1
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Coppola F, Cimino P, Petrone A, Rega N. Evidence of Excited-State Vibrational Mode Governing the Photorelaxation of a Charge-Transfer Complex. J Phys Chem A 2024; 128:1620-1633. [PMID: 38381887 DOI: 10.1021/acs.jpca.3c08366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
Modern, nonlinear, time-resolved spectroscopic techniques have opened new doors for investigating the intriguing but complex world of photoinduced ultrafast out-of-equilibrium phenomena and charge dynamics. The interaction between light and matter introduces an additional dimension, where the complex interplay between electronic and vibrational dynamics needs the most advanced theoretical-computational protocols to be fully understood on the molecular scale. In this study, we showcase the capabilities of ab initio molecular dynamics simulation integrated with a multiresolution wavelet protocol to carefully investigate the excited-state relaxation dynamics in a noncovalent complex involving tetramethylbenzene (TMB) and tetracyanoquinodimethane (TCNQ) undergoing charge transfer (CT) upon photoexcitation. Our protocol provides an accurate description that facilitates a direct comparison between transient vibrational analysis and time-resolved spectroscopic signals. This molecular level perspective enhances our understanding of photorelaxation processes confined in the adiabatic regime and offers an improved interpretation of vibrational spectra. Furthermore, it enables the quantification of anharmonic vibrational couplings between high- and low-frequency modes, specifically the TCNQ "rocking" and "bending" modes. Additionally, it identifies the primary vibrational mode that governs the adiabaticity between the ground state and the CT state. This comprehensive understanding of photorelaxation processes holds significant importance in the rational design and precise control of more efficient photovoltaic and sensor devices.
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Affiliation(s)
- Federico Coppola
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
| | - Paola Cimino
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario di M.S. Angelo, 80126 Napoli, Italy
| | - Alessio Petrone
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario di M.S. Angelo, 80126 Napoli, Italy
- Istituto Nazionale Di Fisica Nucleare, sezione di Napoli, Complesso Universitario di Monte S. Angelo ed. 6, 80126 Napoli, Italia
| | - Nadia Rega
- Scuola Superiore Meridionale, Largo San Marcellino 10, I-80138 Napoli, Italy
- Department of Chemical Sciences, University of Napoli Federico II, Complesso Universitario di M.S. Angelo, 80126 Napoli, Italy
- Istituto Nazionale Di Fisica Nucleare, sezione di Napoli, Complesso Universitario di Monte S. Angelo ed. 6, 80126 Napoli, Italia
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2
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González-Vázquez J, García GA, Chicharro DV, Bañares L, Poullain SM. Evidencing an elusive conical intersection in the dissociative photoionization of methyl iodide. Chem Sci 2024; 15:3203-3213. [PMID: 38425510 PMCID: PMC10901492 DOI: 10.1039/d3sc04065h] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 12/23/2023] [Indexed: 03/02/2024] Open
Abstract
The valence-shell dissociative photoionization of methyl iodide (CH3I) is studied using double imaging photoelectron photoion coincidence (i2 PEPICO) spectroscopy in combination with highly-tunable synchrotron radiation from synchrotron SOLEIL. The experimental results are complemented by new high-level ab initio calculations of the potential energy curves of the relevant electronic states of the methyl iodide cation (CH3I+). An elusive conical intersection is found to mediate internal conversion from the initially populated first excited state, CH3I+(Ã2A1), into the ground cationic state, leading to the formation of methyl ions (CH3+). The reported threshold photoelectron spectrum for CH3+ reveals that the ν5 scissors vibrational mode promotes the access to this conical intersection and hence, the transfer of population. An intramolecular charge transfer takes place simultaneously, prior to dissociation. Upon photoionization into the second excited cationic state, CH3I+(B̃2E), a predissociative mechanism is shown to lead to the formation of atomic I+.
