51
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Anstöter CS, Matsika S. Understanding the Interplay between the Nonvalence and Valence States of the Uracil Anion upon Monohydration. J Phys Chem A 2020; 124:9237-9243. [DOI: 10.1021/acs.jpca.0c07407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Cate S. Anstöter
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
| | - Spiridoula Matsika
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States
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52
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Yuan DF, Liu Y, Qian CH, Kocheril GS, Zhang YR, Rubenstein BM, Wang LS. Polarization of Valence Orbitals by the Intramolecular Electric Field from a Diffuse Dipole-Bound Electron. J Phys Chem Lett 2020; 11:7914-7919. [PMID: 32898418 DOI: 10.1021/acs.jpclett.0c02514] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The diffuse electron in a dipole-bound state is spatially well separated from the valence electrons and is known to have negligible effects on the dipole-bound state's molecular structure. Here, we show that a dipole-bound state is observed in deprotonated 4-(2-phenylethynyl)-phenoxide anions, 348 cm-1 below the anion's detachment threshold. The photodetachment of the dipole-bound electron is observed to accompany a simultaneous shakeup process in valence orbitals in this aromatic molecular anion. This shakeup process is due to configuration mixing as a result of valence orbital polarization by the intramolecular electric field of the dipole-bound electron. This observation suggests that dipole-bound anions can serve as a new platform to probe how oriented electric fields influence the valence electronic structure of polyatomic molecules.
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Affiliation(s)
- Dao-Fu Yuan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Yuan Liu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Chen-Hui Qian
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - G Stephen Kocheril
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Yue-Rou Zhang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Brenda M Rubenstein
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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53
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Patel AM, Henley A, Parkes MA, Assmann M, Worth GA, Anderson JC, Fielding HH. Shining light on the electronic structure and relaxation dynamics of the isolated oxyluciferin anion. Phys Chem Chem Phys 2020; 22:19022-19032. [PMID: 32808948 DOI: 10.1039/d0cp03276j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Firefly bioluminescence is exploited widely in imaging in the biochemical and biomedical sciences; however, our fundamental understanding of the electronic structure and relaxation processes of the oxyluciferin that emits the light is still rudimentary. Here, we employ photoelectron spectroscopy and quantum chemistry calculations to investigate the electronic structure and relaxation of a series of model oxyluciferin anions. We find that changing the deprotonation site has a dramatic influence on the relaxation pathway following photoexcitation of higher lying electronically excited states. The keto form of the oxyluciferin anion is found to undergo internal conversion to the fluorescent S1 state, whereas we find evidence to suggest that the enol and enolate forms undergo internal conversion to a dipole bound state, possibly via the fluorescent S1 state. Partially resolved vibrational structure points towards the involvement of out-of-plane torsional motions in internal conversion to the dipole bound state, emphasising the combined electronic and structural role that the microenvironment plays in controlling the electronic relaxation pathway in the enzyme.
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Affiliation(s)
- Anand M Patel
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK.
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54
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Kang DH, An S, Kim SK. Real-Time Autodetachment Dynamics of Vibrational Feshbach Resonances in a Dipole-Bound State. PHYSICAL REVIEW LETTERS 2020; 125:093001. [PMID: 32915603 DOI: 10.1103/physrevlett.125.093001] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 07/13/2020] [Accepted: 08/06/2020] [Indexed: 06/11/2023]
Abstract
Feshbach resonances corresponding to metastable vibrational states of the dipole-bound state (DBS) have been interrogated in real time for the first time. The state-specific autodetachment rates of the DBS of the phenoxide anion in the cryogenically cooled ion trap have been directly measured, giving τ∼33.5 ps for the lifetime of the most prominent 11^{'1} mode (519 cm^{-1}). Overall, the lifetime of the individual DBS state is strongly mode dependent to give τ∼5 ps for the 18^{'1} mode (632 cm^{-1}) and τ∼12 ps for the 11^{'2} mode (1036 cm^{-1}). The qualitative trend of the experiment could be successfully explained by the Fermi's golden rule. Autodetachment of the 11^{'1}18^{'1} combination mode is found to be much accelerated (τ≤1.4 ps) than expected, and its bifurcation dynamics into either the 11^{1}18^{0} or 11^{0}18^{1} state of the neutral core radical, according to the propensity rule of Δv=-1, could be distinctly differentiated through the photoelectron images to provide the unprecedented deep insights into the interaction between electronic and nuclear dynamics of the DBS, challenging the most sophisticated theoretical calculations.
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Affiliation(s)
- Do Hyung Kang
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Sejun An
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
| | - Sang Kyu Kim
- Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea
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55
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Yuan DF, Liu Y, Qian CH, Zhang YR, Rubenstein BM, Wang LS. Observation of a π-Type Dipole-Bound State in Molecular Anions. PHYSICAL REVIEW LETTERS 2020; 125:073003. [PMID: 32857546 DOI: 10.1103/physrevlett.125.073003] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/07/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
We report the observation of a π-type dipole-bound state (π-DBS) in cryogenically cooled deprotonated 9-anthrol molecular anions (9AT^{-}) by resonant two-photon photoelectron imaging. A DBS is observed 191 cm^{-1} (0.0237 eV) below the detachment threshold, and the existence of the π-DBS is revealed by a distinct (s+d)-wave photoelectron angular distribution. The π-DBS is stabilized by the large anisotropic in-plane polarizability of 9AT. The population of the dipole-forbidden π-DBS is proposed to be via a nonadiabatic coupling with the dipole-allowed σ-type DBS mediated by molecular rotations.
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Affiliation(s)
- Dao-Fu Yuan
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yuan Liu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Chen-Hui Qian
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yue-Rou Zhang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Brenda M Rubenstein
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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56
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Anstöter CS, Verlet JRR. Gas-Phase Synthesis and Characterization of the Methyl-2,2-dicyanoacetate Anion Using Photoelectron Imaging and Dipole-Bound State Autodetachment. J Phys Chem Lett 2020; 11:6456-6462. [PMID: 32687376 DOI: 10.1021/acs.jpclett.0c02036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The methyl-2,2-dicyanoacetate anion is synthesized in an electrospray ionization source through a gas-phase reaction involving tetracyanoethylene and methanol. Photoelectron imaging is used to determine the isomeric form of the product. The photoelectron spectra and angular distributions are consistent with only a single isomer. Additionally, mode-specific vibrational autodetachment is observed. This can be correlated with the emission from a photoexcited dipole-bound state by considering the IR spectrum of the neutral molecule, adding further confirmation of the isomeric form and providing a binding energy of the dipole-bound state. Our experiments show how conventional photoelectron imaging can be used to determine detailed information about gas-phase reaction products.
