiabatic PES and the corresponding experimental value is 12.7 bohr2; in contrast, the maximum discrepancy between the theoretical result derived from the non-adiabatic PES and the experimental value is merely 0.42 bohr2. The potential well along the reaction path acts as a 'filter', selectively guiding intermediates with longer lifetimes in the potential well back to the reactant channel. This phenomenon indicates that the non-adiabatic effects significantly influence the reaction dynamics of the CaH2+ system.
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Affiliation(s)
- Di He
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
| | - Wentao Li
- Weifang University of Science and Technology, Shouguang 262700, China
| | - Quanjiang Li
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
| | - Shenghui Chen
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
| | - Li Wang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
| | - Yanli Liu
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
| | - Meishan Wang
- School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264025, China.
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5
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Yang Z, Chen H, Mao Y, Chen M. Neural network potential energy surface and quantum dynamics studies for the Ca +( 2S) + H 2 → CaH + + H reaction. Phys Chem Chem Phys 2022; 24:19209-19217. [DOI: 10.1039/d2cp02711a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reactive collisions of Ca+ ion with H2 molecule play a crucial role in ultracold chemistry, quantum information and other cutting-edge fields, and have been widely concerned experimentally, but the corresponding...
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6
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Greenberg J, Schmid PC, Thorpe JH, Nguyen TL, Catani KJ, Krohn OA, Miller MI, Stanton JF, Lewandowski HJ. Using isotopologues to probe the potential energy surface of reactions of C 2H 2 ++C 3H 4. J Chem Phys 2021; 154:124310. [PMID: 33810655 DOI: 10.1063/5.0046438] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Investigations into bimolecular reaction kinetics probe the details of the underlying potential energy surface (PES), which can help to validate high-level quantum chemical calculations. We utilize a combined linear Paul ion trap with a time-of-flight mass spectrometer to study isotopologue reactions between acetylene cations (C2H2 +) and two isomers of C3H4: propyne (HC3H3) and allene (H2C3H2). In a previous study [Schmid et al., Phys. Chem. Chem. Phys. 22, 20303 (2020)],1 we showed that the two isomers of C3H4 have fundamentally different reaction mechanisms. Here, we further explore the calculated PES by isotope substitution. While isotopic substitution of reactants is a standard experimental tool in the investigation of molecular reaction kinetics, the controlled environment of co-trapped, laser-cooled Ca+ ions allows the different isotopic reaction pathways to be followed in greater detail. We report branching ratios for all of the primary products of the different isotopic species. The results validate the previously proposed mechanism: propyne forms a bound reaction complex with C2H2 +, while allene and C2H2 + perform long-range charge exchange only.
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Affiliation(s)
- James Greenberg
- Department of Physics, University of Colorado, 390 UCB, Boulder, Colorado 80309, USA
| | - Philipp C Schmid
- Department of Physics, University of Colorado, 390 UCB, Boulder, Colorado 80309, USA
| | - James H Thorpe
- Quantum Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, Florida 32611, USA
| | - Thanh L Nguyen
- Quantum Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, Florida 32611, USA
| | - Katherine J Catani
- Department of Physics, University of Colorado, 390 UCB, Boulder, Colorado 80309, USA
| | - Olivia A Krohn
- Department of Physics, University of Colorado, 390 UCB, Boulder, Colorado 80309, USA
| | - Mikhail I Miller
- Department of Physics, University of Colorado, 390 UCB, Boulder, Colorado 80309, USA
| | - John F Stanton
- Quantum Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, Florida 32611, USA
| | - H J Lewandowski
- Department of Physics, University of Colorado, 390 UCB, Boulder, Colorado 80309, USA
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7
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Yang Z, Mao Y, Chen M. Quantum Dynamics Studies of the Significant Intramolecular Isotope Effects on the Nonadiabatic Be +( 2P) + HD → BeH +/BeD + + D/H Reaction. J Phys Chem A 2021; 125:235-242. [PMID: 33369408 DOI: 10.1021/acs.jpca.0c09593] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Quantum time-dependent wave packet dynamics studies on the nonadiabatic Be+(2P) + HD → BeH+/BeD+ + D/H reaction are performed for the first time employing recently constructed diabatic potential energy surfaces. Strong intramolecular isotope effects and unusual results are presented, which are attributed to the dynamic effects of shallow wells induced by avoided crossing on the diagonal V22d surface. The BeH+ + D and BeD+ + H channels are dominated by high-J and low-J partial waves, respectively. The BeD+/BeH+ branching ratio is larger than 10 at low energy and gradually decreases with increasing collision energy. The BeH+ product is primarily distributed at low vibrational states, whereas there exists an obvious population inversion of vibrational states on the BeD+ product. The results of differential cross sections suggest that the formation of the BeH+ + D channel favors a direct reaction process, while the BeD+ + H channel is mainly generated by the complex-forming mechanism.
