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Schnorr K, Belina M, Augustin S, Lindenblatt H, Liu Y, Meister S, Pfeifer T, Schmid G, Treusch R, Trost F, Slavíˇek P, Moshammer R. Direct tracking of ultrafast proton transfer in water dimers. SCIENCE ADVANCES 2023; 9:eadg7864. [PMID: 37436977 PMCID: PMC10337913 DOI: 10.1126/sciadv.adg7864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/08/2023] [Indexed: 07/14/2023]
Abstract
Upon ionization, water forms a highly acidic radical cation H2O+· that undergoes ultrafast proton transfer (PT)-a pivotal step in water radiation chemistry, initiating the production of reactive H3O+, OH[Formula: see text] radicals, and a (hydrated) electron. Until recently, the time scales, mechanisms, and state-dependent reactivity of ultrafast PT could not be directly traced. Here, we investigate PT in water dimers using time-resolved ion coincidence spectroscopy applying a free-electron laser. An extreme ultraviolet (XUV) pump photon initiates PT, and only dimers that have undergone PT at the instance of the ionizing XUV probe photon result in distinct H3O+ + OH+ pairs. By tracking the delay-dependent yield and kinetic energy release of these ion pairs, we measure a PT time of (55 ± 20) femtoseconds and image the geometrical rearrangement of the dimer cations during and after PT. Our direct measurement shows good agreement with nonadiabatic dynamics simulations for the initial PT and allows us to benchmark nonadiabatic theory.
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Affiliation(s)
- Kirsten Schnorr
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
- Paul Scherrer Institut, Forschungsstrasse 111, 5232 Villigen, Switzerland
| | - Michal Belina
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, 16628 Prague 6, Czech Republic
| | - Sven Augustin
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
- Paul Scherrer Institut, Forschungsstrasse 111, 5232 Villigen, Switzerland
| | - Hannes Lindenblatt
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Yifan Liu
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Severin Meister
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Thomas Pfeifer
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Georg Schmid
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Rolf Treusch
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Florian Trost
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
| | - Petr Slavíˇek
- Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, 16628 Prague 6, Czech Republic
| | - Robert Moshammer
- Max Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg, Germany
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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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Abstract
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Cluster-size-resolved
ultrafast dynamics of the solvated electron
in neutral water clusters with n = 3 to ∼200
molecules are studied with pump–probe time-of-flight mass spectrometry
after below band gap excitation. For the smallest clusters, no longer-lived
(>100–200 fs) hydrated electrons were detected, indicating
a minimum size of n ∼ 14 for being able to
sustain hydrated electrons. Larger clusters show a systematic increase
of the number of hydrated electrons per molecule on the femtosecond
to picosecond time scale. We propose that with increasing cluster
size the underlying dynamics is governed by more effective electron
formation processes combined with less effective electron loss processes,
such as ultrafast hydrogen ejection and recombination. It appears
unlikely that any size dependence of the solvent relaxation dynamics
would be reflected in the observed time-resolved ion yields.
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Affiliation(s)
- Loren Ban
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
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Yamamoto YI, Suzuki T. Ultrafast Dynamics of Water Radiolysis: Hydrated Electron Formation, Solvation, Recombination, and Scavenging. J Phys Chem Lett 2020; 11:5510-5516. [PMID: 32551690 DOI: 10.1021/acs.jpclett.0c01468] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The ultrafast formation, solvation, and geminate recombination of hydrated electrons upon vacuum ultraviolet photoexcitation of liquid water and the static and dynamic scavenging by NO3- are investigated using femtosecond time-resolved photoelectron spectroscopy. The solvation time constant for excess electrons is typical of that for liquid water but increases slightly with increasing excitation energy. The electron survival probability for geminate recombination is found to be much lower than the literature values owing to previously unobserved ultrafast geminate recombination in a period of 5 ps. NO3- induces the ultrafast (static) scavenging of photoexcited electronic states of liquid water and the dynamic scavenging of detached electrons with a reaction rate that is dependent on the excitation energy. The formation of hydrated electrons at 7.7 eV is ascribed to a H-atom-transfer process, but it is plausible that additional formation channels open at higher energies.
