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Crane SW, Lee JWL, Ashfold MNR, Rolles D. Molecular photodissociation dynamics revealed by Coulomb explosion imaging. Phys Chem Chem Phys 2023. [PMID: 37335247 DOI: 10.1039/d3cp01740k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Coulomb explosion imaging (CEI) methods are finding ever-growing use as a means of exploring and distinguishing the static stereo-configurations of small quantum systems (molecules, clusters, etc). CEI experiments initiated by ultrafast (femtosecond-duration) laser pulses also allow opportunities to track the time-evolution of molecular structures, and thereby advance understanding of molecular fragmentation processes. This Perspective illustrates two emerging families of dynamical studies. 'One-colour' studies (employing strong field ionisation driven by intense near infrared or single X-ray or extreme ultraviolet laser pulses) afford routes to preparing multiply charged molecular cations and exploring how their fragmentation progresses from valence-dominated to Coulomb-dominated dynamics with increasing charge and how this evolution varies with molecular size and composition. 'Two-colour' studies use one ultrashort laser pulse to create electronically excited neutral molecules (or monocations), whose structural evolution is then probed as a function of pump-probe delay using an ultrafast ionisation pulse along with time and position-sensitive detection methods. This latter type of experiment has the potential to return new insights into not just molecular fragmentation processes but also charge transfer processes between moieties separating with much better defined stereochemical control than in contemporary ion-atom and ion-molecule charge transfer studies.
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Affiliation(s)
- Stuart W Crane
- School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
| | - Jason W L Lee
- Department of Chemistry, University of Oxford, Oxford, OX1 3TA, UK
| | | | - Daniel Rolles
- J.R. Macdonald Laboratory, Department of Physics, Kansas State University, Manhattan, KS 66506, USA
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Mogyorosi K, Sarosi K, Chikan V. Direct Production of CH(A 2Δ) Radical from Intense Femtosecond Near-IR Laser Pulses. J Phys Chem A 2020; 124:8112-8119. [PMID: 32902281 DOI: 10.1021/acs.jpca.0c05206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CH(A2Δ) radical formation was observed in bromoform and methanol vapor in argon plasma with near-infrared femtosecond laser pulses (43 fs, 1030 nm, 100 kHz, 250 μJ/pulse). The beam was focused with an achromatic lens, creating very high intensity in the plasma that caused Coulomb explosion (calculated intensity was ∼1.1 × 1016 W/cm2 in the focal point). The emitted fluorescence light was measured with high spectral (1-10 cm-1) and temporal resolution (5 ns) with an FT-Vis spectrometer. The step-scan technique allowed the reconstruction of the time-resolved fluorescence spectra from CH(A-X) emission. The emission from atomic lines such as H, Br, C, and O was observed and also from C+ cations and CH and C2 radicals. This indicates that in a significant portion of these organic molecules, all chemical bonds were cleaved in the Coulomb explosion. For both organics, the peak maximum of the CH(A) emission occurred at about 10 ns after excitation by the femtosecond pulse. After the maximum, a rapid emission decay was observed in the case of bromoform (monoexponential decay, t = 10 ns). The fluorescence decay was biexponential when methanol was used as the source for CH(A) generation. It can be assumed that CH(A) generation involved a fast and a slower path with some secondary reactions via the stepwise loss of hydrogen atoms from the CH3 group. The time constants were t1 = 7.8-8.3 ns and t2 = 78-82 ns for the fast and slow components, respectively, and very similar values were obtained at 10 and 25 mbar total pressures. However, in the case of bromoform, the C-Br bonds are significantly weaker; therefore, these atoms can be removed even in a single step via multiphoton absorption. The rotational temperature of CH(A) radicals generated from methanol decreased rapidly in the 30-55 ns time period from 2770 ± 80 to 1530 ± 50 K. The vibrational temperature increased from 3530 ± 450 to 9810 ± 760 K in the 30-80 ns time period and then started to decrease (the average temperatures were Trot = 910 ± 20 K and Tvib = 7490 ± 340 K at 100 ns). This initial increase of Tvib is thought to be the result of electron collision with the CH radicals. The high temperatures of the fragment may indicate the roaming reaction associated with the Coulomb explosion of the parent molecule. We demonstrated that CH(A) radicals can be produced from both organic compounds, and the step-scan technique is ideal for the characterization of their time-resolved spectra using the 100 kHz high repetition rate near-infrared femtosecond laser pulses. The FT/UV-vis step-scan technique can detect neutral species directly with high spectral and time resolution, thus it is a complementary technique to the experiments utilizing ion detection schemes, such as velocity map imaging.