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Affiliation(s)
- Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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57
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Wang YT, Ning CG, Liu HT, Wang LS. High-Resolution Photoelectron Imaging and Photodetachment Spectroscopy of Cryogenically Cooled IO –. J Phys Chem A 2020; 124:5720-5726. [DOI: 10.1021/acs.jpca.0c04080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yong-Tian Wang
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chuan-Gang Ning
- Department of Physics, State Key Laboratory of Low-Dimensional Quantum Physics, Tsinghua University, Beijing 100084, P. R. China
| | - Hong-Tao Liu
- Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, United States
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58
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Qian CH, Zhu GZ, Zhang YR, Wang LS. Photodetachment spectroscopy and resonant photoelectron imaging of the 2-naphthoxide anion via dipole-bound excited states. J Chem Phys 2020; 152:214307. [DOI: 10.1063/5.0011234] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Chen-Hui Qian
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Guo-Zhu Zhu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yue-Rou Zhang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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59
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Dobulis MA, Thompson MC, Sommerfeld T, Jarrold CC. Temporary anion states of fluorine substituted benzenes probed by charge transfer in O 2 -·C 6H 6-xF x (x = 0-5) ion-molecule complexes. J Chem Phys 2020; 152:204309. [PMID: 32486698 DOI: 10.1063/5.0011321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The broadband photoelectron source realized by detaching O2 -·X (X = neutral unsaturated molecule) complexes offers a unique opportunity to probe temporary anion states of the unsaturated species. Detachment of the ion molecule complex typically accesses a dissociative portion of the neutral potential, creating a continuum electron source that can undergo scattering with X. We present the application of this new approach to electron-neutral scattering toward a study of the series of fluorinated benzenes via photoelectron spectroscopy of O2 -·C6H6-xFx (x = 0-6) measured with several photon energies. We compare these spectra to the reference O2 -·hexane spectrum and observe evidence of temporary anion states of C6H6-xFx for species with x = 0-5 in the form of enhanced signal intensity at electron kinetic energies coinciding with the energies of the temporary anions. Furthermore, we observe autodetachment features in the x = 3, 5 spectra. Results of calculations on the isolated symmetric isomer of C6H3F3 suggest that the molecule cannot support a weakly-bound non-valence state that could be associated with the observed autodetachment. However, C6HF5 - is predicted to support a valence bound state, which, if produced by charge transfer from O2 - with sufficient vibrational energy, may undergo autodetachment. Finally, the [O2·C6F6]- spectrum is unique insofar as the spectrum is substantially higher in binding energy and qualitatively different from the x = 0-5 spectra. This result suggests much stronger interactions and charge delocalization between O2 - and C6F6.
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Affiliation(s)
- Marissa A Dobulis
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA
| | - Michael C Thompson
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA
| | - Thomas Sommerfeld
- Department of Chemistry and Physics, Southeast Louisiana University, SLU 10878, Hammond, Louisiana 70402, USA
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA
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60
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Anstöter CS, Mensa-Bonsu G, Nag P, Ranković M, Kumar T P R, Boichenko AN, Bochenkova AV, Fedor J, Verlet JRR. Mode-Specific Vibrational Autodetachment Following Excitation of Electronic Resonances by Electrons and Photons. PHYSICAL REVIEW LETTERS 2020; 124:203401. [PMID: 32501066 DOI: 10.1103/physrevlett.124.203401] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/01/2020] [Indexed: 06/11/2023]
Abstract
Electronic resonances commonly decay via internal conversion to vibrationally hot anions and subsequent statistical electron emission. We observed vibrational structure in such an emission from the nitrobenzene anion, in both the 2D electron energy loss and 2D photoelectron spectroscopy of the neutral and anion, respectively. The emission peaks could be correlated with calculated nonadiabatic coupling elements for vibrational modes to the electronic continuum from a nonvalence dipole-bound state. This autodetachment mechanism via a dipole-bound state is likely to be a common feature in both electron and photoelectron spectroscopies.
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Affiliation(s)
- Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Golda Mensa-Bonsu
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Pamir Nag
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Miloš Ranković
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Ragesh Kumar T P
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Anton N Boichenko
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | | | - Juraj Fedor
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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61
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Kent PRC, Annaberdiyev A, Benali A, Bennett MC, Landinez Borda EJ, Doak P, Hao H, Jordan KD, Krogel JT, Kylänpää I, Lee J, Luo Y, Malone FD, Melton CA, Mitas L, Morales MA, Neuscamman E, Reboredo FA, Rubenstein B, Saritas K, Upadhyay S, Wang G, Zhang S, Zhao L. QMCPACK: Advances in the development, efficiency, and application of auxiliary field and real-space variational and diffusion quantum Monte Carlo. J Chem Phys 2020; 152:174105. [DOI: 10.1063/5.0004860] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- P. R. C. Kent
- Center for Nanophase Materials Sciences Division and Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Abdulgani Annaberdiyev
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA
| | - Anouar Benali
- Computational Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, USA
| | - M. Chandler Bennett
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Edgar Josué Landinez Borda
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Peter Doak
- Center for Nanophase Materials Sciences Division and Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Hongxia Hao
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Jaron T. Krogel
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Ilkka Kylänpää
- Computational Physics Laboratory, Tampere University, P.O. Box 692, 33014 Tampere, Finland
| | - Joonho Lee
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Ye Luo
- Computational Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, USA
| | - Fionn D. Malone
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Cody A. Melton
- Sandia National Laboratories, Albuquerque, New Mexico 87123, USA
| | - Lubos Mitas
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA
| | - Miguel A. Morales
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Eric Neuscamman
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Fernando A. Reboredo
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Brenda Rubenstein
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Kayahan Saritas
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Shiv Upadhyay
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Guangming Wang
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA
| | - Shuai Zhang
- Laboratory for Laser Energetics, University of Rochester, 250 E River Rd., Rochester, New York 14623, USA
| | - Luning Zhao
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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62
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Verlet JRR, Anstöter CS, Bull JN, Rogers JP. Role of Nonvalence States in the Ultrafast Dynamics of Isolated Anions. J Phys Chem A 2020; 124:3507-3519. [PMID: 32233436 PMCID: PMC7212518 DOI: 10.1021/acs.jpca.0c01260] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Nonvalence states
of neutral molecules (Rydberg states) play important
roles in nonadiabatic dynamics of excited states. In anions, such
nonadiabatic transitions between nonvalence and valence states have
been much less explored even though they are believed to play important
roles in electron capture and excited state dynamics of anions. The
aim of this Feature Article is to provide an overview of recent experimental
observations, based on time-resolved photoelectron imaging, of valence
to nonvalence and nonvalence to valence transitions in anions and
to demonstrate that such dynamics may be commonplace in the excited
state dynamics of molecular anions and cluster anions.
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Affiliation(s)
- Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, United Kingdom
| | - Joshua P Rogers
- Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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63
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Med J, Sršeň Š, Slavíček P, Domaracka A, Indrajith S, Rousseau P, Fárník M, Fedor J, Kočišek J. Vibrationally Mediated Stabilization of Electrons in Nonpolar Matter. J Phys Chem Lett 2020; 11:2482-2489. [PMID: 32154726 DOI: 10.1021/acs.jpclett.0c00278] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We explore solvation of electrons in nonpolar matter, here represented by butadiene clusters. Isolated butadiene supports only the existence of transient anions (resonances). Two-dimensional electron energy loss spectroscopy shows that the resonances lead to an efficient vibrational excitation of butadiene, which can result into the almost complete loss of energy of the interacting electron. Cluster-beam experiments show that molecular clusters of butadiene form stable anions, however only at sizes of more than 9 molecular units. We have calculated the distribution of electron affinities of clusters using classical and path integral molecular dynamics simulations. There is almost a continuous transition from the resonant to the bound anions with an increase in cluster size. The comparison of the classical and quantum dynamics reveals that the electron binding is strongly supported by molecular vibrations, brought about by nuclear zero-point motion and thermal agitation. We also inspected the structure of the solvated electron, finding it well localized.
