1
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Martin DC, Elg DT, Delgado HE, Nguyen HM, Rumbach P, Bartels DM, Go DB. Optical and Chemical Measurements of Solvated Electrons Produced in Plasma Electrolysis with a Water Cathode. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:14224-14232. [PMID: 38940536 DOI: 10.1021/acs.langmuir.4c00639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/29/2024]
Abstract
It is known that glow discharges with a water anode inject and form solvated electrons at the plasma-liquid interface, driving a wide variety of reduction reactions. However, in systems with a water cathode, the production and role of solvated electrons are less clear. Here, we present evidence for the direct detection of solvated electrons produced at the interface of an argon plasma and a water cathode via absorption spectroscopy. We further quantify their yield using the dissociative electron attachment of chloroacetate, measuring a yield of 1.04 ± 0.59 electrons per incident ion, corresponding to approximately 100% faradaic efficiency. Additionally, we estimate a yield of 2.09 ± 0.93 hydroxyl radicals per incident ion. Comparison of this yield with other findings in the literature supports that these hydroxyl radicals are likely formed directly in the liquid phase rather than by diffusion from the vapor phase.
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Affiliation(s)
- Daniel C Martin
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Daniel T Elg
- Department of Engineering, University of Southern Indiana, Evansville, Indiana 47712, United States
| | - Hernan E Delgado
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Hoang M Nguyen
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Paul Rumbach
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David M Bartels
- Notre Dame Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - David B Go
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
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2
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D-Kondo N, Ortiz R, Faddegon B, Incerti S, Tran HN, Francis Z, Barbosa EM, Schuemann J, Ramos-Méndez J. Lithium inelastic cross-sections and their impact on micro and nano dosimetry of boron neutron capture. Phys Med Biol 2024; 69:10.1088/1361-6560/ad5f72. [PMID: 38964312 PMCID: PMC11271803 DOI: 10.1088/1361-6560/ad5f72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 07/04/2024] [Indexed: 07/06/2024]
Abstract
Objective.To present a new set of lithium-ion cross-sections for (i) ionization and excitation processes down to 700 eV, and (ii) charge-exchange processes down to 1 keV u-1. To evaluate the impact of the use of these cross-sections on micro a nano dosimetric quantities in the context of boron neutron capture (BNC) applications/techniques.Approach.The Classical Trajectory Monte Carlo method was used to calculate Li ion charge-exchange cross sections in the energy range of 1 keV u-1to 10 MeV u-1. Partial Li ion charge states ionization and excitation cross-sections were calculated using a detailed charge screening factor. The cross-sections were implemented in Geant4-DNA v10.07 and simulations and verified using TOPAS-nBio by calculating stopping power and continuous slowing down approximation (CSDA) range against data from ICRU and SRIM. Further microdosimetric and nanodosimetric calculations were performed to quantify differences against other simulation approaches for low energy Li ions. These calculations were: lineal energy spectra (yf(y) andyd(y)), frequency mean lineal energyyF-, dose mean lineal energyyD-and ionization cluster size distribution analysis. Microdosimetric calculations were compared against a previous MC study that neglected charge-exchange and excitation processes. Nanodosimetric results were compared against pure ionization scaled cross-sections calculations.Main results.Calculated stopping power differences between ICRU and Geant4-DNA decreased from 33.78% to 6.9%. The CSDA range difference decreased from 621% to 34% when compared against SRIM calculations. Geant4-DNA/TOPAS calculated dose mean lineal energy differed by 128% from the previous Monte Carlo. Ionization cluster size frequency distributions for Li ions differed by 76%-344.11% for 21 keV and 2 MeV respectively. With a decrease in theN1within 9% at 10 keV and agreeing after the 100 keV. With the new set of cross-sections being able to better simulate low energy behaviors of Li ions.Significance.This work shows an increase in detail gained from the use of a more complete set of low energy cross-sections which include charge exchange processes. Significant differences to previous simulation results were found at the microdosimetric and nanodosimetric scales that suggest that Li ions cause less ionizations per path length traveled but with more energy deposits. Microdosimetry results suggest that the BNC's contribution to cellular death may be mainly due to alpha particle production when boron-based drugs are distributed in the cellular membrane and beyond and by Li when it is at the cell cytoplasm regions.
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Affiliation(s)
- Naoki D-Kondo
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, United States of America
| | - Ramon Ortiz
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, United States of America
| | - Bruce Faddegon
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, United States of America
| | - Sebastien Incerti
- University of Bordeaux, CNRS, LP2I, CENBG, UMR 5797, F-33170 Gradignan, France
| | - H. N. Tran
- University of Bordeaux, CNRS, LP2I, CENBG, UMR 5797, F-33170 Gradignan, France
| | - Z. Francis
- Department of Physics, Faculty of Sciences, Université Saint Joseph, Beirut, Lebanon
| | - Eduardo Moreno Barbosa
- Facultad de Ciencias Físico-Matemáticas, Benemérita Universidad Autónoma de Puebla, Puebla Mexico
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - José Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, United States of America
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3
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Hilal S, Melnik M, Ismagilov A, Tsypkin A, Kozlov S. Determination of plasma properties in liquid jets through time-resolved experiments on third harmonic reflection dynamics. OPTICS LETTERS 2024; 49:2990-2993. [PMID: 38824310 DOI: 10.1364/ol.524582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/02/2024] [Indexed: 06/03/2024]
Abstract
The study of plasma in liquid jets represents a significant area of research encompassing plasma science, dynamics, and properties. This paper presents experimental studies on plasma formation processes in liquid jets of water, ethanol, and isopropyl based on the dynamics of the third harmonic (TH) reflection from the induced plasma. Through time-resolved experiments, and theoretical estimations using the Keldysh theory, plasma properties including density and frequency for all three media are evaluated. Isopropyl demonstrates the highest values of the characteristics mentioned. These findings hold significant potential for advancing our understanding of plasma-based radiation sources, e.g., terahertz generation.
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4
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Li S, Lu L, Bhattacharyya S, Pearce C, Li K, Nienhuis ET, Doumy G, Schaller RD, Moeller S, Lin MF, Dakovski G, Hoffman DJ, Garratt D, Larsen KA, Koralek JD, Hampton CY, Cesar D, Duris J, Zhang Z, Sudar N, Cryan JP, Marinelli A, Li X, Inhester L, Santra R, Young L. Attosecond-pump attosecond-probe x-ray spectroscopy of liquid water. Science 2024; 383:1118-1122. [PMID: 38359104 DOI: 10.1126/science.adn6059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/06/2024] [Indexed: 02/17/2024]
Abstract
Attosecond-pump/attosecond-probe experiments have long been sought as the most straightforward method for observing electron dynamics in real time. Although there has been much success with overlapped near-infrared femtosecond and extreme ultraviolet attosecond pulses combined with theory, true attosecond-pump/attosecond-probe experiments have been limited. We used a synchronized attosecond x-ray pulse pair from an x-ray free-electron laser to study the electronic response to valence ionization in liquid water through all x-ray attosecond transient absorption spectroscopy (AX-ATAS). Our analysis showed that the AX-ATAS response is confined to the subfemtosecond timescale, eliminating any hydrogen atom motion and demonstrating experimentally that the 1b1 splitting in the x-ray emission spectrum is related to dynamics and is not evidence of two structural motifs in ambient liquid water.
