1
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Sun F, Qu Q, Li H, Jiang S, Liu Q, Ben S, Pei Y, Liang J, Wang J, Song S, Gao J, Yang W, Xu H, Wu J. All-optical steering on the proton emission in laser-induced nanoplasmas. Nat Commun 2024; 15:5150. [PMID: 38886387 PMCID: PMC11183200 DOI: 10.1038/s41467-024-49569-3] [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: 04/03/2023] [Accepted: 06/10/2024] [Indexed: 06/20/2024] Open
Abstract
Nanoplasmas induced by intense laser fields have attracted enormous attention due to their accompanied spectacular physical phenomena which are vigorously expected by the community of science and industry. For instance, the energetic electrons and ions produced in laser-driven nanoplasmas are significant for the development of compact beam sources. Nevertheless, effective confinement on the propagating charged particles, which was realized through magnetic field modulation and target structure design in big facilities, are largely absent in the microscopic regime. Here we introduce a reliable scheme to provide control on the emission direction of protons generated from surface ionization in gold nanoparticles driven by intense femtosecond laser fields. The ionization level of the nanosystem provides us a knob to manipulate the characteristics of the collective proton emission. The most probable emission direction can be precisely steered by tuning the excitation strength of the laser pulses. This work opens new avenue for controlling the ion emission in nanoplasmas and can vigorously promote the fields such as development of on-chip beam sources at micro-/nano-scales.
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Affiliation(s)
- Fenghao Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
- School of Information Science and Engineering, Harbin Institute of Technology, Weihai, 264209, China
| | - Qiwen Qu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Hui Li
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China.
| | - Shicheng Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China.
| | - Qingcao Liu
- College of Science, Harbin Institute of Technology, Weihai, 264209, China
| | - Shuai Ben
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570228, China
| | - Yu Pei
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570228, China
| | - Jiaying Liang
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570228, China
| | - Jiawei Wang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Shanshan Song
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Jian Gao
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Weifeng Yang
- School of Physics and Optoelectronic Engineering, Hainan University, Haikou, 570228, China
- Center for Theoretical Physics, Hainan University, Haikou, 570228, China
| | - Hongxing Xu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China
| | - Jian Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai, 200241, China.
- Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing, 401121, China.
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi, 030006, China.
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2
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McManus JW, Allum F, Featherstone J, Lam CS, Brouard M. Two-Dimensional Projected-Momentum Covariance Mapping for Coulomb Explosion Imaging. J Phys Chem A 2024; 128:3220-3229. [PMID: 38607425 PMCID: PMC11056990 DOI: 10.1021/acs.jpca.4c01084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/28/2024] [Accepted: 03/29/2024] [Indexed: 04/13/2024]
Abstract
We introduce projected-momentum covariance mapping, an extension of recoil-frame covariance mapping for 2D ion imaging studies. By considering the two-dimensional projection of the ion momenta as recorded by the detector, one opens the door to a complex suite of analysis tools adapted from three-dimensional momentum imaging studies. This includes the use of different frames of reference to unravel the dynamics of fragmentation and the application of fragment momentum constraints to isolate specific fragmentation channels. The technique is demonstrated on data from a two-dimensional ion imaging study of the Coulomb explosion of the cis and trans isomers of 1,2-dichloroethene, following strong-field ionization by an intense near-infrared femtosecond laser pulse. Classical simulations are used to guide the interpretation of projected-momentum covariance maps. The results offer a detailed insight into the distinct Coulomb explosion dynamics for this pair of isomers and lay the groundwork for future time-resolved studies of photoisomerization dynamics in this molecular system.
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Affiliation(s)
- Joseph W. McManus
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | | | - Josh Featherstone
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Chow-Shing Lam
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
| | - Mark Brouard
- Chemistry Research Laboratory,
Department of Chemistry, University of Oxford, Oxford OX1 3TA, U.K.