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Affiliation(s)
- Jakub Med
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, 16628 Prague 6, Czech Republic
| | - Štěpán Sršeň
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, 16628 Prague 6, Czech Republic
| | - Petr Slavíček
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, 16628 Prague 6, Czech Republic
- J. Heyrovský Institute of Physical Chemistry v.v.i., The Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - A Domaracka
- Normandie Univ., ENSICAEN, UNICAEN, CEA, CNRS, CIMAP, 14000 Caen, France
| | - S Indrajith
- Normandie Univ., ENSICAEN, UNICAEN, CEA, CNRS, CIMAP, 14000 Caen, France
| | - P Rousseau
- Normandie Univ., ENSICAEN, UNICAEN, CEA, CNRS, CIMAP, 14000 Caen, France
| | - M Fárník
- J. Heyrovský Institute of Physical Chemistry v.v.i., The Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - J Fedor
- J. Heyrovský Institute of Physical Chemistry v.v.i., The Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
| | - J Kočišek
- J. Heyrovský Institute of Physical Chemistry v.v.i., The Czech Academy of Sciences, Dolejškova 3, 18223 Prague, Czech Republic
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64
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Bull JN, Anstöter CS, Verlet JRR. Fingerprinting the Excited-State Dynamics in Methyl Ester and Methyl Ether Anions of Deprotonated para-Coumaric Acid. J Phys Chem A 2020; 124:2140-2151. [PMID: 32105474 DOI: 10.1021/acs.jpca.9b11993] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Chromophores based on the para-hydroxycinnamate moiety are widespread in the natural world, including as the photoswitching unit in photoactive yellow protein and as a sunscreen in the leaves of plants. Here, photodetachment action spectroscopy combined with frequency- and angle-resolved photoelectron imaging is used to fingerprint the excited-state dynamics over the first three bright action-absorption bands in the methyl ester anions (pCEs-) of deprotonated para-coumaric acid at a temperature of ∼300 K. The excited states associated with the action-absorption bands are classified as resonances because they are situated in the detachment continuum and are open to autodetachment. The frequency-resolved photoelectron spectrum for pCEs- indicates that all photon energies over the S1(ππ*) band lead to similar vibrational autodetachment dynamics. The S2(nπ*) band is Herzberg-Teller active and has comparable brightness to the higher lying 21(ππ*) band. The frequency-resolved photoelectron spectrum over the S2(nπ*) band indicates more efficient internal conversion to the S1(ππ*) state for photon energies resonant with the Franck-Condon modes (∼80%) compared with the Herzberg-Teller modes (∼60%). The third action-absorption band, which corresponds to excitation of the 21(ππ*) state, shows complex and photon energy-dependent dynamics, with 20-40% of photoexcited population internally converting to the S1(ππ*) state. There is also evidence for a mode-specific competition between prompt autodetachment and internal conversion on the red edge of the 21(ππ*) band. There is no evidence for recovery of the ground electronic state and statistical electron ejection (thermionic emission) following photoexcitation over any of the three action-absorption bands. The photoelectron spectra for the deprotonated methyl ether derivative (pCEt-) at photon energies over the S1(ππ*) and S2(nπ*) bands indicate diametrically opposed dynamics compared with pCEs-, namely, intense thermionic emission due to efficient recovery of the ground electronic state.
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Affiliation(s)
- James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich NR4 7TJ, U.K
| | - Cate S Anstöter
- Department of Chemistry, Durham University, Durham DH1 3LE, U.K
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham DH1 3LE, U.K
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65
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Dobulis MA, Thompson MC, Patros KM, Sommerfeld T, Jarrold CC. Emerging Nonvalence Anion States of [Isoprene-H·]·H 2O Accessed via Detachment of OH -·Isoprene. J Phys Chem A 2020; 124:2279-2287. [PMID: 32091900 DOI: 10.1021/acs.jpca.0c01250] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The anion photoelectron imaging spectra of an ion with m/z 85, generated under ion source conditions that optimize •OH production in a coexpansion with isoprene, are presented and analyzed with supporting calculations. A spectroscopic feature observed at a vertical electron detachment energy of 2.45 eV, which dominates the photoelectron spectrum measured at 3.495 eV photon energy, is consistent with the OH-·isoprene ion-molecule complex, while additional signal observed at lower electron binding energy can be attributed to other constitutional isomers. However, spectra measured over a 2.2-2.6 eV photon energy range, i.e., from near threshold of the predominant OH-·isoprene detachment feature through the vertical detachment energy, exhibit sharp features with common electron kinetic energies, suggesting autodetachment from a temporary anion prepared by photoexcitation. The photon energy independence of the electron kinetic energy of these features along with the low dipole moment predicted for the neutral •OH·isoprene van der Waals complex, suggest a complex photon-driven process. We present calculations supporting a hypothesis that near-threshold production of the •OH···isoprene reactive complex results in hydrogen abstraction of the isoprene molecule. The newly formed activated complex anion supports a dipole bound state that temporarily traps the near zero-kinetic energy electron and then autodetaches, encoding the low-frequency modes of the dehydrogenated neutral isoprene radical in the electron kinetic energies.
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Affiliation(s)
- Marissa A Dobulis
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Michael C Thompson
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Kellyn M Patros
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Thomas Sommerfeld
- Department of Chemistry and Physics, Southeast Louisiana University, SLU 10878, Hammond, Louisiana 70402, United States
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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66
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Anusiewicz I, Skurski P, Simons J. Fate of Dipole-Bound Anion States when Hydrated. J Phys Chem A 2020; 124:2064-2076. [PMID: 32065750 DOI: 10.1021/acs.jpca.0c00360] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many strongly polar molecules can form an anion by attaching an electron to either an empty or half-filled valence-bound (VB) orbital or a so-called dipole-bound (DB) orbital. These two families of orbitals can be very different in their radial extent (the former are usually more compact, while the latter are quite diffuse) and in the degree to which they are affected by surrounding solvent molecules. In this study, the effects of hydration (representative of strong solvation) on the DB state of a model polar species are investigated with an eye toward determining whether this state is stabilized or even persists when a few to 100 water molecules surround the polar molecule. It is found that in the presence of up to ca. 10-12 water molecules, the excess electron can remain in a DB orbital. However, once there are enough water molecules to form a complete first hydration shell (or more), the excess electron migrates into an orbital localized on the outer surface of the water solvent cage. These findings have implications on the possible role of DB states as doorways to facilitating electron attachment and subsequent electron transfer to VB states. It is shown that even when the electron is bound to the surface of the surrounding solvent, the dipole potential of the solute molecule can influence where on the surface the electron binds. It is also illustrated that using continuum dielectric methods to describe the hydration of DB states is fraught with danger because much of the outermost electron density in such states penetrates outside the boundary of the cavity used in these methods.