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Affiliation(s)
- Shuai Li
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - Lixin Lu
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Swarnendu Bhattacharyya
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
| | - Carolyn Pearce
- Pacific Northwest National Laboratory, Richland, WA, USA
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, USA
| | - Kai Li
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, IL, USA
| | | | - Gilles Doumy
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
| | - R D Schaller
- Center for Nanoscale Materials, Argonne National Laboratory, Lemont, IL, USA
| | - S Moeller
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - M-F Lin
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - G Dakovski
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D J Hoffman
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D Garratt
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Kirk A Larsen
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - J D Koralek
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - C Y Hampton
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - D Cesar
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Joseph Duris
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Z Zhang
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Nicholas Sudar
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - James P Cryan
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - A Marinelli
- SLAC National Accelerator Laboratory, Menlo Park, CA, USA
- Stanford PULSE Institute, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Xiaosong Li
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Ludger Inhester
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
| | - Robin Santra
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- The Hamburg Centre for Ultrafast Imaging, Hamburg, Germany
- Department of Physics, Universität Hamburg, Hamburg, Germany
| | - Linda Young
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, IL, USA
- Department of Physics and James Franck Institute, The University of Chicago, Chicago, IL, USA
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5
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He L, Tomaník L, Malerz S, Trinter F, Trippel S, Belina M, Slavíček P, Winter B, Küpper J. Specific versus Nonspecific Solvent Interactions of a Biomolecule in Water. J Phys Chem Lett 2023; 14:10499-10508. [PMID: 37970807 PMCID: PMC10683073 DOI: 10.1021/acs.jpclett.3c01763] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 08/23/2023] [Indexed: 11/19/2023]
Abstract
Solvent interactions, particularly hydration, are vital in chemical and biochemical systems. Model systems reveal microscopic details of such interactions. We uncover a specific hydrogen-bonding motif of the biomolecular building block indole (C8H7N), tryptophan's chromophore, in water: a strong localized N-H···OH2 hydrogen bond, alongside unstructured solvent interactions. This insight is revealed from a combined experimental and theoretical analysis of the electronic structure of indole in aqueous solution. We recorded the complete X-ray photoemission and Auger spectrum of aqueous-phase indole, quantitatively explaining all peaks through ab initio modeling. The efficient and accurate technique for modeling valence and core photoemission spectra involves the maximum-overlap method and the nonequilibrium polarizable-continuum model. A two-hole electron-population analysis quantitatively describes the Auger spectra. Core-electron binding energies for nitrogen and carbon highlight the specific interaction with a hydrogen-bonded water molecule at the N-H group and otherwise nonspecific solvent interactions.
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Affiliation(s)
- Lanhai He
- Center
for Free-Electron Laser Science, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- Institute
of Atomic and Molecular Physics, Jilin University, 130012 Changchun, China
| | - Lukáš Tomaník
- Department
of Physical Chemistry, University of Chemistry
and Technology, Technická 5, 16628 Prague, Czech Republic
| | - Sebastian Malerz
- Molecular
Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Florian Trinter
- Molecular
Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
- Institut
für Kernphysik, Goethe-Universität
Frankfurt, Max-von-Laue-Straße
1, 60438 Frankfurt
am Main, Germany
| | - Sebastian Trippel
- Center
for Free-Electron Laser Science, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- Center
for Ultrafast Imaging, Universität
Hamburg, Luruper Chaussee
149, 22761 Hamburg, Germany
| | - Michal Belina
- Department
of Physical Chemistry, University of Chemistry
and Technology, Technická 5, 16628 Prague, Czech Republic
| | - Petr Slavíček
- Department
of Physical Chemistry, University of Chemistry
and Technology, Technická 5, 16628 Prague, Czech Republic
| | - Bernd Winter
- Molecular
Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - Jochen Küpper
- Center
for Free-Electron Laser Science, Deutsches
Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg, Germany
- Center
for Ultrafast Imaging, Universität
Hamburg, Luruper Chaussee
149, 22761 Hamburg, Germany
- Department
of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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6
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Yin Z, Chang YP, Balčiūnas T, Shakya Y, Djorović A, Gaulier G, Fazio G, Santra R, Inhester L, Wolf JP, Wörner HJ. Femtosecond proton transfer in urea solutions probed by X-ray spectroscopy. Nature 2023; 619:749-754. [PMID: 37380782 PMCID: PMC10371863 DOI: 10.1038/s41586-023-06182-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 05/09/2023] [Indexed: 06/30/2023]
Abstract
Proton transfer is one of the most fundamental events in aqueous-phase chemistry and an emblematic case of coupled ultrafast electronic and structural dynamics1,2. Disentangling electronic and nuclear dynamics on the femtosecond timescales remains a formidable challenge, especially in the liquid phase, the natural environment of biochemical processes. Here we exploit the unique features of table-top water-window X-ray absorption spectroscopy3-6 to reveal femtosecond proton-transfer dynamics in ionized urea dimers in aqueous solution. Harnessing the element specificity and the site selectivity of X-ray absorption spectroscopy with the aid of ab initio quantum-mechanical and molecular-mechanics calculations, we show how, in addition to the proton transfer, the subsequent rearrangement of the urea dimer and the associated change of the electronic structure can be identified with site selectivity. These results establish the considerable potential of flat-jet, table-top X-ray absorption spectroscopy7,8 in elucidating solution-phase ultrafast dynamics in biomolecular systems.
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Affiliation(s)
- Zhong Yin
- Laboratory of Physical Chemistry, ETH Zürich, Zurich, Switzerland.
- International Center for Synchrotron Radiation Innovation Smart, Tohoku University, Miyagi, Sendai, Japan.
| | - Yi-Ping Chang
- GAP-Biophotonics, Université de Genève, Geneva, Switzerland
- European XFEL, Schenefeld, Germany
| | - Tadas Balčiūnas
- Laboratory of Physical Chemistry, ETH Zürich, Zurich, Switzerland
- GAP-Biophotonics, Université de Genève, Geneva, Switzerland
| | - Yashoj Shakya
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- Department of Physics, Universität Hamburg, Hamburg, Germany
| | | | | | - Giuseppe Fazio
- Laboratory of Physical Chemistry, ETH Zürich, Zurich, Switzerland
| | - Robin Santra
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany
- Department of Physics, Universität Hamburg, Hamburg, Germany
- Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany
| | - Ludger Inhester
- Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany.
- Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg, Germany.