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Affiliation(s)
- Jesús González-Vázquez
- Departamento de Química, Facultad de Ciencias, Universidad Autónoma de Madrid Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid 28049 Madrid Spain
| | - Gustavo A García
- Synchrotron SOLEIL L'Orme des Merisiers, St. Aubin, BP 48 91192 Gif-sur-Yvette France
| | - David V Chicharro
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
| | - Luis Bañares
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanoscience) Cantoblanco 28049 Madrid Spain
| | - Sonia Marggi Poullain
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
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3
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Pratt ST, Jacovella U, Gans B, Bozek JD, Holland DMP. Resonant Auger decay of dissociating CH3I near the I 4d threshold. J Chem Phys 2024; 160:074304. [PMID: 38375906 DOI: 10.1063/5.0190794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/22/2024] [Indexed: 02/21/2024] Open
Abstract
Resonant Auger processes provide a unique perspective on electronic interactions and excited vibrational and electronic states of molecular ions. Here, new data are presented on the resonant Auger decay of excited CH3I in the region just below the I 4d-1 ionization threshold. The resonances include the Rydberg series converging to the five spin-orbit and ligand-field split CH3I (I 4d-1) thresholds, as well as resonances corresponding to excitation from the I 4d5/2,3/2 orbitals into the σ* lowest unoccupied molecular orbital. This study focuses on participator decay that populates the lowest lying states of CH3I+, in particular, the X̃2E3/2 and 2E1/2 states, and on spectator decay that populates the lowest-lying (CH3I2+)σ* states of CH3I+. The CH3I (I 4d-1)σ* resonances are broad, and dissociation to CH3 + I competes with the autoionization of the core-excited states. Auger decay as the molecule dissociates produces a photoelectron spectrum with a long progression (up to v3+ ∼ 25) in the C-I stretching mode of the X̃2E3/2 and 2E1/2 states, providing insights into the shape of the dissociative core-excited surface. The observed spectator decay processes indicate that CH3I+ is formed on the repulsive wall of the lower-lying (CH3I2+)σ* potentials, and the photon-energy dependence of the processes provides insights into the relative slopes of the (4d-1)σ* and (CH3I2+)σ* potential surfaces. Data are also presented for the spectator decay of higher lying CH3I (I 4d-1)nl Rydberg resonances. Photoelectron angular distributions for the resonant Auger processes provide additional information that helps distinguish these processes from the direct ionization signal.
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Affiliation(s)
- Stephen T Pratt
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Ugo Jacovella
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, F-91405 Orsay, France
| | - Bérenger Gans
- Institut des Sciences Moléculaires d'Orsay, CNRS, Université Paris-Saclay, F-91405 Orsay, France
| | - John D Bozek
- Synchrotron SOLEIL, L'Orme des Merisiers, Départmentale 128, 91190 Saint-Aubin, France
| | - David M P Holland
- STFC, Daresbury Laboratory, Daresbury, Warrington, Cheshire WA4 4AD, United Kingdom
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4
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Gong X, Zhang W, Lu P, Ni H, Wu J. Probing and Steering Attosecond Electron Motion Using Tailored Ultrafast Laser Fields. J Phys Chem A 2024; 128:401-412. [PMID: 38181198 DOI: 10.1021/acs.jpca.3c06613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2024]
Abstract
An ultrafast intense laser field is one of the most important tools to observe and manipulate electronic and nuclear dynamics with subcycle precision in highly nonlinear light-matter interactions, which provides access to attosecond chemistry and physics. In this review, we briefly summarize the protocol of attosecond chronoscopy and its application in probing the attosecond photoemission dynamics from atoms and molecules. We also review the control schemes of attosecond electron motion in atoms and molecules as well as molecular bond formation and cleavage with the assistance of tailored femtosecond laser fields.