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Affiliation(s)
- Yo-Ichi Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
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5
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Stetina TF, Sun S, Lingerfelt DB, Clark A, Li X. The Role of Excited-State Proton Relays in the Photochemical Dynamics of Water Nanodroplets. J Phys Chem Lett 2019; 10:3694-3698. [PMID: 31091108 DOI: 10.1021/acs.jpclett.9b01062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work, we applied nonadiabatic excited-state molecular dynamics in tandem with ab initio electronic structure theory to illustrate a complete mechanistic landscape underpinning the ultraviolet absorption-initiated photochemical dynamics in water nanodroplets. The goal is to understand the nonequilibrium excited-state molecular dynamics initiated by the relaxation of a solvated photoelectron and consequential photochemical processes. The lowest-lying excited state shows the proton dissociation for a single water molecule forming intermediate hydronium complexes through a proton relay. At approximately 100 fs, the proton relay process gives rise to the relaxation of the excited state accompanied by a rapid increase in the nonadiabatic coupling strength with the ground state, and the nanodroplet nonradiatively decays. The nonadiabatic transition to the ground state produces excited vibrational states that facilitate the recombination of the dissociated proton and hydroxyl group, eventually leading to the desorption of water molecules from the nanodroplet. Additionally, lifetimes of transient photochemical events are also resolved for the relaxation of a solvated electron, excited-state proton relay, and nonradiative transition.
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Affiliation(s)
- Torin F Stetina
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - Shichao Sun
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
| | - David B Lingerfelt
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Aurora Clark
- Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States
- Pacific Northwest National Laboratory , Richland , Washington 99352 , United States
| | - Xiaosong Li
- Department of Chemistry , University of Washington , Seattle , Washington 98195 , United States
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6
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Tachikawa H, Takada T. Ionization dynamics of the branched water cluster: A long-lived non-proton-transferred intermediate. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2016.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
A proton transfer process is usually dominant in several biological phenomena such as the energy relaxation of photo-excited DNA base pairs and a charge relay process in Ser-His-Glu.
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Affiliation(s)
- Hiroto Tachikawa
- Division of Materials Chemistry
- Graduate School of Engineering
- Hokkaido University
- Sapporo 060-8628
- Japan
| | - Tomoya Takada
- Department of Material Chemistry
- Asahikawa National College of Technology
- Asahikawa 071-8142
- Japan
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Affiliation(s)
- Hainam Do
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
| | - Nicholas A. Besley
- School of Chemistry, University of Nottingham, University Park, Nottingham,
NG7 2RD, U.K
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10
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Ghotbi M, Trabs P, Beutler M, Noack F. Generation of tunable sub-45 femtosecond pulses by noncollinear four-wave mixing. OPTICS LETTERS 2013; 38:486-488. [PMID: 23455111 DOI: 10.1364/ol.38.000486] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Generation of sub-45 fs vacuum UV (VUV) pulses tunable across the spectral range of 146-151 nm at 1 kHz repetition rate is reported. The pulses are produced using noncollinear difference-frequency four-wave mixing between the third-harmonic of an amplified Ti:sapphire laser and the signal wavelength of an infrared optical parametric amplifier (ω(VUV)=2ω(TH)-ω(IR)) in krypton and argon. The generated VUV pulses have energies as high as 90 nJ. Pulse duration measurements are realized by cross correlation between the VUV pulses and the laser fundamental wavelength using pump-probe ionization in xenon.