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7
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Reshetnyak I, Lorin A, Pasquarello A. Many-body screening effects in liquid water. Nat Commun 2023; 14:2705. [PMID: 37169764 PMCID: PMC10175292 DOI: 10.1038/s41467-023-38420-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 04/27/2023] [Indexed: 05/13/2023] Open
Abstract
The screening arising from many-body excitations is a crucial quantity for describing absorption and inelastic X-ray scattering (IXS) of materials. Similarly, the electron screening plays a critical role in state-of-the-art approaches for determining the fundamental band gap. However, ab initio studies of the screening in liquid water have remained limited. Here, we use a combined analysis based on the Bethe-Salpeter equation and time-dependent density functional theory. We first show that absorption spectra at near-edge energies are insufficient to assess the accuracy by which the screening is described. Next, when the energy range under scrutiny is extended, we instead find that the IXS spectra are highly sensitive and allow for the selection of the optimal theoretical scheme. This leads to good agreement with experiment over a large range of transferred energies and momenta, and enables establishing the elusive fundamental band gap of liquid water at 9.3 eV.
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Affiliation(s)
- Igor Reshetnyak
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Arnaud Lorin
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland
| | - Alfredo Pasquarello
- Chaire de Simulation à l'Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
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8
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The Boundary between Two Modes of Gas Evolution: Oscillatory (H2 and O2) and Conventional Redox (O2 Only), in the Hydrocarbon/H2O2/Cu(II)/CH3CN System. HYDROGEN 2023. [DOI: 10.3390/hydrogen4010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
During the oxidation of hydrocarbons using hydrogen peroxide solutions, the evolution of gaseous oxygen is a side and undesirable process, in which the consumption of the oxidizer is not associated with the formation of target products. Therefore, no attention is paid to the systematic study of the chemical composition of the gas and the mechanisms of its formation. Filling this gap, the authors discovered a number of new, previously unidentified, interesting facts concerning both gas evolution and the oxidation of hydrocarbons. In a 33% H2O2/Cu2Cl4·2DMG/CH3CN system, where DMG is dimethylglyoxime (Butane-2,3-dione dioxime), and is at 50 °C, evidence of significant evolution of gaseous hydrogen, along with the evolution of gaseous oxygen was found. In the authors’ opinion, which requires additional verification, the ratio of gaseous hydrogen and oxygen in the discussed catalytic system can reach up to 1:1. The conditions in which only gaseous oxygen is formed are selected. Using a number of oxidizable hydrocarbons with the first adiabatic ionization potentials (AIPs) of a wide range of values, it was found that the first stage of such a process of evolving only gaseous oxygen was the single electron transfer from hydrogen peroxide molecules to trinuclear copper clusters with the formation, respectively, of hydrogen peroxide radical cations H2O2•+ and radical anions Cu3Cl5•− (AIP = 5 eV). When the conditions for the implementation of such a single electron transfer mechanism are exhausted, the channel of decomposition of hydrogen peroxide molecules into gaseous hydrogen and oxygen is switched on, which is accompanied by the transition of the system to an oscillatory mode of gas evolution. In some cases, the formation of additional amounts of gaseous products is provided by the catalytically activated decomposition of water molecules into hydrogen and oxygen after the complete consumption of hydrogen peroxide molecules in the reaction of gaseous oxygen evolution. The adiabatic electron affinity of various forms of copper molecules involved in chemical processes is calculated by the density functional theory method.
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9
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Abstract
Knowledge of the electronic structure of an aqueous solution is a prerequisite to understanding its chemical and biological reactivity and its response to light. One of the most direct ways of determining electronic structure is to use photoelectron spectroscopy to measure electron binding energies. Initially, photoelectron spectroscopy was restricted to the gas or solid phases due to the requirement for high vacuum to minimize inelastic scattering of the emitted electrons. The introduction of liquid-jets and their combination with intense X-ray sources at synchrotrons in the late 1990s expanded the scope of photoelectron spectroscopy to include liquids. Liquid-jet photoelectron spectroscopy is now an active research field involving a growing number of research groups. A limitation of X-ray photoelectron spectroscopy of aqueous solutions is the requirement to use solutes with reasonably high concentrations in order to obtain photoelectron spectra with adequate signal-to-noise after subtracting the spectrum of water. This has excluded most studies of organic molecules, which tend to be only weakly soluble. A solution to this problem is to use resonance-enhanced photoelectron spectroscopy with ultraviolet (UV) light pulses (hν ≲ 6 eV). However, the development of UV liquid-jet photoelectron spectroscopy has been hampered by a lack of quantitative understanding of inelastic scattering of low kinetic energy electrons (≲5 eV) and the impact on spectral lineshapes and positions.In this Account, we describe the key steps involved in the measurement of UV photoelectron spectra of aqueous solutions: photoionization/detachment, electron transport of low kinetic energy electrons through the conduction band, transmission through the water-vacuum interface, and transport through the spectrometer. We also explain the steps we take to record accurate UV photoelectron spectra of liquids with excellent signal-to-noise. We then describe how we have combined Monte Carlo simulations of electron scattering and spectral inversion with molecular dynamics simulations of depth profiles of organic solutes in aqueous solution to develop an efficient and widely applicable method for retrieving true UV photoelectron spectra of aqueous solutions. The huge potential of our experimental and spectral retrieval methods is illustrated using three examples. The first is a measurement of the vertical detachment energy of the green fluorescent protein chromophore, a sparingly soluble organic anion whose electronic structure underpins its fluorescence and photooxidation properties. The second is a measurement of the vertical ionization energy of liquid water, which has been the subject of discussion since the first X-ray photoelectron spectroscopy measurement in 1997. The third is a UV photoelectron spectroscopy study of the vertical ionization energy of aqueous phenol which demonstrates the possibility of retrieving true photoelectron spectra from measurements with contributions from components with different concentration profiles.
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10
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Different timescales during ultrafast stilbene isomerization in the gas and liquid phases revealed using time-resolved photoelectron spectroscopy. Nat Chem 2022; 14:1126-1132. [PMID: 35953643 PMCID: PMC7613649 DOI: 10.1038/s41557-022-01012-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 06/28/2022] [Indexed: 11/08/2022]
Abstract
Directly contrasting ultrafast excited-state dynamics in the gas and liquid phases is crucial to understanding the influence of complex environments. Previous studies have often relied on different spectroscopic observables, rendering direct comparisons challenging. Here, we apply extreme-ultraviolet time-resolved photoelectron spectroscopy to both gaseous and liquid cis-stilbene, revealing the coupled electronic and nuclear dynamics that underlie its isomerization. Our measurements track the excited-state wave packets from excitation along the complete reaction path to the final products. We observe coherent excited-state vibrational dynamics in both phases of matter that persist to the final products, enabling the characterization of the branching space of the S1-S0 conical intersection. We observe a systematic lengthening of the relaxation timescales in the liquid phase and a red shift of the measured excited-state frequencies that is most pronounced for the complex reaction coordinate. These results characterize in detail the influence of the liquid environment on both electronic and structural dynamics during a complete photochemical transformation.