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Affiliation(s)
- Zijiang Yang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
| | - Ye Mao
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
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8
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Mao Y, Yuan J, Yang Z, Chen M. Quantum dynamics studies of isotope effects in the Mg +(3p) + HD → MgH +/MgD + + D/H insertion reaction. Sci Rep 2020; 10:3410. [PMID: 32098984 PMCID: PMC7042225 DOI: 10.1038/s41598-020-60033-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 02/03/2020] [Indexed: 11/17/2022] Open
Abstract
The time-dependent wave packet quantum dynamics studies for the Mg+(3p) + HD → MgH+/MgD+ + D/H diabatic reaction are carried out for the first time on recently developed diabatic YHWCH potential energy surfaces [Phys. Chem. Chem. Phys., 2018, 20, 6638-6647]. The results of reaction probabilities and total integral cross sections show a dramatic preference to the formation of MgD+ over MgH+ owing to the insertion reaction mechanism in the title reaction. The MgD+/MgH+ branching ratio witnesses a monotonic decrease from 10.58 to 3.88 at collision energy range of 0.01 to 0.20 eV, and at the collision energy of 0.114 eV, it is close to the experimental value of 5. The rovibrational state-resolved ICSs of the two channels show the products MgD+ have higher vibrational excitation and hotter rotational state distributions. The opacity function P(J) suggests that the MgH+ + D channel and MgD+ + H channel are dominated by high-b and low-b collisions, respectively. Both forward and backward scattering peaks are found in the differential cross section curves, whereas the angle distributions of products are not strictly forward-backward symmetric because of the short lifetime of the complex in the reaction.
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Affiliation(s)
- Ye Mao
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, 116024, PR China
| | - Jiuchuang Yuan
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, 116024, PR China
| | - Zijiang Yang
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, 116024, PR China
| | - Maodu Chen
- Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian, 116024, PR China.
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9
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Schmid PC, Greenberg J, Nguyen TL, Thorpe JH, Catani KJ, Krohn OA, Miller MI, Stanton JF, Lewandowski HJ. Isomer-selected ion–molecule reactions of acetylene cations with propyne and allene. Phys Chem Chem Phys 2020; 22:20303-20310. [DOI: 10.1039/d0cp03953e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combined experimental and quantum chemistry study between sympathetically cooled acetylene cations and propyne or allene explains the dramatically different reaction mechanisms.
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Affiliation(s)
- P. C. Schmid
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
- I. Physikalisches Institut
| | - J. Greenberg
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | - T. L. Nguyen
- Quantum Theory Project
- Departments of Chemistry and Physics
- University of Florida
- Gainesville
- USA
| | - J. H. Thorpe
- Quantum Theory Project
- Departments of Chemistry and Physics
- University of Florida
- Gainesville
- USA
| | - K. J. Catani
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | - O. A. Krohn
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | - M. I. Miller
- JILA and the Department of Physics
- University of Colorado
- Boulder
- USA
| | - J. F. Stanton
- Quantum Theory Project
- Departments of Chemistry and Physics
- University of Florida
- Gainesville
- USA
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10
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Obšil P, Lešundák A, Pham T, Lakhmanskiy K, Podhora L, Oral M, Číp O, Slodička L. A room-temperature ion trapping apparatus with hydrogen partial pressure below 10 -11 mbar. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:083201. [PMID: 31472618 DOI: 10.1063/1.5104346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 08/04/2019] [Indexed: 06/10/2023]
Abstract
The lifetime of trapped ion ensembles corresponds to a crucial parameter determining the potential scalability of their prospective applications and is often limited by the achievable vacuum level in the apparatus. We report on the realization of a room-temperature 40Ca+ ion trapping vacuum apparatus with unprecedentedly low reaction rates of ions with a dominant vacuum contaminant: hydrogen. We present our trap assembly procedures and hydrogen pressure characterization by analysis of the CaH+ molecule formation rate.