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3
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Sutton SF, Rotteger CH, Miller DM, Quiroz LM, Sen A, Tarakeshwar P, Sayres SG. Production of Metastable CO 3+ through the Strong-Field Ionization and Coulomb Explosion of Formic Acid Dimer. J Phys Chem A 2022; 126:5099-5106. [DOI: 10.1021/acs.jpca.2c02609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shaun F. Sutton
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Chase H. Rotteger
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Dane M. Miller
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Lenin M. Quiroz
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | - Ananya Sen
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
| | | | - Scott G. Sayres
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
- Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, Arizona 85287, United States
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4
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Yu X, Zhang X, Hu X, Zhao X, Ren D, Li X, Ma P, Wang C, Wu Y, Luo S, Ding D. Femtosecond Time-Resolved Neighbor Roles in the Fragmentation Dynamics of Molecules in a Dimer. PHYSICAL REVIEW LETTERS 2022; 129:023001. [PMID: 35867441 DOI: 10.1103/physrevlett.129.023001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/07/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
How the neighbor effect plays its role in the fragmentation of molecular clusters attracts great attention for physicists and chemists. Here, we study this effect in the fragmentation of N_{2}O dimer by performing three-body coincidence measurements on the femtosecond timescale. Rotations of bound N_{2}O^{+} triggered by neutral or ionic neighbors are tracked. The forbidden dissociation path between B^{2}Π and ^{4}Π is opened by the spin-exchange effect due to the existence of neighbor ions, leading to a new channel of N_{2}O^{+}→NO+N^{+} originating from B^{2}Π. The formation and dissociation of the metastable product N_{3}O_{2}^{+} from two ion-molecule reaction channels are tracked in real time, and the corresponding trajectories are captured. Our results demonstrate a significant and promising step towards the understanding of neighbor roles in the reactions within clusters.
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Affiliation(s)
- Xitao Yu
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Xinyu Zhang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Xiaoqing Hu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Xinning Zhao
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Dianxiang Ren
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Xiaokai Li
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Pan Ma
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Chuncheng Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Yong Wu
- Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
| | - Sizuo Luo
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
| | - Dajun Ding
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China
- Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, China
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5
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García-Alfonso E, Barranco M, Bonhommeau DA, Halberstadt N, Pi M, Calvo F. Clustering, collision, and relaxation dynamics in pure and doped helium nanoclusters: Density- vs particle-based approaches. J Chem Phys 2022; 157:014106. [DOI: 10.1063/5.0091942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The clustering, collision, and relaxation dynamics of pristine and doped helium nanodroplets is theoretically investigated in cases of pickup and clustering of heliophilic argon, collision of heliophobic cesium atoms, and coalescence of two droplets brought into contact by their mutual long-range van der Waals interaction. Three approaches are used and compared with each other. The He time-dependent density functional theory method considers the droplet as a continuous medium and accounts for its superfluid character. The ring-polymer molecular dynamics method uses a path-integral description of nuclear motion and incorporates zero-point delocalization while bosonic exchange effects are ignored. Finally, the zero-point averaged dynamics approach is a mixed quantum–classical method in which quantum delocalization is described by attaching a frozen wavefunction to each He atom, equivalent to classical dynamics with effective interaction potentials. All three methods predict that the growth of argon clusters is significantly hindered by the helium host droplet due to the impeding shell structure around the dopants and kinematic effects freezing the growing cluster in metastable configurations. The effects of superfluidity are qualitatively manifested by different collision dynamics of the heliophilic atom at high velocities, as well as quadrupole oscillations that are not seen with particle-based methods, for droplets experiencing a collision with cesium atoms or merging with each other.
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Affiliation(s)
- Ernesto García-Alfonso
- Laboratoire Collisions, Agrégats, Réactivité (LCAR), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Manuel Barranco
- Laboratoire Collisions, Agrégats, Réactivité (LCAR), Université de Toulouse, CNRS, 31062 Toulouse, France
- Department FQA, Facultat de Física, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
| | - David A. Bonhommeau
- Université de Reims Champagne Ardenne, CNRS, GSMA UMR 7331, 51100 Reims, France
| | - Nadine Halberstadt
- Laboratoire Collisions, Agrégats, Réactivité (LCAR), Université de Toulouse, CNRS, 31062 Toulouse, France
| | - Martí Pi
- Department FQA, Facultat de Física, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
| | - Florent Calvo
- Université Grenoble Alpes, CNRS, LIPHY, F38000 Grenoble, France
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6
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Ellis AM, Davies JA, Yurtsever E, Calvo F. Dimerization dynamics of carboxylic acids in helium nanodroplets. J Chem Phys 2022; 156:174304. [PMID: 35525638 DOI: 10.1063/5.0087957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The dimerization of molecules in helium nanodroplets is known to preferentially yield structures of higher energy than the global energy minimum structure for a number of quite different monomers. Here, we explore dimerization in this environment using an atomistic model within statistically converged molecular dynamics (MD) trajectories, treating the solvent implicitly through the use of a thermostat, or more explicitly by embedding one monomer in a He100 cluster. The focus is on the two simplest carboxylic acids, formic and acetic, both of which have been studied experimentally. While the global minimum structure, which comprises two CO⋯HO hydrogen bonds, is predicted to be the most abundant dimer in the absence of the helium solvent, this is no longer the case once helium atoms are included. The simulations confirm the importance of kinetic trapping effects and also shed light on the occurrence of specific dynamical effects, leading to the occasional formation of high-energy structures away from minima, such as saddle configurations. Theoretically predicted infrared spectra, based on the MD statistics, are in good agreement with the experimental spectra.