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11
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Scholz M, Fortune WG, Tau O, Fielding HH. Accurate Vertical Ionization Energy of Water and Retrieval of True Ultraviolet Photoelectron Spectra of Aqueous Solutions. J Phys Chem Lett 2022; 13:6889-6895. [PMID: 35862937 PMCID: PMC9358712 DOI: 10.1021/acs.jpclett.2c01768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/14/2022] [Indexed: 05/23/2023]
Abstract
Ultraviolet (UV) photoelectron spectroscopy provides a direct way of measuring valence electronic structure; however, its application to aqueous solutions has been hampered by a lack of quantitative understanding of how inelastic scattering of low-energy (<5 eV) electrons in liquid water distorts the measured electron kinetic energy distributions. Here, we present an efficient and widely applicable method for retrieving true UV photoelectron spectra of aqueous solutions. Our method combines Monte Carlo simulations of electron scattering and spectral inversion, with molecular dynamics simulations of depth profiles of organic solutes in aqueous solution. Its application is demonstrated for both liquid water, and aqueous solutions of phenol and phenolate, which are ubiquitous biologically relevant structural motifs.
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12
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Choi JW, Choi JY, Jang H, Joo KK, Kim BC. Pixel Image Analysis and Its Application with an Alcohol-Based Liquid Scintillator for Particle Therapy. SENSORS (BASEL, SWITZERLAND) 2022; 22:4876. [PMID: 35808370 PMCID: PMC9269500 DOI: 10.3390/s22134876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/09/2022] [Accepted: 06/23/2022] [Indexed: 06/15/2023]
Abstract
We synthesized an alcohol-based liquid scintillator (AbLS), and we implemented an auxiliary monitoring system with short calibration intervals using AbLS for particle therapy. The commercial liquid scintillator used in previous studies did not allow the user to control the chemical ratio and its composition. In our study, the chemical ratio of AbLS was freely controlled by simultaneously mixing water and alcohol. To make an equivalent substance to the human body, 2-ethoxyethanol was used. There was no significant difference between AbLS and water in areal density. As an application of AbLS, the range was measured with AbLS using an electron beam in an image analysis that combined AbLS and a digital phone camera. Given a range-energy relationship for the electron expressed as areal density, the electron beam range (cm) in water can be easily estimated. To date, no literature report for the direct comparison of a pixel image analysis and Monte Carlo (MC) simulation has been published. Furthermore, optical tomography of the inverse problem was performed with AbLS and a mobile phone camera. Analyses of optical tomography images provide deeper insight into Radon transformation. In addition, the human phantom, which is difficult to compose with semiconductor diodes, was easily implemented as an image acquisition and analysis system.
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Affiliation(s)
- Ji-Won Choi
- Institute for Universe & Elementary Particles, Department of Physics, Chonnam National University, Yongbong-ro 77, Puk-gu, Gwangju 61186, Korea;
| | - Ji-Young Choi
- Department of Fire Safety, Seoyeong University, Seogang-ro 1, Puk-gu, Gwangju 61268, Korea;
| | - Hanil Jang
- Department of Fire Safety, Seoyeong University, Seogang-ro 1, Puk-gu, Gwangju 61268, Korea;
| | - Kyung-Kwang Joo
- Institute for Universe & Elementary Particles, Department of Physics, Chonnam National University, Yongbong-ro 77, Puk-gu, Gwangju 61186, Korea;
| | - Byoung-Chan Kim
- Medical Radiation, Wonkwang Health Science University, 514, Iksan-daero, Iksan-si 54538, Korea
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13
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Signorell R, Winter B. Photoionization of the aqueous phase: clusters, droplets and liquid jets. Phys Chem Chem Phys 2022; 24:13438-13460. [PMID: 35510623 PMCID: PMC9176186 DOI: 10.1039/d2cp00164k] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
This perspective article reviews specific challenges associated with photoemission spectroscopy of bulk liquid water, aqueous solutions, water droplets and water clusters. The main focus lies on retrieving accurate energetics and photoelectron angular information from measured photoemission spectra, and on the question how these quantities differ in different aqueous environments. Measured photoelectron band shapes, vertical binding energies (ionization energies), and photoelectron angular distributions are influenced by various phenomena. We discuss the influences of multiple energy-dependent electron scattering in aqueous environments, and we discuss different energy referencing methods, including the application of a bias voltage to access absolute energetics of solvent and solute. Recommendations how to account for or minimize the influence of electron scattering are provided. The example of the hydrated electron in different aqueous environments illustrates how one can account for electron scattering, while reliable methods addressing parasitic potentials and proper energy referencing are demonstrated for ionization from the outermost valence orbital of neat liquid water. This perspective article reviews specific challenges associated with photoemission spectroscopy of bulk liquid water, aqueous solutions, water droplets and water clusters.![]()
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Affiliation(s)
- Ruth Signorell
- Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland.
| | - Bernd Winter
- Molecular Physics Department, Fritz-Haber-Institute der Max-Planck-Gesellschaft, Faradayweg 4-6, 14196 Berlin, Germany.
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14
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Zhang P, Perry C, Luu TT, Matselyukh D, Wörner HJ. Intermolecular Coulombic Decay in Liquid Water. PHYSICAL REVIEW LETTERS 2022; 128:133001. [PMID: 35426704 DOI: 10.1103/physrevlett.128.133001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 02/09/2022] [Accepted: 02/11/2022] [Indexed: 06/14/2023]
Abstract
We report the first observation of intermolecular Coulombic decay (ICD) in liquid water following inner-valence ionization. By combining a monochromatized tabletop high-harmonic source with a liquid microjet, we record electron-electron coincidence spectra at two photon energies that identify the ICD electrons, together with the photoelectrons originating from the 2a_{1} inner-valence band of liquid water. Our results confirm the importance of ICD as a source of low-energy electrons in bulk liquid water and provide quantitative results for modeling the velocity distribution of the slow electrons that are thought to dominate radiation damage in aqueous environments.
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Affiliation(s)
- Pengju Zhang
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Conaill Perry
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Tran Trung Luu
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
- Department of Physics, The University of Hong Kong, Pokfulam Road, SAR Hong Kong, People's Republic of China
| | - Danylo Matselyukh
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
| | - Hans Jakob Wörner
- Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland
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15
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Shepard C, Kanai Y. Nonlinear electronic excitation in water under proton irradiation: a first principles study. Phys Chem Chem Phys 2022; 24:5598-5603. [PMID: 35175259 DOI: 10.1039/d1cp05313b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nonlinear dynamics of electronic excitation bridge physical and physicochemical stages of water radiolysis under proton irradiation, a multi-scale physicochemical process that is fundamental to a wide range of technological and medical applications of high-energy protons. We study the spatial and temporal changes to the excited holes generated in this ionization event using first-principles theory simulation. A significant majority of holes are formed in the immediate vicinity of the irradiating proton paths, and these holes decay rapidly, while secondary excitations are simultaneously induced in regions farther away. While the hole population remains constant, the observed spatially spreading hole distribution cannot be described as concentration-dependent diffusion current. Compared to the primary excitation induced by the irradiating protons, the secondary excitation farther away is somewhat less energetic. The first-principles theory simulation here provides a detailed description of how the primary excitation by proton radiation precedes the formation of cationic holes, which undergo ultrafast chemical processes in water radiolysis.