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Affiliation(s)
- P Obšil
- Department of Optics, Palacký University, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - A Lešundák
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - T Pham
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - K Lakhmanskiy
- Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - L Podhora
- Department of Optics, Palacký University, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - M Oral
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - O Číp
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - L Slodička
- Department of Optics, Palacký University, 17. listopadu 12, 771 46 Olomouc, Czech Republic
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11
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Chen GK, Xie C, Yang T, Li A, Suits AG, Hudson ER, Campbell WC, Guo H. Isotope-selective chemistry in the Be +( 2S 1/2) + HOD → BeOD +/BeOH + + H/D reaction. Phys Chem Chem Phys 2019; 21:14005-14011. [PMID: 30620013 DOI: 10.1039/c8cp06690f] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Low temperature reactions between laser-cooled Be+(2S1/2) ions and partially deuterated water (HOD) molecules have been investigated using an ion trap and interpreted with zero-point corrected quasi-classical trajectory calculations on a highly accurate global potential energy surface for the ground electronic state. Both product channels have been observed for the first time, and the branching to BeOD+ + H is found to be 0.58 ± 0.14. The experimental observation is reproduced by both quasi-classical trajectory and statistical calculations. Theoretical analyses reveal that the branching to the two product channels is largely due to the availability of open states in each channel.
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Affiliation(s)
- Gary K Chen
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA.
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12
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Abstract
In this Perspective, we examine the use of laser-cooled atomic ions and sympathetically cooled molecular ions in Coulomb crystals for molecular spectroscopy. Coulomb crystals are well-isolated environments that provide localization and long storage times for sensitive measurements of weak signals and cold temperatures for precise spectroscopy. Coulomb crystals of molecular and atomic ions enable the detection of single-photon molecular ion transitions at a range of wavelengths by a change in atomic ion fluorescence at visible wavelengths. We give an overview of the state of the art from action spectroscopy to quantum logic spectroscopy for a wide range of molecular transitions from rotational sublevels separated by 10-7 cm-1 to rovibronic transitions at 25 000 cm-1. We emphasize how this system allows for unparalleled control of the molecular ion state for precision spectroscopy with applications in astrochemistry and fundamental physics. We conclude with an outlook of the use of this control in cold molecular ion reactions.
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Affiliation(s)
- Aaron T Calvin
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
| | - Kenneth R Brown
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States
- Departments of Electrical and Computer Engineering, Chemistry, and Physics , Duke University , Durham , North Carolina 27708 , United States
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13
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Condoluci J, Janardan S, Calvin AT, Rugango R, Shu G, Sherrill CD, Brown KR. Reassigning the CaH+ 11Σ → 21Σ vibronic transition with CaD+. J Chem Phys 2017; 147:214309. [DOI: 10.1063/1.5016556] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- J. Condoluci
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - S. Janardan
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - A. T. Calvin
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - R. Rugango
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - G. Shu
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - C. D. Sherrill
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - K. R. Brown
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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14
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Affiliation(s)
- Stefan Willitsch
- Department of Chemistry; University of Basel; Klingelbergstrasse 80, 4056 Basel Switzerland
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15
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Rugango R, Calvin AT, Janardan S, Shu G, Brown KR. Vibronic Spectroscopy of Sympathetically Cooled CaH
+. Chemphyschem 2016; 17:3764-3768. [DOI: 10.1002/cphc.201600645] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Indexed: 11/09/2022]
Affiliation(s)
- René Rugango
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
| | - Aaron T. Calvin
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
| | - Smitha Janardan
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
| | - Gang Shu
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
| | - Kenneth R. Brown
- School of Chemistry and Biochemistry Georgia Institute of Technology Atlanta GA 30332 USA
- Schools of Computational Science and Engineering and Physics Georgia Institute of Technology Atlanta GA 30332 USA
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16
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Khanyile NB, Shu G, Brown KR. Observation of vibrational overtones by single-molecule resonant photodissociation. Nat Commun 2015. [PMID: 26197787 PMCID: PMC4525170 DOI: 10.1038/ncomms8825] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Molecular ions can be held in a chain of laser-cooled atomic ions by sympathetic cooling. This system is ideal for performing high-precision molecular spectroscopy with applications in astrochemistry and fundamental physics. Here we show that this same system can be coupled with a broadband laser to discover new molecular transitions. We use three-ion chains of Ca+ and CaH+ to observe vibrational transitions via resonance-enhanced multiphoton dissociation detected by Ca+ fluorescence. On the basis of theoretical calculations, we assign the observed peaks to the transition from the ground vibrational state, ν=0 to ν=9 and 10. Our method allows us to track single-molecular events, and it can be extended to work with any molecule by using normal mode frequency shifts to detect the dissociation. This survey spectroscopy serves as a bridge to the precision spectroscopy required for molecular ion control. Studying the spectra of molecules typically requires large samples, which can be difficult to achieve for hard-to-generate ions. Here, the authors obtain spectra from single CaH+ molecules in a three-ion Columbic crystal, observing new molecular transitions.