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Affiliation(s)
- Xiaochun Gong
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Wenbin Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Peifen Lu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Hongcheng Ni
- 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
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5
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Bäuml L, Rott F, Schnappinger T, de Vivie-Riedle R. Following the Nonadiabatic Ultrafast Dynamics of Uracil via Simulated X-ray Absorption Spectra. J Phys Chem A 2023; 127:9787-9796. [PMID: 37955656 DOI: 10.1021/acs.jpca.3c06509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
The nucleobase uracil exhibits high photostability due to ultrafast relaxation processes mediated by conical intersections (CoIns), where the interplay between nuclear and electron dynamics becomes crucial. In our previous study, we observed seemingly long-lived traces of electronic coherence for the relaxation process through the S2/S1 CoIn by applying our ansatz for coupled nuclear and electron dynamics in molecules (NEMol). In this work, we theoretically investigate how time-dependent transient X-ray absorption spectroscopy can be used to observe this ultrafast dynamics. Therefore, we calculated X-ray absorption spectra (XAS) for the oxygen K-edge, using a multireference protocol in combination with NEMol dynamics. Thus, we have access to both the transient XAS based on the nuclear wavepacket dynamics and the modulation of the signals caused by the electronic coherence induced by the excitation process and the presence of a CoIn seam. In both cases, we were able to qualitatively predict its influence on the resulting XAS.
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Affiliation(s)
- Lena Bäuml
- Department of Chemistry, LMU Munich, Munich 81377, Germany
| | - Florian Rott
- Department of Chemistry, LMU Munich, Munich 81377, Germany
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6
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Kaczun T, Dempwolff AL, Huang X, Gelin MF, Domcke W, Dreuw A. Tuning UV Pump X-ray Probe Spectroscopy on the Nitrogen K Edge Reveals the Radiationless Relaxation of Pyrazine: Ab Initio Simulations Using the Quasiclassical Doorway-Window Approximation. J Phys Chem Lett 2023:5648-5656. [PMID: 37310800 DOI: 10.1021/acs.jpclett.3c01018] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Transient absorption UV pump X-ray probe spectroscopy has been established as a versatile technique for the exploration of ultrafast photoinduced dynamics in valence-excited states. In this work, an ab initio theoretical framework for the simulation of time-resolved UV pump X-ray probe spectra is presented. The method is based on the description of the radiation-matter interaction in the classical doorway-window approximation and a surface-hopping algorithm for the nonadiabatic nuclear excited-state dynamics. Using the second-order algebraic-diagrammatic construction scheme for excited states, UV pump X-ray probe signals were simulated for the carbon and nitrogen K edges of pyrazine, assuming a duration of 5 fs of the UV pump and X-ray probe pulses. It is predicted that spectra measured at the nitrogen K edge carry much richer information about the ultrafast nonadiabatic dynamics in the valence-excited states of pyrazine than those measured at the carbon K edge.
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Affiliation(s)
- Tobias Kaczun
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg D-69120, Germany
| | - Adrian L Dempwolff
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg D-69120, Germany
| | - Xiang Huang
- Department of Chemistry, Technical University of Munich, Garching D-85747, Germany
| | - Maxim F Gelin
- School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China
| | - Wolfgang Domcke
- Department of Chemistry, Technical University of Munich, Garching D-85747, Germany
| | - Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg D-69120, Germany
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7
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Cavaletto SM, Nam Y, Rouxel JR, Keefer D, Yong H, Mukamel S. Attosecond Monitoring of Nonadiabatic Molecular Dynamics by Transient X-ray Transmission Spectroscopy. J Chem Theory Comput 2023; 19:2327-2339. [PMID: 37015111 DOI: 10.1021/acs.jctc.3c00062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
Tracing the evolution of molecular coherences can provide a direct, unambiguous probe of nonadiabatic molecular processes, such as the passage through conical intersections of electronic states. Two techniques, attosecond transient absorption spectroscopy (ATAS) and Transient Redistribution of Ultrafast Electronic Coherences in Attosecond Raman Signals (TRUECARS), have been used or proposed for monitoring nonadiabatic molecular dynamics. Both techniques employ the transmission of a weak attosecond extreme-ultraviolet or X-ray probe to interrogate the molecule at controllable time delays with respect to an optical pump, thereby extracting dynamical information from transient spectral features. The connection between these techniques has not been firmly established yet. In this theoretical study, we provide a unified description of both transient transmission techniques, establishing their relationship as limits of the same pump-probe spectroscopy technique for different pulse parameter regimes. We demonstrate this by quantum dynamical simulations of thiophenol photodissociation and show how complementary coherence information can be revealed by the two techniques.