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Affiliation(s)
- Christopher Shepard
- Department of Chemistry, University of North Carolina at Chapel Hill, NC, USA.
| | - Yosuke Kanai
- Department of Chemistry, University of North Carolina at Chapel Hill, NC, USA.
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16
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Poštulka J, Slavíček P, Pysanenko A, Poterya V, Fárník M. Bimolecular reactions on sticky and slippery clusters: Electron-induced reactions of hydrogen peroxide. J Chem Phys 2022; 156:054306. [DOI: 10.1063/5.0079283] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Jan Poštulka
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague, Czech Republic
| | - Petr Slavíček
- Department of Physical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 16628 Prague, Czech Republic
| | - Andriy Pysanenko
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 2155/3, Prague 8, Czech Republic
| | - Viktoriya Poterya
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 2155/3, Prague 8, Czech Republic
| | - Michal Fárník
- J. Heyrovský Institute of Physical Chemistry, Czech Academy of Sciences, Dolejškova 2155/3, Prague 8, Czech Republic
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17
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Gadeyne T, Zhang P, Schild A, Wörner HJ. Low-energy electron distributions from the photoionization of liquid water: a sensitive test of electron mean-free paths. Chem Sci 2022; 13:1675-1692. [PMID: 35282614 PMCID: PMC8826766 DOI: 10.1039/d1sc06741a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 01/06/2022] [Indexed: 11/21/2022] Open
Abstract
The availability of accurate mean free paths for slow electrons (<50 eV) in water is central to the understanding of many electron-driven processes in aqueous solutions, but their determination poses major challenges to experiment and theory alike. Here, we describe a joint experimental and theoretical study demonstrating a novel approach for testing, and, in the future, refining such mean free paths. We report the development of Monte-Carlo electron-trajectory simulations including elastic and inelastic electron scattering, as well as energy loss and secondary-electron production to predict complete photoelectron spectra of liquid water. These simulations are compared to a new set of photoelectron spectra of a liquid-water microjet recorded over a broad range of photon energies in the extreme ultraviolet (20–57 eV). Several previously published sets of scattering parameters are investigated, providing direct and intuitive insights on how they influence the shape of the low-energy electron spectra. A pronounced sensitivity to the escape barrier is also demonstrated. These simulations considerably advance our understanding of the origin of the prominent low-energy electron distributions in photoelectron spectra of liquid water and clarify the influence of scattering parameters and the escape barrier on their shape. They moreover describe the reshaping and displacement of low-energy photoelectron bands caused by vibrationally inelastic scattering. Our work provides a quantitative basis for the interpretation of the complete photoelectron spectra of liquids and opens the path to fully predictive simulations of low-energy scattering in liquid water. Our study reveals the detailed influence of elastic and inelastic mean-free paths on the complete photoelectron spectra of liquid water, including the low-energy electron distributions and the reshaping of the primary photoelectron bands.![]()
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Affiliation(s)
- Titouan Gadeyne
- Laboratory for Physical Chemistry, ETH Zürich Vladimir-Prelog-Weg 2 8093 Zürich Switzerland
- Département de Chimie, École Normale Supérieure, PSL University 75005 Paris France
| | - Pengju Zhang
- Laboratory for Physical Chemistry, ETH Zürich Vladimir-Prelog-Weg 2 8093 Zürich Switzerland
| | - Axel Schild
- Laboratory for Physical Chemistry, ETH Zürich Vladimir-Prelog-Weg 2 8093 Zürich Switzerland
| | - Hans Jakob Wörner
- Laboratory for Physical Chemistry, ETH Zürich Vladimir-Prelog-Weg 2 8093 Zürich Switzerland
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18
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Eguchi K, Murata H. Evolution of the Ionization Energy in Two- and Three-Dimensional Thin Films of Pentacene Grown on Silicon Oxide Surfaces. J Phys Chem Lett 2021; 12:9407-9412. [PMID: 34553941 DOI: 10.1021/acs.jpclett.1c02723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The ionization energy (IE) of pentacene in two- and three-dimensional (2D and 3D) thin films and its evolution with coverage were studied via photoelectron yield spectroscopy in ambient conditions. In the 2D thin films, the IE of pentacene was found to be nearly constant at 4.91 eV, irrespective of its island size, for an average island size exceeding 1.6 × 104 nm2. In the 3D thin films, however, a reduction in IE by 0.04 eV was clearly observed upon stacking an additional molecular layer on top of the monolayer film, and the IE decreased to 4.73 eV at 20 monolayers. These experimental findings demonstrate the IE evolution in the buried layers of the 3D thin films and the significant impact of the neighboring molecular layers on the IE in layered systems with molecular aggregation.
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Affiliation(s)
- Keitaro Eguchi
- School of Materials Sciences, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan
| | - Hideyuki Murata
- School of Materials Sciences, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan
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19
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Bin Mohd Yusof MS, Lim YL, Loh ZH. Ultrafast vibrational wave packet dynamics of the aqueous tyrosyl radical anion induced by photodetachment. Phys Chem Chem Phys 2021; 23:18525-18534. [PMID: 34581329 DOI: 10.1039/d1cp02975d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The ultrafast dynamics triggered by the photodetachment of the tyrosinate dianion in aqueous environment shed light on the elementary processes that accompany the interaction of ionizing radiation with biological matter. Photodetachment of the tryosinate dianion yields the tyrosyl radical anion, an important intermediate in biological redox reactions, although the study of its ultrafast dynamics is limited. Here, we utilize femtosecond optical pump-probe spectroscopy to investigate the ultrafast structural reorganization dynamics that follow the photodetachment of the tyrosinate dianion in aqueous solution. Photodetachment of the tyrosinate dianion leads to vibrational wave packet motion along seven vibrational modes that are coupled to the photodetachment process. The vibrational modes are assigned with the aid of density functional theory (DFT) calculations. Our results offer a glimpse of the elementary dynamics of ionized biomolecules and suggest the possibility of extending this approach to investigate the ionization-induced structural rearrangement of other aromatic amino acids and larger biomolecules.
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Affiliation(s)
- Muhammad Shafiq Bin Mohd Yusof
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Yong Liang Lim
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
| | - Zhi-Heng Loh
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.