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Affiliation(s)
- Iwona Anusiewicz
- Laboratory of Quantum Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Piotr Skurski
- Laboratory of Quantum Chemistry, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.,Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Jack Simons
- Henry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
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67
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Sommerfeld T, Davis MC. Excluded-volume descriptors for dipole-bound anions: Amine N-oxides as a test case. J Chem Phys 2020; 152:054102. [PMID: 32035463 DOI: 10.1063/1.5142624] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Dipole-bound anions can be theoretically characterized at three fundamentally different levels. The highest are ab initio calculations, which themselves range from fairly approximate, say, Koopmans's Theorem (KT) or second-order Møller-Plesset perturbation theory, to highly sophisticated, say, the electron affinity equation-of-motion couple-cluster with single, double, and perturbative triple substitutions, which rivals experiments in reliability. The next level down is represented by one-electron model Hamiltonians. Again, one-electron model Hamiltonians can be fairly approximate, especially if the molecular system is modeled by a simple point-dipole and point-polarizable site; however, very reliable models have been developed for specific systems, for example, water clusters. At the lowest level, one can qualitatively explain trends in classes of dipole-bound anions in terms of the dipole moment, μ, the polarizability, α, and the so-called excluded volume, Vx. This project aims at the qualitative level. While the dipole moment and the polarizability possess clear-cut definitions, the excluded volume must-similar to all molecular volumes-remain a rather vaguely defined term, and so far, we are unaware of any quantitative definition in the literature. Here, we introduce and investigate three descriptors for Vx. To this end, we first establish a dataset with consistent ab initio results for 25 amine N-oxides structures. Then, we demonstrate that the descriptors are indeed able to explain trends for sets of isomers and conformers and investigate to what extent the descriptors are able to predict electron binding energy of dipole-bound states using simple quantitative structure-property relationship-like models. It turns out that μ and Vx provide a reasonably accurate prediction of the electrostatic part of the electron bind energy (the KT value) and that the polarizability α provides an acceptable prediction of the electron correlation contribution.
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Affiliation(s)
- Thomas Sommerfeld
- Department of Chemistry and Physics, Southeastern Louisiana University, SLU 10878, Hammond, Louisiana 70402, USA
| | - Megan C Davis
- Department of Chemistry and Physics, Southeastern Louisiana University, SLU 10878, Hammond, Louisiana 70402, USA
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68
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Lehtola S. Curing basis set overcompleteness with pivoted Cholesky decompositions. J Chem Phys 2020; 151:241102. [PMID: 31893881 DOI: 10.1063/1.5139948] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The description of weakly bound electronic states is especially difficult with atomic orbital basis sets. The diffuse atomic basis functions that are necessary to describe the extended electronic state generate significant linear dependencies in the molecular basis set, which may make the electronic structure calculations ill-convergent. We propose a method where the overcomplete molecular basis set is pruned by a pivoted Cholesky decomposition of the overlap matrix, yielding an optimal low-rank approximation that is numerically stable, the pivot indices determining a reduced basis set that is complete enough to describe all the basis functions in the original overcomplete basis. The method can be implemented either by a simple modification to the usual canonical orthogonalization procedure, which hides the excess functions and yields fewer efficiency benefits, or by generating custom basis sets for all the atoms in the system, yielding significant cost reductions in electronic structure calculations. The pruned basis sets from the latter choice allow accurate calculations to be performed at a lower cost even at the self-consistent field level, as illustrated on a solvated (H2O)24 - anion. Our results indicate that the Cholesky procedure allows one to perform calculations with accuracies close to standard augmented basis sets with cost savings which increase with the size of the basis set, ranging from 9% fewer functions in single-ζ basis sets to 28% fewer functions in triple-ζ basis sets.
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Affiliation(s)
- Susi Lehtola
- Department of Chemistry, University of Helsinki, P.O. Box 55 (A. I. Virtasen aukio 1), FI-00014 Helsinki, Finland
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69
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Gulania S, Jagau TC, Sanov A, Krylov AI. The quest to uncover the nature of benzonitrile anion. Phys Chem Chem Phys 2020; 22:5002-5010. [DOI: 10.1039/c9cp06484b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Anionic states of benzonitrile are investigated by high-level electronic structure methods.
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Affiliation(s)
- Sahil Gulania
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
| | | | - Andrei Sanov
- Department of Chemistry and Biochemistry
- University of Arizona
- Tucson
- USA
| | - Anna I. Krylov
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
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70
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Bull JN, Anstöter CS, Verlet JRR. Ultrafast valence to non-valence excited state dynamics in a common anionic chromophore. Nat Commun 2019; 10:5820. [PMID: 31862884 PMCID: PMC6925192 DOI: 10.1038/s41467-019-13819-6] [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: 10/01/2019] [Accepted: 11/27/2019] [Indexed: 12/19/2022] Open
Abstract
Non-valence states in neutral molecules (Rydberg states) have well-established roles and importance in photochemistry, however, considerably less is known about the role of non-valence states in photo-induced processes in anions. Here, femtosecond time-resolved photoelectron imaging is used to show that photoexcitation of the S1(ππ*) state of the methyl ester of deprotonated para-coumaric acid – a model chromophore for photoactive yellow protein (PYP) – leads to a bifurcation of the excited state wavepacket. One part remains on the S1(ππ*) state forming a twisted intermediate, whilst a second part leads to the formation of a non-valence (dipole-bound) state. Both populations eventually decay independently by vibrational autodetachment. Valence-to-non-valence internal conversion has hitherto not been observed in the intramolecular photophysics of an isolated anion, raising questions into how common such processes might be, given that many anionic chromophores have bright valence states near the detachment threshold. Photoactive biomolecules rely on chromophores whose photochemistry depends on the environment. Here, the excited state dynamics of a model for the anionic biochromophore in photoactive yellow protein is investigated by time-resolved photoelectron spectroscopy showing involvement of a non-valence state, and lack of E-Z isomerisation in the gas phase.
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Affiliation(s)
- James N Bull
- School of Chemistry, Norwich Research Park, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Cate S Anstöter
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK
| | - Jan R R Verlet
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK.
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71
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Qian CH, Zhu GZ, Wang LS. Probing the Critical Dipole Moment To Support Excited Dipole-Bound States in Valence-Bound Anions. J Phys Chem Lett 2019; 10:6472-6477. [PMID: 31589447 DOI: 10.1021/acs.jpclett.9b02679] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report photodetachment spectroscopy and high-resolution photoelectron imaging of para-halogen substituted phenoxide anions, p-XC6H4O- (X = F, Cl, Br, I). The dipole moments of the p-XC6H4O neutral radicals increase from 2.56 to 3.19 D for X = F to I, providing a series of similar molecules to allow the examination of charge-dipole interactions by minimizing molecule-dependent effects. Excited DBSs ([XC6H4O]*-) are observed for the four anions with binding energies of 8, 11, 24, and 53 cm-1, respectively, for X = F to I, below their respective detachment thresholds. The binding energies exhibit a linear correlation with the dipole moments of the neutral radicals, extrapolating to a critical dipole moment of 2.5 D for zero binding energy. Because of the small binding energy of the excited DBS of [FC6H4O]*-, rotational autodetachment is observed to compete with vibrational autodetachment in the resonant photoelectron spectra, resulting in electrons with near zero kinetic energies.