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Affiliation(s)
- Stefano M Cavaletto
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Yeonsig Nam
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Jérémy R Rouxel
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine, Irvine, California 92697, United States
- Université de Lyon, UJM-Saint-Étienne, CNRS, IOGS, Laboratoire Hubert Curien UMR 5516, Saint-Étienne 42023, France
| | - Daniel Keefer
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Haiwang Yong
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine, Irvine, California 92697, United States
| | - Shaul Mukamel
- Department of Chemistry and Department of Physics & Astronomy, University of California Irvine, Irvine, California 92697, United States
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8
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Yang W, Lötstedt E, Yamanouchi K. Theoretical transient absorption spectroscopy of trans-1,3‑butadiene in intense laser fields. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Gabalski I, Sere M, Acheson K, Allum F, Boutet S, Dixit G, Forbes R, Glownia JM, Goff N, Hegazy K, Howard AJ, Liang M, Minitti MP, Minns RS, Natan A, Peard N, Rasmus WO, Sension RJ, Ware MR, Weber PM, Werby N, Wolf TJA, Kirrander A, Bucksbaum PH. Transient vibration and product formation of photoexcited CS 2 measured by time-resolved x-ray scattering. J Chem Phys 2022; 157:164305. [PMID: 36319419 PMCID: PMC9625835 DOI: 10.1063/5.0113079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/03/2022] [Indexed: 11/14/2022] Open
Abstract
We have observed details of the internal motion and dissociation channels in photoexcited carbon disulfide (CS2) using time-resolved x-ray scattering (TRXS). Photoexcitation of gas-phase CS2 with a 200 nm laser pulse launches oscillatory bending and stretching motion, leading to dissociation of atomic sulfur in under a picosecond. During the first 300 fs following excitation, we observe significant changes in the vibrational frequency as well as some dissociation of the C-S bond, leading to atomic sulfur in the both 1D and 3P states. Beyond 1400 fs, the dissociation is consistent with primarily 3P atomic sulfur dissociation. This channel-resolved measurement of the dissociation time is based on our analysis of the time-windowed dissociation radial velocity distribution, which is measured using the temporal Fourier transform of the TRXS data aided by a Hough transform that extracts the slopes of linear features in an image. The relative strength of the two dissociation channels reflects both their branching ratio and differences in the spread of their dissociation times. Measuring the time-resolved dissociation radial velocity distribution aids the resolution of discrepancies between models for dissociation proposed by prior photoelectron spectroscopy work.
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Affiliation(s)
- Ian Gabalski
- Author to whom correspondence should be addressed:
| | | | - Kyle Acheson
- School of Chemistry, University of Edinburgh, Edinburgh EH8 9YL, United Kingdom
| | | | - Sébastien Boutet
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Gopal Dixit
- Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | | | - James M. Glownia
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Nathan Goff
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | | | | | - Mengning Liang
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Michael P. Minitti
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Russell S. Minns
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Adi Natan
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Nolan Peard
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - Weronika O. Rasmus
- School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom
| | - Roseanne J. Sension
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Matthew R. Ware
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
| | - Peter M. Weber
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | | | | | - Adam Kirrander
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QX Oxford, United Kingdom
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10
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Ashfold MNR, Kim SK. Non-Born-Oppenheimer effects in molecular photochemistry: an experimental perspective. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20200376. [PMID: 35341307 DOI: 10.1098/rsta.2020.0376] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/28/2021] [Indexed: 06/14/2023]
Abstract
Non-adiabatic couplings between Born-Oppenheimer (BO)-derived potential energy surfaces are now recognized as pivotal in describing the non-radiative decay of electronically excited molecules following photon absorption. This opinion piece illustrates how non-BO effects provide photostability to many biomolecules when exposed to ultraviolet radiation, yet in many other cases are key to facilitating 'reactive' outcomes like isomerization and bond fission. The examples are presented in order of decreasing molecular complexity, spanning studies of organic sunscreen molecules in solution, through two families of heteroatom containing aromatic molecules and culminating with studies of isolated gas phase H2O molecules that afford some of the most detailed insights yet available into the cascade of non-adiabatic couplings that enable the evolution from photoexcited molecule to eventual products. This article is part of the theme issue 'Chemistry without the Born-Oppenheimer approximation'.