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20
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Thürmer S, Malerz S, Trinter F, Hergenhahn U, Lee C, Neumark DM, Meijer G, Winter B, Wilkinson I. Accurate vertical ionization energy and work function determinations of liquid water and aqueous solutions. Chem Sci 2021; 12:10558-10582. [PMID: 34447550 PMCID: PMC8356740 DOI: 10.1039/d1sc01908b] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/02/2021] [Indexed: 01/29/2023] Open
Abstract
The absolute-scale electronic energetics of liquid water and aqueous solutions, both in the bulk and at associated interfaces, are the central determiners of water-based chemistry. However, such information is generally experimentally inaccessible. Here we demonstrate that a refined implementation of the liquid microjet photoelectron spectroscopy (PES) technique can be adopted to address this. Implementing concepts from condensed matter physics, we establish novel all-liquid-phase vacuum and equilibrated solution–metal-electrode Fermi level referencing procedures. This enables the precise and accurate determination of previously elusive water solvent and solute vertical ionization energies, VIEs. Notably, this includes quantification of solute-induced perturbations of water's electronic energetics and VIE definition on an absolute and universal chemical potential scale. Defining and applying these procedures over a broad range of ionization energies, we accurately and respectively determine the VIE and oxidative stability of liquid water as 11.33 ± 0.03 eV and 6.60 ± 0.08 eV with respect to its liquid-vacuum-interface potential and Fermi level. Combining our referencing schemes, we accurately determine the work function of liquid water as 4.73 ± 0.09 eV. Further, applying our novel approach to a pair of exemplary aqueous solutions, we extract absolute VIEs of aqueous iodide anions, reaffirm the robustness of liquid water's electronic structure to high bulk salt concentrations (2 M sodium iodide), and quantify reference-level dependent reductions of water's VIE and a 0.48 ± 0.13 eV contraction of the solution's work function upon partial hydration of a known surfactant (25 mM tetrabutylammonium iodide). Our combined experimental accomplishments mark a major advance in our ability to quantify electronic–structure interactions and chemical reactivity in liquid water, which now explicitly extends to the measurement of absolute-scale bulk and interfacial solution energetics, including those of relevance to aqueous electrochemical processes. A generalised liquid-phase photoelectron spectroscopy approach is reported, allowing accurate, absolute energy scale ionisation energies of liquid water and aqueous solutions, as well as liquid water's work function to be reported.![]()
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Affiliation(s)
- Stephan Thürmer
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-Ku Kyoto 606-8502 Japan
| | - Sebastian Malerz
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 14195 Berlin Germany
| | - Florian Trinter
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 14195 Berlin Germany .,Institut für Kernphysik, Goethe-Universität Max-von-Laue-Straße 1 60438 Frankfurt am Main Germany
| | - Uwe Hergenhahn
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 14195 Berlin Germany
| | - Chin Lee
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 14195 Berlin Germany .,Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA.,Department of Chemistry, University of California Berkeley CA 94720 USA
| | - Daniel M Neumark
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA.,Department of Chemistry, University of California Berkeley CA 94720 USA
| | - Gerard Meijer
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 14195 Berlin Germany
| | - Bernd Winter
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft Faradayweg 4-6 14195 Berlin Germany
| | - Iain Wilkinson
- Department of Locally-Sensitive & Time-Resolved Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie Hahn-Meitner-Platz 1 14109 Berlin Germany
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21
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Pérez Ramírez L, Boucly A, Saudrais F, Bournel F, Gallet JJ, Maisonhaute E, Milosavljević AR, Nicolas C, Rochet F. The Fermi level as an energy reference in liquid jet X-ray photoelectron spectroscopy studies of aqueous solutions. Phys Chem Chem Phys 2021; 23:16224-16233. [PMID: 34304262 DOI: 10.1039/d1cp01511g] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
To advance the understanding of key electrochemical and photocatalytic processes that depend on the electronic structure of aqueous solutions, X-ray photoemission spectroscopy has become an invaluable tool, especially when practiced with liquid microjet setups. Determining vertical ionization energies referenced to the vacuum level, and binding energies referenced to the Fermi level, including the much-coveted reorganization energy of the oxidized species of a redox couple, requires that energy levels be properly defined. The present paper addresses specifically how the vacuum level "just outside the surface" can be known through the energy position of the rising edge of the secondary electrons, and how the Fermi level reference is uniquely determined via the introduction of a redox couple. Taking the case of the ferricyanide/ferrocyanide and ferric/ferrous couples, this study also tackles issues related to the electrokinetic effects inherent to the production of a liquid jet in a vacuum, which has become the standard water sample environment for photoemission experiments.
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Affiliation(s)
- Lucía Pérez Ramírez
- Sorbonne Université, CNRS, Laboratoire de Chimie Physique Matière et Rayonnement, UMR 7614, 4 Place Jussieu, 75005 Paris, France.
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22
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Paul SK, Herbert JM. Probing Interfacial Effects on Ionization Energies: The Surprising Banality of Anion-Water Hydrogen Bonding at the Air/Water Interface. J Am Chem Soc 2021; 143:10189-10202. [PMID: 34184532 DOI: 10.1021/jacs.1c03131] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Liquid microjet photoelectron spectroscopy is an increasingly common technique to measure vertical ionization energies (VIEs) of aqueous solutes, but the interpretation of these experiments is subject to questions regarding sensitivity to bulk versus interfacial solvation environments. We have computed aqueous-phase VIEs for a set of inorganic anions, using a combination of molecular dynamics simulations and electronic structure calculations, with results that are in excellent agreement with experiment regardless of whether the simulation data are restricted to ions at the air/water interface or to those in bulk aqueous solution. Although the computed VIEs are sensitive to ion-water hydrogen bonding, we find that the short-range solvation structure is sufficiently similar in both environments that it proves impossible to discriminate between the two on the basis of the VIE, a conclusion that has important implications for the interpretation of liquid-phase photoelectron spectroscopy. More generally, analysis of the simulation data suggests that the surface activity of soft anions is largely a second or third solvation shell effect, arising from disruption of water-water hydrogen bonds and not from significant changes in first-shell anion-water hydrogen bonding.
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Affiliation(s)
- Suranjan K Paul
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - John M Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
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23
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Immunocytochemical Localization of XRCC1 and γH2AX Foci Induced by Tightly Focused Femtosecond Laser Radiation in Cultured Human Cells. Molecules 2021; 26:molecules26134027. [PMID: 34279367 PMCID: PMC8271364 DOI: 10.3390/molecules26134027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/29/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
To assess the prospects for using intense femtosecond laser radiation in biomedicine, it is necessary to understand the mechanisms of its action on biological macromolecules, especially on the informational macromolecule-DNA. The aim of this work was to study the immunocytochemical localization of DNA repair protein foci (XRCC1 and γH2AX) induced by tightly focused femtosecond laser radiation in human cancer A549 cells. The results showed that no XRCC1 or γH2AX foci tracks were observed 30 min after cell irradiation with femtosecond pulses of 1011 W∙cm-2 peak power density. An increase in the pulse power density to 2 × 1011 W∙cm-2 led to the formation of linear tracks consisting both of XRCC1 and γH2AX protein foci localized in the places where the laser beam passed through the cell nuclei. A further increase in the pulse power density to 4 × 1011 W∙cm-2 led to the appearance of nuclei with total immunocytochemical staining for XRCC1 and γH2AX on the path of the laser beam. Thus, femtosecond laser radiation can be considered as a tool for local ionization of biological material, and this ionization will lead to similar effects obtained using ionizing radiation.