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Affiliation(s)
- Masood Ghotbi
- Max-Born-Institute for Nonlinear Optics and Ultrafast Spectroscopy, 2A Max-Born-Strasse, Berlin D-12489, Germany
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Acocella A, Jones GA, Zerbetto F. Excitation Energy Transfer and Low-Efficiency Photolytic Splitting of Water Ice by Vacuum UV Light. J Phys Chem Lett 2012; 3:3610-3615. [PMID: 26290996 DOI: 10.1021/jz301640h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Experimental estimates of photolytic efficiency (yield per photon) for photodissociation and photodesorption from water ice range from about 10(-3) to 10(-1). However, in the case of photodissociation of water in the gas phase, it is close to unity. Exciton dynamics carried out by a quantum mechanical time-dependent propagator shows that in the eight most stable water hexamers, the excitation diffuses away from the initially excited molecule within a few femtoseconds. On the basis of these quantum dynamics simulations, it is hypothesized that the ultrafast exciton energy transfer process, which in general gives rise to a delocalized exciton within these clusters, may contribute to the low efficiency of photolytic processes in water ice. It is proposed that exciton diffusion inherently competes with the nuclear dynamics that drives the photodissociation process in the repulsive S1 state on the sub-10 fs time scale.
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Affiliation(s)
- Angela Acocella
- †Dipartimento di Chimica "G. Ciamician", Università di Bologna, V. F. Selmi 2, 40126 Bologna, Italy
| | - Garth A Jones
- ‡School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Francesco Zerbetto
- †Dipartimento di Chimica "G. Ciamician", Università di Bologna, V. F. Selmi 2, 40126 Bologna, Italy
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Buchner F, Ritze HH, Beutler M, Schultz T, Hertel IV, Lübcke A. Role of alkali cations for the excited state dynamics of liquid water near the surface. J Chem Phys 2012; 137:024503. [DOI: 10.1063/1.4732582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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13
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Golan A, Ahmed M. Ionization of Water Clusters Mediated by Exciton Energy Transfer from Argon Clusters. J Phys Chem Lett 2012; 3:458-462. [PMID: 26286046 DOI: 10.1021/jz2016654] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The exciton energy deposited in an argon cluster (Arn, ⟨n = 20⟩) using VUV radiation is transferred to softly ionize doped water clusters ((H2O)n, n = 1-9), leading to the formation of nonfragmented clusters. Following the initial excitation, electronic energy is channeled to ionize the doped water cluster while evaporating the Ar shell, allowing identification of fragmented and complete water cluster ions. Examination of the photoionization efficiency curve shows that cluster evaporation from excitons located above 12.6 eV is not enough to cool the energized water cluster ion and leads to their dissociation to (H2O)n-2H(+) (protonated) clusters.
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Affiliation(s)
- Amir Golan
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Musahid Ahmed
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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14
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Cabanillas-Vidosa I, Rossa M, Pino GA, Ferrero JC. Unexpected size distribution of Ba(H2O)n clusters: why is the intensity of the Ba(H2O)1 cluster anomalously low? Phys Chem Chem Phys 2011; 13:13387-94. [PMID: 21701713 DOI: 10.1039/c0cp02881a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An experimental and theoretical study on the reactivity of neutral Ba atoms with water clusters has been conducted to unravel the origin of the irregular intensity pattern observed in one-photon ionization mass spectra of a Ba(H(2)O)(n)/BaOH(H(2)O)(n-1) (n = 1-4) cluster distribution, which was generated in a laser vaporization-supersonic expansion source. The most remarkable irregular feature is the finding for n = 1 of a lower intensity for the Ba(+)(H(2)O)(n) peak with respect to that of BaOH(+)(H(2)O)(n-1), which is opposite to the trend for n = 2-4. Rationalization of the data required consideration of a distinct behavior of ground-state and electronically excited state Ba atoms in inelastic and reactive Ba + (H(2)O)(n) encounters that can occur in the cluster source. Within this picture, the generation of Ba(H(2)O)(n) (n > 1) association products results from stabilizing collisions with atoms of the carrier gas, which are favored by intramolecular vibrational redistribution that operates on the corresponding collision intermediates prior to stabilization; the latter is unlikely to occur for Ba + (H(2)O) encounters. Overall, this interpretation is consistent with additional in-source laser excitation and quenching experiments, which aimed to explore qualitatively the effect of perturbing the Ba atom electronic state population distribution on the observed intensity pattern, as well as with the energetics of various possible reactions for the Ba + H(2)O system that derive from high level ab initio calculations.
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Affiliation(s)
- Iván Cabanillas-Vidosa
- Centro Láser de Ciencias Moleculares, INFIQC and Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000IUS Córdoba, Argentina
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