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Affiliation(s)
- Chen-Hui Qian
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Guo-Zhu Zhu
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Lai-Sheng Wang
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
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72
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Zhu GZ, Wang LS. High-resolution photoelectron imaging and resonant photoelectron spectroscopy via noncovalently bound excited states of cryogenically cooled anions. Chem Sci 2019; 10:9409-9423. [PMID: 32055317 PMCID: PMC6984392 DOI: 10.1039/c9sc03861b] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 09/16/2019] [Indexed: 01/12/2023] Open
Abstract
Valence-bound anions with polar neutral cores (μ > ∼2.5 D) can support dipole-bound excited states below the detachment threshold. These dipole-bound states (DBSs) are highly diffuse and the weakly bound electron in the DBS can be readily autodetached via vibronic coupling. Excited DBSs can be observed in photodetachment spectroscopy using a tunable laser. Tuning the detachment laser to above-threshold vibrational resonances yields vibrationally enhanced resonant photoelectron spectra, which are highly non-Franck-Condon with much richer vibrational information. This perspective describes recent advances in the studies of excited DBSs of cryogenically cooled anions using high-resolution photoelectron imaging (PEI) and resonant photoelectron spectroscopy (rPES). The basic features of dipole-bound excited states and highly non-Franck-Condon resonant photoelectron spectra will be discussed. The power of rPES to yield rich vibrational information beyond conventional PES will be highlighted, especially for low-frequency and Franck-Condon-inactive vibrational modes, which are otherwise not accessible from non-resonant conventional PES. Mode-selectivity and intra-molecular rescattering have been observed during the vibrationally induced autodetachment. Conformer-specific rPES is possible due to the different dipole-bound excited states of molecular conformers with polar neutral cores. For molecules with μ ≪ 2.5 D or without dipole moments, but large quadrupole moments, excited quadrupole-bound states can exist, which can also be used to conduct rPES.
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Affiliation(s)
- Guo-Zhu Zhu
- Department of Chemistry , Brown University , Providence , RI 02912 , USA .
| | - Lai-Sheng Wang
- Department of Chemistry , Brown University , Providence , RI 02912 , USA .
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73
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Castellani ME, Anstöter CS, Verlet JRR. On the stability of a dipole-bound state in the presence of a molecule. Phys Chem Chem Phys 2019; 21:24286-24290. [PMID: 31663558 DOI: 10.1039/c9cp04942h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dipole-bound states (DBSs) are diffuse non-valence molecular orbitals of anions where the electron is bound by the permanent dipole moment of the neutral core. Here, an experimental study of the stability of such orbitals under the influence of a perturbing molecular alkyl chain is presented. Photodetachment action and photoelectron imaging spectroscopy of five para-substituted phenolate anions with progressively longer alkyl chains show that the DBS survives in all cases, suggesting that the perturbation of the orbital is not critical to the existence of the DBS.
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74
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Mensa-Bonsu G, Lietard A, Verlet JRR. Enhancement of electron accepting ability of para-benzoquinone by a single water molecule. Phys Chem Chem Phys 2019; 21:21689-21692. [PMID: 31552961 DOI: 10.1039/c9cp04559g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Electron acceptors built upon the para-benzoquinone (pBQ) electrophore are ubiquitous in nature. Here, we present a frequency-resolved photoelectron spectroscopic study of the cold pBQ radical anion, pBQ-, solvated by a single water molecule, as commonly encountered in nature. Our results show that the electron accepting ability is enhanced by the single water molecule and by elevated temperatures.
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75
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Kairalapova A, Jordan KD, Falcetta MF, Steiner DK, Sutter BL, Gowen JS. Prediction of a Non-Valence Temporary Anion State of (NaCl)2. J Phys Chem B 2019; 123:9198-9205. [DOI: 10.1021/acs.jpcb.9b07782] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Arailym Kairalapova
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Michael F. Falcetta
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
| | - Dalton K. Steiner
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
| | - Brittni L. Sutter
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
| | - Josiah S. Gowen
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
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76
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Structure and spectrum of the hydrated electron. A combined quantum chemical statistical mechanical simulation. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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77
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Zhu GZ, Cheung LF, Liu Y, Qian CH, Wang LS. Resonant Two-Photon Photoelectron Imaging and Intersystem Crossing from Excited Dipole-Bound States of Cold Anions. J Phys Chem Lett 2019; 10:4339-4344. [PMID: 31314535 DOI: 10.1021/acs.jpclett.9b01743] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the observation of a dipole-bound state (DBS) 659 cm-1 below the electron detachment threshold of cryogenically cooled deprotonated 4,4'-biphenol anion (bPh-) and 19 of its lowest vibrational levels. Resonant two-photon photoelectron imaging (R2P-PEI) via the vibrational levels of the DBS displays a sharp peak with a constant binding energy. This observation indicates vertical detachment from the vibrational levels of the DBS to the corresponding neutral levels with the conservation of the vibrational energy, suggesting that the highly diffuse electron in the DBS has little effect on the neutral core. The R2P-PEI spectra also exhibit two features at lower binding energies, which come from intersystem crossings from the DBS to two lower-lying valence-bound triplet excited states of bPh-. The current study discloses the first R2P-PEI spectra from vibrational excited states of a DBS and direct spectroscopic evidence of transitions from a DBS to valence-bound states of anions.