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Affiliation(s)
- Andrew M Ellis
- School of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | - Julia A Davies
- School of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | - Ersin Yurtsever
- Department of Chemistry, Koç University, Rumelifeneri Yolu, Sariyer, 34450 Istanbul, Turkey
| | - Florent Calvo
- Université Grenoble Alpes, CNRS, LiPhy, F38000 Grenoble, France
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7
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Schouder CA, Chatterley AS, Pickering JD, Stapelfeldt H. Laser-Induced Coulomb Explosion Imaging of Aligned Molecules and Molecular Dimers. Annu Rev Phys Chem 2022; 73:323-347. [PMID: 35081323 DOI: 10.1146/annurev-physchem-090419-053627] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We discuss how Coulomb explosion imaging (CEI), triggered by intense femtosecond laser pulses and combined with laser-induced alignment and covariance analysis of the angular distributions of the recoiling fragment ions, provides new opportunities for imaging the structures of molecules and molecular complexes. First, focusing on gas phase molecules, we show how the periodic torsional motion of halogenated biphenyl molecules can be measured in real time by timed CEI, and how CEI of one-dimensionally aligned difluoroiodobenzene molecules can uniquely identify four structural isomers. Next, focusing on molecular complexes formed inside He nanodroplets, we show that the conformations of noncovalently bound dimers or trimers, aligned in one or three dimensions, can be determined by CEI. Results presented for homodimers of CS2, OCS, and bromobenzene pave the way for femtosecond time-resolved structure imaging of molecules undergoing bimolecular interactions and ultimately chemical reactions. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 73 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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8
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Zhang J, Trejo M, Bradford SD, Lei L, Kong W. Electron Diffraction of Ionic Argon Nanoclusters Embedded in Superfluid Helium Droplets. J Phys Chem Lett 2021; 12:9644-9650. [PMID: 34586826 PMCID: PMC8550877 DOI: 10.1021/acs.jpclett.1c02712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report electron diffraction of cationic argon nanoclusters embedded in superfluid helium droplets. Superfluid helium droplets are first doped with neutral argon atoms to form nanoclusters, and then the doped droplets are ionized by electrons. The much lower ionization energy of argon ensures that the positive charge resides on the Ar nanocluster. Using different stagnation temperatures and therefore droplets with different sizes, we have been able to preferentially form a small ionic cluster containing 2-4 Ar atoms and a larger cluster containing 7-11 atoms. The fitting results of the diffraction profiles agree with structures reported from theoretical calculations, containing a cationic trimer core with the remaining atoms largely neutral. This work testifies to the feasibility of performing electron diffraction from ionic species embedded in superfluid helium droplets, dispelling the concern over the particle density in the diffraction region. However, the large number of neutral helium atoms surrounding the cationic nanoclusters poses a challenge for the detection of the helium solvation layer, and the detection of which awaits further technological improvements.
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Affiliation(s)
| | | | | | | | - Wei Kong
- Corresponding author, , 541-737-6714
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9
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Vallance C, Heathcote D, Lee JWL. Covariance-Map Imaging: A Powerful Tool for Chemical Dynamics Studies. J Phys Chem A 2021; 125:1117-1133. [DOI: 10.1021/acs.jpca.0c10038] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Claire Vallance
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - David Heathcote
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
| | - Jason W. L. Lee
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford OX1 3TA, U.K
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10
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Zhou W, Ge L, Cooper GA, Crane SW, Evans MH, Ashfold MNR, Vallance C. Coulomb explosion imaging for gas-phase molecular structure determination: An ab initio trajectory simulation study. J Chem Phys 2020; 153:184201. [PMID: 33187401 DOI: 10.1063/5.0024833] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Coulomb explosion velocity-map imaging is a new and potentially universal probe for gas-phase chemical dynamics studies, capable of yielding direct information on (time-evolving) molecular structure. The approach relies on a detailed understanding of the mapping between the initial atomic positions within the molecular structure of interest and the final velocities of the fragments formed via Coulomb explosion. Comprehensive on-the-fly ab initio trajectory studies of the Coulomb explosion dynamics are presented for two prototypical small molecules, formyl chloride and cis-1,2-dichloroethene, in order to explore conditions under which reliable structural information can be extracted from fragment velocity-map images. It is shown that for low parent ion charge states, the mapping from initial atomic positions to final fragment velocities is complex and very sensitive to the parent ion charge state as well as many other experimental and simulation parameters. For high-charge states, however, the mapping is much more straightforward and dominated by Coulombic interactions (moderated, if appropriate, by the requirements of overall spin conservation). This study proposes minimum requirements for the high-charge regime, highlights the need to work in this regime in order to obtain robust structural information from fragment velocity-map images, and suggests how quantitative structural information may be extracted from experimental data.