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Affiliation(s)
- K Mogyorosi
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner u. 3. H-6728 Szeged, Hungary
| | - K Sarosi
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner u. 3. H-6728 Szeged, Hungary
| | - V Chikan
- ELI-ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner u. 3. H-6728 Szeged, Hungary.,Department of Chemistry, Kansas State University, 213 CBC Building, Manhattan, Kansas 66506-0401, United States
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Wu H, Xue Y, Wen J, Wang H, Bai L, He W, Sun R, Zheng W. BrCl+ elimination from Coulomb explosion of 1,2-bromochloroethane induced by intense femtosecond laser fields. RSC Adv 2019; 9:31853-31859. [PMID: 35530799 PMCID: PMC9072746 DOI: 10.1039/c9ra07498h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 10/03/2019] [Indexed: 12/14/2022] Open
Abstract
By using a dc-slice imaging technique, photodissociation of 1,2-C2H4BrCl was investigated at 800 nm looking for heteronuclear unimolecular ion elimination of BrCl+ in an 80 fs laser field. The occurrence of fragment ion BrCl+ in the mass spectrum verified the existence of a unimolecular decomposition channel of BrCl+ in this experiment. The relative quantum yield of the BrCl+ channel was measured to be 0.8%. By processing and analyzing the velocity and angular distributions obtained from the corresponding sliced images of BrCl+ and its partner ion C2H4+, we concluded that BrCl+ came from Coulomb explosion of the 1,2-bromochloroethane dication 1,2-C2H4BrCl2+. With the aid of quantum chemical calculations at the M06-2X/def2-TZVP level, the potential energy surface for BrCl+ detachment from 1,2-C2H4BrCl2+ has been examined in detail. According to the ab initio calculations, two transition state structures tended to correlate with the reactant 1,2-C2H4BrCl2+ and the products BrCl+ + C2H4+. In this entire dissociation process, the C–Br and C–Cl bond lengths were observed to elongate asymmetrically, that is, the C–Br chemical bond broke firstly, and subsequently a new Br–Cl chemical bond started to emerge while the C–Cl bond continued to exist for a while. Hence, an asynchronous concerted elimination mechanism was favored for BrCl+ detachment. Concerted elimination of the molecular ion BrCl+ from Coulomb explosion of 1,2-bromochloroethane was studied theoretically and experimentally.![]()
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Affiliation(s)
- Hua Wu
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Yuanxin Xue
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Junqing Wen
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Hui Wang
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Lihua Bai
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Wanlin He
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Ruijuan Sun
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
| | - Wenli Zheng
- School of Sciences
- Xi'an Shiyou University
- Shanxi 710065
- P. R. China
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Yatsuhashi T, Nakashima N. Multiple ionization and Coulomb explosion of molecules, molecular complexes, clusters and solid surfaces. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2018. [DOI: 10.1016/j.jphotochemrev.2017.12.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Chatterley AS, Lackner F, Neumark DM, Leone SR, Gessner O. Tracking dissociation dynamics of strong-field ionized 1,2-dibromoethane with femtosecond XUV transient absorption spectroscopy. Phys Chem Chem Phys 2016; 18:14644-53. [DOI: 10.1039/c6cp02598f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using femtosecond time-resolved extreme ultraviolet absorption spectroscopy, the dissociation dynamics of the haloalkane 1,2-dibromoethane (DBE) have been explored following strong field ionization by femtosecond near infrared pulses at intensities between 7.5 × 1013 and 2.2 × 1014 W cm−2.
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Affiliation(s)
- Adam S. Chatterley
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
| | - Florian Lackner
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
| | - Daniel M. Neumark
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
| | - Stephen R. Leone
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
- Department of Chemistry
| | - Oliver Gessner
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
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Wu H, Zhang S, Zhang J, Yang Y, Deng L, Jia T, Wang Z, Sun Z. Observation of Hydrogen Migration in Cyclohexane under an Intense Femtosecond Laser Field. J Phys Chem A 2015; 119:2052-7. [DOI: 10.1021/jp510667z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Hua Wu
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Shian Zhang
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Jian Zhang
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Yan Yang
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Li Deng
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Tianqing Jia
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Zugeng Wang
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Zhenrong Sun
- State Key Laboratory of Precision
Spectroscopy and Department of Physics, East China Normal University, Shanghai 200062, P. R. China
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Teng C, Wu H, Zhang J, Yang Y, Jia T, Zhang S, Sun Z. Dissociative ionization and Coulomb explosion of ethyl bromide under a near-infrared intense femtosecond laser field. RSC Adv 2015. [DOI: 10.1039/c5ra02383a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The dissociation pathways for H2 and H2+ elimination from the parent ions C2H5Br+ and C2H5Br2+ are theoretically and experimentally demonstrated.
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Affiliation(s)
- Chong Teng
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Hua Wu
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Jian Zhang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Yan Yang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Tianqing Jia
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Shian Zhang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062
- People's Republic of China
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Wu H, Zhang S, Yang Y, Sun S, Zhang J, Deng L, Jia T, Wang Z, Sun Z. Coulomb explosion and dissociative ionization of 1,2-dibromoethane under an intense femtosecond laser field. RSC Adv 2014. [DOI: 10.1039/c4ra06121g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Coulomb explosion and dissociative ionization of 1,2-dibromoethane are experimentally investigated in a near-infrared (800 nm) femtosecond laser field by dc-slice imaging technology.
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Affiliation(s)
- Hua Wu
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Shian Zhang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Yan Yang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
- State Key Laboratory of High Field Laser Physics
| | - Shengzhi Sun
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Jian Zhang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Li Deng
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Tianqing Jia
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Zugeng Wang
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy
- Department of Physics
- East China Normal University
- Shanghai 200062, P. R. China
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