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Affiliation(s)
- Guo-Zhu Zhu
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Ling Fung Cheung
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Yuan Liu
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Chen-Hui Qian
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - Lai-Sheng Wang
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
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78
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Zhu G, Qian C, Wang L. Tautomer‐Specific Resonant Photoelectron Imaging of Deprotonated Cytosine Anions. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201903444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Guo‐Zhu Zhu
- Department of Chemistry Brown University Providence RI 02912 USA
| | - Chen‐Hui Qian
- Department of Chemistry Brown University Providence RI 02912 USA
| | - Lai‐Sheng Wang
- Department of Chemistry Brown University Providence RI 02912 USA
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79
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Zhu G, Qian C, Wang L. Tautomer‐Specific Resonant Photoelectron Imaging of Deprotonated Cytosine Anions. Angew Chem Int Ed Engl 2019; 58:7856-7860. [DOI: 10.1002/anie.201903444] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Guo‐Zhu Zhu
- Department of ChemistryBrown University Providence RI 02912 USA
| | - Chen‐Hui Qian
- Department of ChemistryBrown University Providence RI 02912 USA
| | - Lai‐Sheng Wang
- Department of ChemistryBrown University Providence RI 02912 USA
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80
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Ab initio investigation of cationic water cluster (H2O)+13 via particle swarm optimization algorithm. Theor Chem Acc 2019. [DOI: 10.1007/s00214-019-2464-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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81
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Sun H, Zheng Q, Lu W, Zhao J. Ultrafast dynamics of solvated electrons at anatase TiO 2/H 2O interface. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:114004. [PMID: 30625440 DOI: 10.1088/1361-648x/aafcf6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Solvated electrons are known to be the lowest energy charge transfer pathways at oxide/aqueous interface and the understanding of the electron transfer dynamics at the interface is fundamental for photochemical and photocatalytic processes. Taking anatase TiO2/H2O interface as a prototypical system, we perform time-dependent ab initio nonadiabatic molecular dynamics calculations to study the charge transfer dynamics of solvated electrons. For the static electronic properties, we find that the dangling H atoms can stabilize solvated electrons. A solvated electron band can be formed with one monolayer H2O adsorption. The energies of the solvated electron band minimum (SEBM) decrease when H2O adsorbs dissociatively. Moreover, the surface oxygen vacancies are also helpful for stabilizing the solvated electron band. For the dynamics behaviour, we find that the ultrafast charge transfer from SEBM to anatase TiO2 (1 0 1) surface at 100 K is mainly contributed by nonadiabatic mechanism. Comparing with rutile TiO2 (1 1 0) surface, the lifetime of solvated electron on anatase TiO2 (1 0 1) surface is longer, suggesting a better photocatalytic properties. Our results provide essential insights into the understanding of the charge transfer dynamics and the possible photocatalytic mechanism at oxide/aqueous interface.
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Affiliation(s)
- Huijuan Sun
- College of Physics and State Key Laboratory of Bio-Fibers and Eco-Textiles, Qingdao University, Qingdao, Shandong 266071, People's Republic of China
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82
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Kairalapova A, Jordan KD, Maienshein DN, Fair MC, Falcetta MF. Prediction of a Nonvalence Temporary Anion Shape Resonance for a Model (H2O)4 System. J Phys Chem A 2019; 123:2719-2726. [DOI: 10.1021/acs.jpca.8b11881] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Arailym Kairalapova
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Daniel N. Maienshein
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
| | - Mark C. Fair
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
| | - Michael F. Falcetta
- Department of Chemistry, Grove City College, Grove City, Pennsylvania 16127, United States
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83
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Li Z, Ryszka M, Dawley MM, Carmichael I, Bravaya KB, Ptasińska S. Dipole-Supported Electronic Resonances Mediate Electron-Induced Amide Bond Cleavage. PHYSICAL REVIEW LETTERS 2019; 122:073002. [PMID: 30848645 DOI: 10.1103/physrevlett.122.073002] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 10/11/2018] [Indexed: 05/28/2023]
Abstract
Dissociative electron attachment (DEA) plays a key role in radiation damage of biomolecules under high-energy radiation conditions. The initial step in DEA is often rationalized in terms of resonant electron capture into one of the metastable valence states of a molecule followed by its fragmentation. Our combined theoretical and experimental investigations indicate that the manifold of states responsible for electron capture in the DEA process can be dominated by core-excited (shake-up) dipole-supported resonances. Specifically, we present the results of experimental and computational studies of the gas-phase DEA to three prototypical peptide molecules, formamide, N-methylformamide (NMF), and N,N-dimethyl-formamide (DMF). In contrast to the case of electron capture by positively charged peptides in which amide bond rupture is rare compared to N─C_{α} bond cleavage, fragmentation of the amide bond was observed in each of these three molecules. The ion yield curves for ions resulting from this amide bond cleavage, such as NH_{2}^{-} for formamide, NHCH_{3}^{-} for NMF, and N(CH_{3})_{2}^{-} for DMF, showed a double-peak structure in the region between 5 and 8 eV. The peaks are assigned to Feshbach resonances including core-excited dipole-supported resonances populated upon electron attachment based on high-level electronic structure calculations. Moreover, the lower energy peak is attributed to formation of the core-excited resonance that correlates with the triplet state of the neutral molecule. The latter process highlights the role of optically spin-forbidden transitions promoted by electron impact in the DEA process.
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Affiliation(s)
- Zhou Li
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Michal Ryszka
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - M Michele Dawley
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ian Carmichael
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
| | - Ksenia B Bravaya
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Sylwia Ptasińska
- Radiation Laboratory, University of Notre Dame, Notre Dame, Indiana 46556, USA
- Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA
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84
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Jerosimić SV, Milovanović MZ, Wester R, Gianturco FA. Dipole-bound states contribution to the formation of anionic carbonitriles in the ISM: Calculations using multireference methods for C3N−. ADVANCES IN QUANTUM CHEMISTRY 2019. [DOI: 10.1016/bs.aiq.2019.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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85
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Czekner J, Cheung LF, Kocheril GS, Wang LS. Probing the coupling of a dipole-bound electron with a molecular core. Chem Sci 2018; 10:1386-1391. [PMID: 30809355 PMCID: PMC6354839 DOI: 10.1039/c8sc04771e] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/15/2018] [Indexed: 11/21/2022] Open
Abstract
A dipolar molecule can weakly bind an electron in a diffuse orbital. However, the spin-orbit coupling between this weakly bound electron and the electrons in the molecular core is not known. Here we probe this coupling using the linear C2P- anion with the 3Σ+ ground state, which possesses dipole-bound excited states because neutral C2P (2Π) has a sufficiently large dipole moment. Photodetachment spectroscopy and resonant photoelectron spectroscopy are used to probe the nature of the dipole-bound states. Two dipole-bound excited states are observed with a binding energy of 37 cm-1, corresponding to the two spin-orbit states of neutral C2P (2Π1/2 and 2Π3/2). The current study demonstrates that the weakly bound electron in the dipole-bound excited states of C2P- is not spin-coupled to the electrons in the C2P core and can be considered as a quasi-free electron.
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Affiliation(s)
- Joseph Czekner
- Brown University , Department of Chemistry , 324 Brook Street , Providence , RI 02912 , USA .
| | - Ling Fung Cheung
- Brown University , Department of Chemistry , 324 Brook Street , Providence , RI 02912 , USA .
| | - G Stephen Kocheril
- Brown University , Department of Chemistry , 324 Brook Street , Providence , RI 02912 , USA .
| | - Lai-Sheng Wang
- Brown University , Department of Chemistry , 324 Brook Street , Providence , RI 02912 , USA .
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86
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Hao H, Shee J, Upadhyay S, Ataca C, Jordan KD, Rubenstein BM. Accurate Predictions of Electron Binding Energies of Dipole-Bound Anions via Quantum Monte Carlo Methods. J Phys Chem Lett 2018; 9:6185-6190. [PMID: 30299101 DOI: 10.1021/acs.jpclett.8b02733] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Neutral molecules with sufficiently large dipole moments can bind electrons in diffuse nonvalence orbitals with most of their charge density far from the nuclei, forming so-called dipole-bound anions. Because long-range correlation effects play an important role in the binding of an excess electron and overall binding energies are often only on the order of 10s-100s of wave numbers, predictively modeling dipole-bound anions remains a challenge. Here, we demonstrate that quantum Monte Carlo methods can accurately characterize molecular dipole-bound anions with near-threshold dipole moments. We also show that correlated sampling Auxiliary Field Quantum Monte Carlo is particularly well-suited for resolving the fine energy differences between the neutral and anionic species. These results shed light on the fundamental limitations of quantum Monte Carlo methods and pave the way toward using them for the study of weakly bound species that are too large to model using traditional electron structure methods.