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Affiliation(s)
- Ncamiso B Khanyile
- Schools of Chemistry and Biochemistry, Computational Science and Engineering, and Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| | - Gang Shu
- Schools of Chemistry and Biochemistry, Computational Science and Engineering, and Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
| | - Kenneth R Brown
- Schools of Chemistry and Biochemistry, Computational Science and Engineering, and Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
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17
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Abstract
Coulomb crystals-as a source of translationally cold, highly localized ions-are being increasingly utilized in the investigation of ion-molecule reaction dynamics in the cold regime. To develop a fundamental understanding of ion-molecule reactions, and to challenge existing models that describe the rates, product branching ratios, and temperature dependence of such processes, investigators need to exercise full control over the experimental reaction parameters. This requires not only state selection of the reactants, but also control over the collision process (e.g., the collisional energy and angular momentum) and state-selective product detection. The combination of Coulomb crystals in ion traps with cold neutral-molecule sources is enabling the measurement of state-selective reaction rates in a diverse range of systems. With the development of appropriate product detection techniques, we are moving toward the ultimate goal of examining low-energy, state-to-state ion-molecule reaction dynamics.
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Saab M, Doriol LJ, Lasorne B, Guérin S, Gatti F. A quantum dynamics study of the benzopyran ring opening guided by laser pulses. Chem Phys 2014. [DOI: 10.1016/j.chemphys.2014.01.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hansen AK, Versolato OO, Kłosowski Ł, Kristensen SB, Gingell A, Schwarz M, Windberger A, Ullrich J, López-Urrutia JRC, Drewsen M. Efficient rotational cooling of Coulomb-crystallized molecular ions by a helium buffer gas. Nature 2014; 508:76-9. [DOI: 10.1038/nature12996] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 12/19/2013] [Indexed: 01/06/2023]
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Affiliation(s)
- Mikhail Lemeshko
- a ITAMP, Harvard-Smithsonian Center for Astrophysics , Cambridge , MA , 02138 , USA
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
| | - Roman V. Krems
- c Kavli Institute for Theoretical Physics , University of California , Santa Barbara , CA , 93106 , USA
- d Department of Chemistry , University of British Columbia , BC V6T 1Z1, Vancouver , Canada
| | - John M. Doyle
- b Physics Department , Harvard University , Cambridge , MA , 02138 , USA
| | - Sabre Kais
- e Departments of Chemistry and Physics , Purdue University , West Lafayette , IN , 47907 , USA
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Versolato OO, Schwarz M, Hansen AK, Gingell AD, Windberger A, Kłosowski L, Ullrich J, Jensen F, Crespo López-Urrutia JR, Drewsen M. Decay rate measurement of the first vibrationally excited state of MgH+ in a cryogenic Paul trap. PHYSICAL REVIEW LETTERS 2013; 111:053002. [PMID: 23952392 DOI: 10.1103/physrevlett.111.053002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Indexed: 06/02/2023]
Abstract
We present a method to measure the decay rate of the first excited vibrational state of polar molecular ions that are part of a Coulomb crystal in a cryogenic linear Paul trap. Specifically, we have monitored the decay of the |ν = 1, J = 1)(X) towards the |ν = 0, J = 0)(X) level in MgH+ by saturated laser excitation of the |ν = 0, J = 2)(X)-|ν = 1, J = 1)(X) transition followed by state selective resonance enhanced two-photon dissociation out of the |ν = 0, J=2)(X) level. The experimentally observed rate of 6.32(0.69) s(-1) is in excellent agreement with the theory value of 6.13(0.03) s(-1) (this Letter). The technique enables the determination of decay rates, and thus absorption strengths, with an accuracy at the few percent level.
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Affiliation(s)
- O O Versolato
- Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg, Germany.
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