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Affiliation(s)
| | - Sang Kyu Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
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11
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A localized view on molecular dissociation via electron-ion partial covariance. Commun Chem 2022; 5:42. [PMID: 36697752 PMCID: PMC9814695 DOI: 10.1038/s42004-022-00656-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/21/2022] [Indexed: 02/01/2023] Open
Abstract
Inner-shell photoelectron spectroscopy provides an element-specific probe of molecular structure, as core-electron binding energies are sensitive to the chemical environment. Short-wavelength femtosecond light sources, such as Free-Electron Lasers (FELs), even enable time-resolved site-specific investigations of molecular photochemistry. Here, we study the ultraviolet photodissociation of the prototypical chiral molecule 1-iodo-2-methylbutane, probed by extreme-ultraviolet (XUV) pulses from the Free-electron LASer in Hamburg (FLASH) through the ultrafast evolution of the iodine 4d binding energy. Methodologically, we employ electron-ion partial covariance imaging as a technique to isolate otherwise elusive features in a two-dimensional photoelectron spectrum arising from different photofragmentation pathways. The experimental and theoretical results for the time-resolved electron spectra of the 4d3/2 and 4d5/2 atomic and molecular levels that are disentangled by this method provide a key step towards studying structural and chemical changes from a specific spectator site.
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12
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Chang KF, Wang H, Poullain SM, González-Vázquez J, Bañares L, Prendergast D, Neumark DM, Leone SR. Conical intersection and coherent vibrational dynamics in alkyl iodides captured by attosecond transient absorption spectroscopy. J Chem Phys 2022; 156:114304. [DOI: 10.1063/5.0086775] [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 photodissociation dynamics of alkyl iodides along the C–I bond are captured by attosecond extreme-ultraviolet (XUV) transient absorption spectroscopy employing resonant ∼20 fs UV pump pulses. The methodology of previous experiments on CH3I [Chang et al., J. Chem. Phys. 154, 234301 (2021)] is extended to the investigation of a C–I bond-breaking reaction in the dissociative A-band of C2H5I, i-C3H7I, and t-C4H9I. Probing iodine 4 d core-to-valence transitions in the XUV enables one to map wave packet bifurcation at a conical intersection in the A-band as well as coherent vibrations in the ground state of the parent molecules. Analysis of spectroscopic bifurcation signatures yields conical intersection crossing times of 15 ± 4 fs for CH3I, 14 ± 5 fs for C2H5I, and 24 ± 4 fs for i-C3H7I and t-C4H9I, respectively. Observations of coherent vibrations, resulting from a projection of A-band structural dynamics onto the ground state by resonant impulsive stimulated Raman scattering, indirectly reveal multimode C–I stretch and CCI bend vibrations in the A-bands of C2H5I, i-C3H7I, and t-C4H9I.
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Affiliation(s)
- Kristina F. Chang
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Han Wang
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Sonia M. Poullain
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Jesús González-Vázquez
- Departamento de Química, Universidad Autónoma de Madrid, Madrid 28049, Spain
- Institute of Advanced Research on Chemistry, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Luis Bañares
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid 28040, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanoscience), Cantoblanco 28049, Madrid, Spain
| | - David Prendergast
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Physics, University of California, Berkeley, California 94720, USA
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