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Affiliation(s)
- Weiwei Zhou
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd., Oxford OX1 3TA, United Kingdom
| | - Lingfeng Ge
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Graham A Cooper
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Stuart W Crane
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Michael H Evans
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Michael N R Ashfold
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
| | - Claire Vallance
- Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Rd., Oxford OX1 3TA, United Kingdom
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11
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Zhang J, Bradford SD, Kong W, Zhang C, Xue L. Electron diffraction of CS 2 nanoclusters embedded in superfluid helium droplets. J Chem Phys 2020; 152:224306. [PMID: 32534524 PMCID: PMC7292678 DOI: 10.1063/5.0011340] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 05/25/2020] [Indexed: 11/14/2022] Open
Abstract
We report experimental results from electron diffraction of CS2 nanoclusters embedded in superfluid helium droplets. From detailed measurements of the sizes of doped droplets, we can model the doping statistics under different experimental conditions, thereby obtaining the range of cluster sizes of CS2. Using a least squares fitting procedure, we can then determine the structures and contributions of dimers, trimers, and tetramers embedded in small droplets. While dimers prefer a stable gas phase structure, trimers and tetramers seem to forgo the highly symmetric gas phase structures and prefer compact cuts from the crystalline structure of CS2. In larger droplets containing more than 12 CS2 monomers, the diffraction profile is consistent with a three-dimensional nanostructure of bulk CS2. This work demonstrates the feasibility of electron diffraction for in situ monitoring of nanocluster formation in superfluid helium droplets.
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Affiliation(s)
- Jie Zhang
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - Stephen D. Bradford
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - Wei Kong
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA
| | - Chengzhu Zhang
- Department of Statistics, Oregon State University, Corvallis, Oregon 97331, USA
| | - Lan Xue
- Department of Statistics, Oregon State University, Corvallis, Oregon 97331, USA
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12
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Chatterley AS, Baatrup MO, Schouder CA, Stapelfeldt H. Laser-induced alignment dynamics of gas phase CS 2 dimers. Phys Chem Chem Phys 2020; 22:3245-3253. [PMID: 31995073 DOI: 10.1039/c9cp06260b] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rotational dynamics of gas phase carbon disulfide (CS2) dimers were induced by a moderately intense, circularly polarized alignment laser pulse and measured as a function of time by Coulomb explosion imaging with an intense fs probe pulse. For the alignment pulse, two different temporal intensity profiles were used: a truncated pulse with a 150 ps turn-on and a 8 ps turn-off, or a 'kick' pulse with a duration of 1.3 ps. For both types of pulse, rich rotational dynamics with characteristic full and fractional revivals were recorded, showing that the intermolecular carbon-carbon axis periodically aligns along the propagation direction of the laser pulses. The truncated pulse gave the strongest alignment, which we rationalize as being due to a flat relative phase between the components in the rotational wave packet generated. Fourier analysis of the alignment dynamics gave well-spaced peaks which were fit to determine the rotational constant, B, and the centrifugal constant, DJ, for the ground state of the dimer. Our results agree with values from high-resolution IR spectroscopy. Numerical simulations of the alignment accurately reproduced the experimental dynamics when the truncated pulse or a low intensity kick pulse was used, but failed to reproduce the dynamics induced by a high intensity kick pulse. We posit that the discrepancy is due to excitation of the intermolecular torsional motion by the kick pulse.
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Affiliation(s)
| | - Mia O Baatrup
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - Constant A Schouder
- Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
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13
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Lei L, Yao Y, Zhang J, Tronrud D, Kong W, Zhang C, Xue L, Dontot L, Rapacioli M. Electron Diffraction of Pyrene Nanoclusters Embedded in Superfluid Helium Droplets. J Phys Chem Lett 2020; 11:724-729. [PMID: 31884792 PMCID: PMC7104692 DOI: 10.1021/acs.jpclett.9b03603] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report electron diffraction of pyrene nanoclusters embedded in superfluid helium droplets. Using a least-squares fitting procedure, we have been able to separate the contribution of helium from those of the pyrene nanoclusters and determine the most likely structures for dimers and trimers. We confirm that pyrene dimers form a parallel double-layer structure with an interlayer distance of 3.5 Å and suggest that pyrene trimers form a sandwich structure but that the molecular planes are not completely parallel. The relative contributions of the dimers and trimers are ∼6:1. This work is an extension of our effort of solving structures of biological molecules using serial single-molecule electron diffraction imaging. The success of electron diffraction from an all-light-atom sample embedded in helium droplets offers reassuring evidence of the feasibility of this approach.