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Affiliation(s)
- Hongxia Hao
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
| | - James Shee
- Department of Chemistry , Columbia University , New York , New York 10027 , United States
| | - Shiv Upadhyay
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Can Ataca
- Department of Physics , University of Maryland-Baltimore County , Baltimore , Maryland 21250 , United States
| | - Kenneth D Jordan
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Brenda M Rubenstein
- Department of Chemistry , Brown University , Providence , Rhode Island 02912 , United States
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87
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Zhu GZ, Qian CH, Wang LS. Dipole-bound excited states and resonant photoelectron imaging of phenoxide and thiophenoxide anions. J Chem Phys 2018; 149:164301. [DOI: 10.1063/1.5049715] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Affiliation(s)
- Guo-Zhu Zhu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Chen-Hui Qian
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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88
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Lee J, Head-Gordon M. Regularized Orbital-Optimized Second-Order Møller–Plesset Perturbation Theory: A Reliable Fifth-Order-Scaling Electron Correlation Model with Orbital Energy Dependent Regularizers. J Chem Theory Comput 2018; 14:5203-5219. [DOI: 10.1021/acs.jctc.8b00731] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joonho Lee
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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89
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Wang Y, Guo H, Zheng Q, Saidi WA, Zhao J. Tuning Solvated Electrons by Polar-Nonpolar Oxide Heterostructure. J Phys Chem Lett 2018; 9:3049-3056. [PMID: 29767527 DOI: 10.1021/acs.jpclett.8b00938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Solvated electron states at the oxide/aqueous interface represent the lowest energy charge-transfer pathways, thereby playing an important role in photocatalysis and electronic device applications. However, their energies are usually higher than the conduction band minimum (CBM), which makes the solvated electrons difficult to utilize in charge-transfer processes. Thus it is essential to stabilize the energy of the solvated electron states. Taking LaAlO3/SrTiO3 (LAO/STO) oxide heterostructure with H2O-adsorbed monolayer as a prototypical system, we show using DFT and ab initio time-dependent nonadiabatic molecular dynamics simulation that the energy and dynamics of solvated electrons can be tuned by the electric field in the polar-nonpolar oxide heterostructure. In particular, for LAO/STO with p-type interface, the CBM is contributed by the solvated electron state when LAO is thicker than four unit cells. Furthermore, the solvated electron band minimum can be partially occupied when LAO is thicker than eight unit cells. We propose that the tunability of solvated electron states can be achieved on polar-nonpolar oxide heterostructure surfaces as well as on ferroelectric oxides, which is important for charge and proton transfer at oxide/aqueous interfaces.
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Affiliation(s)
- Yanan Wang
- ICQD/Hefei National Laboratory for Physical Sciences at Microscale and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Hongli Guo
- ICQD/Hefei National Laboratory for Physical Sciences at Microscale and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
- School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education , Wuhan University , Wuhan 430072 , China
| | - Qijing Zheng
- ICQD/Hefei National Laboratory for Physical Sciences at Microscale and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
| | - Wissam A Saidi
- Department of Mechanical Engineering and Materials Science , University of Pittsburgh , Pittsburgh , Pennsylvania 15261 , United States
| | - Jin Zhao
- ICQD/Hefei National Laboratory for Physical Sciences at Microscale and Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences and Department of Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
- Department of Physics and Astronomy , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
- Synergetic Innovation Center of Quantum Information & Quantum Physics , University of Science and Technology of China , Hefei , Anhui 230026 , China
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90
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Rogers JP, Anstöter CS, Verlet JRR. Evidence of Electron Capture of an Outgoing Photoelectron Wave by a Nonvalence State in (C 6F 6) n. J Phys Chem Lett 2018; 9:2504-2509. [PMID: 29694047 DOI: 10.1021/acs.jpclett.8b00739] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Frequency-resolved photoelectron spectra are presented for (C6F6) n- with n = 1-5 that show that C6F6- is solvated by neutral C6F6 molecules. Direct photodetachment channels of C6F6- are observed for all n, leaving the neutral in the S0 ground state or triplet states, T1 and T2. For n ≥ 2, an additional indirect electron loss channel is observed when the triplet-state channels open. This indirect emission appears to arise from the electron capture of the outgoing photoelectron s-wave by a neutral solvent molecule through an anion nonvalence state. The same process is not observed for the S0 detachment channel because the outgoing electron wave is predominantly a p-wave. Our results show that anion nonvalence states can act as electron-accepting states in cluster environments and can be viewed as precursor states for diffuse states of liquid C6F6.
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Affiliation(s)
- Joshua P Rogers
- Department of Chemistry , Durham University , Durham DH1 3LE , United Kingdom
| | - Cate S Anstöter
- Department of Chemistry , Durham University , Durham DH1 3LE , United Kingdom
| | - Jan R R Verlet
- Department of Chemistry , Durham University , Durham DH1 3LE , United Kingdom
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91
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Green ML, Jean P, Heaven MC. Dative Bonding between Closed-Shell Atoms: The BeF - Anion. J Phys Chem Lett 2018; 9:1999-2002. [PMID: 29613801 DOI: 10.1021/acs.jpclett.8b00784] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Beryllium can exhibit unusually strong attractive interactions under conditions where it is nominally a closed-shell atom. Two prominent examples are the Be2 dimer and the He-BeO complex. In the present study, we examine the bonding of the closed-shell Be-F- anion. This molecule preserves the closed-shell character of the individual atoms as the electron affinity of F is high (328.16 kJ mol-1) while that of Be is negative. Photodetachment spectroscopy was used to determine the vibrational frequency for BeF- and the electron affinity of BeF (104.2 kJ mol-1). The latter has been used to determine a lower bound of 343 kJ mol-1 for the bond energy of BeF-. Electronic structure calculations yielded predictions that were in good agreement with the observed data. A natural bond orbital analysis shows that BeF- is primarily bound by a dative interaction.
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Affiliation(s)
- Mallory L Green
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Pearl Jean
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Michael C Heaven
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
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92
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Zhang C, Luo Q, Cheng S, Bu Y. Unusual Indirect Nuclear Spin-Spin Exchange Coupling through Solvated Electron. J Phys Chem Lett 2018; 9:689-695. [PMID: 29369635 DOI: 10.1021/acs.jpclett.7b03249] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Solvated electrons have been found to exist in various media which also exhibit more intriguing properties such as superconductivity, nonlinear optical response, and so on. However, how they affect the nuclear spin properties has not been proven. In this work, we present the first detailed study on solvated-electron-triggered indirect nuclear spin-spin J-coupling using density functional theory calculations. Taking 19F as a probe, we verify the presence of unusual J couplings between two distant F atoms in HF-containing anionic clusters. These couplings occur "through solvated electron", rather than through conventional covalent bonds or space. Solvated electron can serve as an additional channel to efficiently realize long-range J-coupling between far separated nuclei because of its dispersivity and Rydberg character. The coupling magnitude strongly depends on the unique distribution of solvated electron and its second-order interaction with solvating HF units. This work provides novel insights into the mediating roles of electrons, possibly opening up potential applications based on weakly bound electrons.