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24
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Tao X, Nie J, Li S, Shi Y, Lin S, Chen X, Wang ZL. Effect of Photo-Excitation on Contact Electrification at Liquid-Solid Interface. ACS NANO 2021; 15:10609-10617. [PMID: 34101417 DOI: 10.1021/acsnano.1c03358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Liquid-solid triboelectric nanogenerator (L-S TENG) is one of the major techniques to collect energy from tiny liquids, while the saturated charge density at the L-S interface is the key element to decide its performance. Here, we found that the saturated charge density of L-S contact electrification (CE) can be further increased under the illumination of an ultraviolet (UV) light. The fluorine-containing polymers and SiO2 are chosen as the electrification materials and with and without UV illumination on the L-S TENG. A series of experiments have been done to rule out the possible influences of anion generation, chemical change of solid surface, ionization of water, and so on. Therefore, we proposed that electrons belonging to water molecules can be excited to high energy states under UV illumination, which then transfer to solid surface and captured by the solid surface. Finally, a photoexcited electron transfer model is proposed to explain the enhancement of CE under the UV illumination. This work not only helps to further understand CE at L-S interface, but also offers an approach to further enhance the performance of L-S TENG, which can promote the TENG applications in the field of microfluidic systems, liquid energy harvesting, and droplet sensory.
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Affiliation(s)
- Xinglin Tao
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Jinhui Nie
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Shuyao Li
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Yuxiang Shi
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Shiquan Lin
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Xiangyu Chen
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
| | - Zhong Lin Wang
- CAS Center for Excellence in Nanoscience, Beijing Key Laboratory of Micro-nano Energy and Sensor, Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083, P.R. China
- College of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing 100049, P.R. China
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245, United States
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25
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Pelimanni E, Hautala L, Hans A, Kivimäki A, Kook M, Küstner-Wetekam C, Marder L, Patanen M, Huttula M. Core and Valence Level Photoelectron Spectroscopy of Nanosolvated KCl. J Phys Chem A 2021; 125:4750-4759. [PMID: 34034483 PMCID: PMC8279652 DOI: 10.1021/acs.jpca.1c01539] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/22/2021] [Indexed: 01/04/2023]
Abstract
The solvation of alkali and halide ions in the aqueous environment has been a subject of intense experimental and theoretical research with multidisciplinary interests; yet, a comprehensive molecular-level understanding has still not been obtained. In recent years, electron spectroscopy has been increasingly applied to study the electronic and structural properties of aqueous ions with implications, especially in atmospheric chemistry. In this work, we report core and valence level (Cl 2p, Cl 3p, and K 3p) photoelectron spectra of the common alkali halide, KCl, doped in gas-phase water clusters in the size range of a few hundred water molecules. The results indicate that the electronic structure of these nanosolutions shows a distinct character from that observed at the liquid-vapor interface in liquid microjets and ambient pressure setups. Insights are provided into the unique solvation properties of ions in a nanoaqueous environment, emerging properties of bulk electrolyte solutions with growing cluster size, and sensitivity of the electronic structure to varying solvation configurations.
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Affiliation(s)
- Eetu Pelimanni
- Nano
and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
| | - Lauri Hautala
- Nano
and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
| | - Andreas Hans
- Nano
and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
- Universität
Kassel, Institut für Physik und CINSaT, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Antti Kivimäki
- Nano
and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
- MAX
IV Laboratory, Lund University, P.O. Box 118, SE-22100 Lund, Sweden
| | - Mati Kook
- Institute
of Physics, University of Tartu, W. Ostwaldi 1, EE-50411 Tartu, Estonia
| | - Catmarna Küstner-Wetekam
- Universität
Kassel, Institut für Physik und CINSaT, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Lutz Marder
- Universität
Kassel, Institut für Physik und CINSaT, Heinrich-Plett-Straße 40, 34132 Kassel, Germany
| | - Minna Patanen
- Nano
and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
| | - Marko Huttula
- Nano
and Molecular Systems Research Unit, Faculty of Science, University of Oulu, P.O. Box 3000, FI-90014 Oulu, Finland
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Thürmer S, Shinno T, Suzuki T. Valence Photoelectron Spectra of Liquid Methanol and Ethanol Measured Using He II Radiation. J Phys Chem A 2021; 125:2492-2503. [PMID: 33755491 DOI: 10.1021/acs.jpca.1c00288] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
High-resolution photoelectron (PE) spectra of liquid methanol and ethanol were measured using a liquid microjet and He IIα radiation (40.813 eV). The vertical ionization energy and the ionization threshold were determined as 9.70 ± 0.07 and 8.69 ± 0.07 eV for methanol and 9.52 ± 0.07 and 8.52 ± 0.07 eV for ethanol, respectively. Individual photoemission bands observed for the liquids are well correlated with those in PE spectra of the gaseous samples also measured in the present study, except that the liquid band positions were shifted on average by -1.23 eV for methanol and -1.10 eV for ethanol as compared to the gas. The 5a' and 7a' bands of liquid methanol exhibit specifically larger broadening than other bands, for which we attempted spectral fitting with two components, similarly with the case of the 3a1 band of liquid water. PE spectra of both liquid and gaseous ethanol are congested partly due to the presence of the trans and gauche isomers; however, the overall band positions are generally in good agreement with predictions based on quantum chemical calculations. Comparison of the measured PE spectra with experimental and simulated X-ray emission spectra indicate that spectral differences in the lowest ionization band of both methanol and ethanol originate from involvement of nuclear dynamics in the X-ray emission process.
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Affiliation(s)
- Stephan Thürmer
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto 606-8501, Japan
| | - Takatoshi Shinno
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto 606-8501, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo, Kyoto 606-8501, Japan
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Perry C, Jordan I, Zhang P, von Conta A, Nunes FB, Wörner HJ. Photoelectron Spectroscopy of Liquid Water with Tunable Extreme-Ultraviolet Radiation: Effects of Electron Scattering. J Phys Chem Lett 2021; 12:2990-2996. [PMID: 33733779 PMCID: PMC8006141 DOI: 10.1021/acs.jpclett.0c03424] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We report the first systematic photoelectron measurements of the three outer-valence bands of liquid water as a function of the ionizing photon energy in the near-threshold region. We use extreme-ultraviolet (XUV) radiation tunable between ∼17.1 and 35.6 eV, obtained through monochromatization of a high-harmonic source. We show that the absolute values of the apparent vertical ionization energies and their respective peak widths show a decreasing trend of their magnitudes with increasing photon energy close to the ionization threshold. We find that the observed effects do not only depend on the electron kinetic energy but are also different for the various outer-valence bands. These observations are consistent with, but not fully explained by, the effects of inelastic electron scattering.