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Affiliation(s)
- Lei Lei
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Yuzhong Yao
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Jie Zhang
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Dale Tronrud
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Wei Kong
- Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States
| | - Chengzhu Zhang
- Department of Statistics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Lan Xue
- Department of Statistics, Oregon State University, Corvallis, Oregon 97331, United States
| | - Léo Dontot
- Laboratoire de Chimie et Physique Quantiques, LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques, LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
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14
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Davies JA, Besley NA, Yang S, Ellis AM. Infrared spectroscopy of a small ion solvated by helium: OH stretching region of HeN−HOCO+. J Chem Phys 2019; 151:194307. [DOI: 10.1063/1.5124137] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Julia A. Davies
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Shengfu Yang
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | - Andrew M. Ellis
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
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15
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Schouder C, Chatterley AS, Calvo F, Christiansen L, Stapelfeldt H. Structure determination of the tetracene dimer in helium nanodroplets using femtosecond strong-field ionization. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:044301. [PMID: 31463336 PMCID: PMC6711753 DOI: 10.1063/1.5118005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 08/09/2019] [Indexed: 05/29/2023]
Abstract
Dimers of tetracene molecules are formed inside helium nanodroplets and identified through covariance analysis of the emission directions of kinetic tetracene cations stemming from femtosecond laser-induced Coulomb explosion. Next, the dimers are aligned in either one or three dimensions under field-free conditions by a nonresonant, moderately intense laser pulse. The experimental angular covariance maps of the tetracene ions are compared to calculated covariance maps for seven different dimer conformations and found to be consistent with four of these. Additional measurements of the alignment-dependent strong-field ionization yield of the dimer narrow the possible conformations down to either a slipped-parallel or parallel-slightly rotated structure. According to our quantum chemistry calculations, these are the two most stable gas-phase conformations of the dimer and one of them is favorable for singlet fission.
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Affiliation(s)
- Constant Schouder
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark
| | - Adam S Chatterley
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Florent Calvo
- Université Grenoble Alpes CNRS, LIPHY, F-38000 Grenoble, France
| | - Lars Christiansen
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
| | - Henrik Stapelfeldt
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark
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Long-lasting field-free alignment of large molecules inside helium nanodroplets. Nat Commun 2019; 10:133. [PMID: 30635554 PMCID: PMC6329814 DOI: 10.1038/s41467-018-07995-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 12/05/2018] [Indexed: 11/09/2022] Open
Abstract
Molecules with their axes sharply confined in space, available through laser-induced alignment methods, are essential for many current experiments, including ultrafast molecular imaging. For these applications the aligning laser field should ideally be turned-off, to avoid undesired perturbations, and the strong alignment should last long enough that reactions and dynamics can be mapped out. Presently, this is only possible for small, linear molecules and for times less than 1 picosecond. Here, we demonstrate strong, field-free alignment of large molecules inside helium nanodroplets, lasting >10 picoseconds. One-dimensional or three-dimensional alignment is created by a slowly switched-on laser pulse, made field-free through rapid pulse truncation, and retained thanks to the impeding effect of the helium environment on molecular rotation. The opportunities field-free aligned molecules open are illustrated by measuring the alignment-dependent strong-field ionization yield of dibromothiophene oligomers. Our technique will enable molecular frame experiments, including ultrafast excited state dynamics, on a variety of large molecules and complexes.
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Davies JA, Hanson-Heine MWD, Besley NA, Shirley A, Trowers J, Yang S, Ellis AM. Dimers of acetic acid in helium nanodroplets. Phys Chem Chem Phys 2019; 21:13950-13958. [DOI: 10.1039/c8cp05934a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two metastable dimers are created inside superfluid helium and studied using infrared spectroscopy to provide insight into condensed phase structures.
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Affiliation(s)
| | | | | | - Andrew Shirley
- Department of Chemistry
- University of Leicester
- Leicester
- UK
| | - James Trowers
- Department of Chemistry
- University of Leicester
- Leicester
- UK
| | - Shengfu Yang
- Department of Chemistry
- University of Leicester
- Leicester
- UK
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