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Affiliation(s)
- Changzhe Zhang
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
| | - Qi Luo
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
| | - Shibo Cheng
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
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93
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Anionic Water Cluster Polymers [(H₂O) 18(OH)₂] n2n- Is Stabilized by Bis(2,2'-bipyridine) Cupric Chloride [Cu(bipy)₂Cl] . Molecules 2018; 23:molecules23010195. [PMID: 29351191 PMCID: PMC6017829 DOI: 10.3390/molecules23010195] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 01/10/2018] [Accepted: 01/12/2018] [Indexed: 11/17/2022] Open
Abstract
Anionic water clusters have long been studied to infer properties of the bulk hydrated electron. In particular, the question of whether the excess electron is on the surface of the cluster or in the interior of the clusters has been the subject of much speculation. The successes of solid-state physics are built on exploiting the regularity of atomic arrangements in crystal. Describing the crystalline order of solids is relatively straightforward. Here we report the crystal structure of an anionic water cluster polymer [(H₂O)18(OH)₂]n2n- moiety that is stabilized by bis(2,2'-bipyridine) cupric chloride [Cu(bipy)₂Cl]- host.
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94
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Ultrafast dynamics of low-energy electron attachment via a non-valence correlation-bound state. Nat Chem 2018; 10:341-346. [PMID: 29461530 DOI: 10.1038/nchem.2912] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/15/2017] [Indexed: 11/09/2022]
Abstract
The primary electron-attachment process in electron-driven chemistry represents one of the most fundamental chemical transformations with wide-ranging importance in science and technology. However, the mechanistic detail of the seemingly simple reaction of an electron and a neutral molecule to form an anion remains poorly understood, particularly at very low electron energies. Here, time-resolved photoelectron imaging was used to probe the electron-attachment process to a non-polar molecule using time-resolved methods. An initially populated diffuse non-valence state of the anion that is bound by correlation forces evolves coherently in ∼30 fs into a valence state of the anion. The extreme efficiency with which the correlation-bound state serves as a doorway state for low-energy electron attachment explains a number of electron-driven processes, such as anion formation in the interstellar medium and electron attachment to fullerenes.
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95
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Skomorowski W, Gulania S, Krylov AI. Bound and continuum-embedded states of cyanopolyyne anions. Phys Chem Chem Phys 2018; 20:4805-4817. [DOI: 10.1039/c7cp08227d] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Equation-of-motion coupled-cluster calculations reveal systematic trends across bound and continuum-embedded excited states in cyanopolyyne anions.
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Affiliation(s)
| | - Sahil Gulania
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
| | - Anna I. Krylov
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
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96
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Lyle J, Wedig O, Gulania S, Krylov AI, Mabbs R. Channel branching ratios in CH 2CN - photodetachment: Rotational structure and vibrational energy redistribution in autodetachment. J Chem Phys 2017; 147:234309. [PMID: 29272948 DOI: 10.1063/1.5001475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report photoelectron spectra of CH2CN-, recorded at photon energies between 13 460 and 15 384 cm-1, which show rapid intensity variations in particular detachment channels. The branching ratios for various spectral features reveal rotational structure associated with autodetachment from an intermediate anion state. Calculations using equation-of-motion coupled-cluster method with single and double excitations reveal the presence of two dipole-bound excited anion states (a singlet and a triplet). The computed oscillator strength for the transition to the singlet dipole-bound state provides an estimate of the autodetachment channel contribution to the total photoelectron yield. Analysis of the different spectral features allows identification of the dipole-bound and neutral vibrational levels involved in the autodetachment processes. For the most part, the autodetachment channels are consistent with the vibrational propensity rule and normal mode expectation. However, examination of the rotational structure shows that autodetachment from the ν3 (v = 1 and v = 2) levels of the dipole-bound state displays behavior counter to the normal mode expectation with the final state vibrational level belonging to a different mode.
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Affiliation(s)
- Justin Lyle
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Olivia Wedig
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Sahil Gulania
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Anna I Krylov
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Richard Mabbs
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, USA
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97
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Voora VK, Kairalapova A, Sommerfeld T, Jordan KD. Theoretical approaches for treating non-valence correlation-bound anions. J Chem Phys 2017; 147:214114. [DOI: 10.1063/1.4991497] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Vamsee K. Voora
- Department of Chemistry, University of California, Irvine, California 92697, USA
| | - Arailym Kairalapova
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Thomas Sommerfeld
- Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, Louisiana 70402, USA
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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98
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Choi TH, Vazhappilly T, Jordan KD. Implementation of analytical gradients and of a mixed real and momentum space DVR method for excess electron systems described by a self-consistent polarization model. J Chem Phys 2017; 147:161717. [DOI: 10.1063/1.4990396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Tae Hoon Choi
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Tijo Vazhappilly
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
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99
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Clark T. Polarization, donor-acceptor interactions, and covalent contributions in weak interactions: a clarification. J Mol Model 2017; 23:297. [PMID: 28956190 DOI: 10.1007/s00894-017-3473-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
Abstract
The concepts of polarization (induction), charge transfer and covalent bonding contributions are discussed in terms of weak interactions. They are shown to be different incarnations of the same phenomenon, so that using polarization to describe them is most consistent as it is the only real, measurable and uniquely defined quantity of the three. Dispersion is discussed as a form of polarization within the Feynman description. Model calculations are described. Graphical abstract The electron density of a hydride ion (nucleus white) polarized by a single positive point charge (brown).
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Affiliation(s)
- Timothy Clark
- Computer-Chemie-Centrum, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg, Nägelsbachstraße 25, 91052, Erlangen, Germany.
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100
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Zhu GZ, Liu Y, Wang LS. Observation of Excited Quadrupole-Bound States in Cold Anions. PHYSICAL REVIEW LETTERS 2017; 119:023002. [PMID: 28753341 DOI: 10.1103/physrevlett.119.023002] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Indexed: 06/07/2023]
Abstract
We report the first observation of an excited quadrupole-bound state (QBS) in an anion. High-resolution photoelectron imaging of cryogenically cooled 4-cyanophenoxide (4CP^{-}) anions yields an electron detachment threshold of 24 927 cm^{-1}. The photodetachment spectrum reveals a resonant transition 20 cm^{-1} below the detachment threshold, which is attributed to an excited QBS of 4CP^{-} because neutral 4CP has a large quadrupole moment with a negligible dipole moment. The QBS is confirmed by observation of seventeen above-threshold resonances due to autodetachment from vibrational levels of the QBS.
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Affiliation(s)
- Guo-Zhu Zhu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yuan Liu
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Lai-Sheng Wang
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
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