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28
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Herbert JM. Dielectric continuum methods for quantum chemistry. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2021. [DOI: 10.1002/wcms.1519] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- John M. Herbert
- Department of Chemistry and Biochemistry The Ohio State University Columbus Ohio USA
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29
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Malerz S, Trinter F, Hergenhahn U, Ghrist A, Ali H, Nicolas C, Saak CM, Richter C, Hartweg S, Nahon L, Lee C, Goy C, Neumark DM, Meijer G, Wilkinson I, Winter B, Thürmer S. Low-energy constraints on photoelectron spectra measured from liquid water and aqueous solutions. Phys Chem Chem Phys 2021; 23:8246-8260. [PMID: 33710216 DOI: 10.1039/d1cp00430a] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on the effects of electron collision and indirect ionization processes, occurring at photoexcitation and electron kinetic energies well below 30 eV, on the photoemission spectra of liquid water. We show that the nascent photoelectron spectrum and, hence, the inferred electron binding energy can only be accurately determined if electron energies are large enough that cross sections for quasi-elastic scattering processes, such as vibrational excitation, are negligible. Otherwise, quasi-elastic scattering leads to strong, down-to-few-meV kinetic energy scattering losses from the direct photoelectron features, which manifest in severely distorted intrinsic photoelectron peak shapes. The associated cross-over point from predominant (known) electronically inelastic to quasi-elastic scattering seems to arise at surprisingly large electron kinetic energies, of approximately 10-14 eV. Concomitantly, we present evidence for the onset of indirect, autoionization phenomena (occurring via superexcited states) within a few eV of the primary and secondary ionization thresholds. These processes are inferred to compete with the direct ionization channels and primarily produce low-energy photoelectrons at photon and electron impact excitation energies below ∼15 eV. Our results highlight that vibrational inelastic electron scattering processes and neutral photoexcitation and autoionization channels become increasingly important when photon and electron kinetic energies are decreased towards the ionization threshold. Correspondingly, we show that for neat water and aqueous solutions, great care must be taken when quantitatively analyzing photoelectron spectra measured too close to the ionization threshold. Such care is essential for the accurate determination of solvent and solute ionization energies as well as photoelectron branching ratios and peak magnitudes.
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Affiliation(s)
- Sebastian Malerz
- Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.
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George MAR, Buttenberg F, Förstel M, Dopfer O. Microhydration of substituted diamondoid radical cations of biological relevance: infrared spectra of amantadine +-(H 2O) n = 1-3 clusters. Phys Chem Chem Phys 2020; 22:28123-28139. [PMID: 33290468 DOI: 10.1039/d0cp05299j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hydration of biomolecules and pharmaceutical compounds has a strong impact on their structure, reactivity, and function. Herein, we explore the microhydration structure around the radical cation of the widespread pharmaceutical drug amantadine (C16H15NH2, Ama) by infrared photodissociation (IRPD) spectroscopy of mass-selected Ama+Wn = 1-3 clusters (W = H2O) recorded in the NH, CH, and OH stretch range of the cation ground electronic state. Analysis of the size-dependent frequency shifts by dispersion-corrected density functional theory calculations (B3LYP-D3/cc-pVTZ) provides detailed information about the acidity of the protons of the NH2 group of Ama+ and the structure and strength of the NHO and OHO hydrogen bonds (H-bonds) of the hydration network. The preferred sequential cluster growth begins with hydration of the two acidic NH protons of the NH2 group (n = 1-2) and continues with an extension of the H-bonded hydration network by forming an OHO H-bond of the third W to one ligand in the first hydration subshell (n = 3), like in the W2 dimer. For n = 2, a minor population corresponds to Ama+W2 structures with a W2 unit attached to Ama+via a NHW2 H-bond. Although the N-H proton donor bonds are progressively destabilized by gradual microhydration, no proton transfer to the Wn solvent cluster is observed in the investigated size range (n ≤ 3). Besides the microhydration structure, we also obtain a first impression of the structure and IR spectrum of bare Ama+, as well as the effects of both ionization and hydration on the structure of the adamantyl cage. Comparison of Ama+ with aliphatic and aromatic primary amine radical cations reveals differences in the acidity of the NH2 group and the resulting interaction with W caused by substitution of the cycloalkyl cage.
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von Szentpály L, Kaya S, Karakuş N. Why and When Is Electrophilicity Minimized? New Theorems and Guiding Rules. J Phys Chem A 2020; 124:10897-10908. [DOI: 10.1021/acs.jpca.0c08196] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- László von Szentpály
- Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Savaş Kaya
- Department of Pharmacy, Health Services Vocational School, Sivas Cumhuriyet University, 58140 Sivas, Turkey
| | - Nihat Karakuş
- Department of Chemistry, Faculty of Science, Sivas Cumhuriyet University, 58140 Sivas, Turkey
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Nishitani J, Karashima S, West CW, Suzuki T. Surface potential of liquid microjet investigated using extreme ultraviolet photoelectron spectroscopy. J Chem Phys 2020; 152:144503. [PMID: 32295374 DOI: 10.1063/5.0005930] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Photoelectron spectroscopy of a liquid microjet requires careful energy calibration against electrokinetic charging of the microjet. For minimizing the error from this calibration procedure, Kurahashi et al. previously suggested optimization of an electrolyte concentration in aqueous solutions [Kurahashi et al., J. Chem. Phys. 140, 174506 (2014)]. More recently, Olivieri et al. proposed an alternative method of applying a variable external voltage on the liquid microjet [Olivieri et al., Phys. Chem. Chem. Phys. 18, 29506 (2016)]. In this study, we examined these two methods of calibration using extreme ultraviolet photoelectron spectroscopy with a magnetic bottle time-of-flight photoelectron spectrometer. We confirmed that the latter method flattens the vacuum level potential around the microjet, similar to the former method, while we found that the applied voltage energy-shifts the entire spectrum. Thus, careful energy recalibration is indispensable after the application of an external voltage for accurate measurements. It is also pointed out that electric conductivity of liquid on the order of 1 mS/cm is required for stable application of an external voltage. Therefore, both methods need a similar concentration of an electrolyte. Using the calibration method proposed by Olivieri et al., Perry et al. have recently revised the vertical ionization energy of liquid water to be 11.67(15) eV [Perry et al., J. Phys. Chem. Lett. 11, 1789 (2020)], which is 0.4 eV higher than the previously estimated value. While the source of this discrepancy is still unclear, we estimate that their calibration method possibly leaves uncertainty on the order of 0.1 eV.
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Affiliation(s)
- Junichi Nishitani
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Shutaro Karashima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Christopher W West
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
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