1
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Turi L, Baranyi B, Madarász Á. 2-in-1 Phase Space Sampling for Calculating the Absorption Spectrum of the Hydrated Electron. J Chem Theory Comput 2024; 20:4265-4277. [PMID: 38727675 PMCID: PMC11137824 DOI: 10.1021/acs.jctc.4c00106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/29/2024]
Abstract
The investigation of vibrational effects on absorption spectrum calculations often employs Wigner sampling or thermal sampling. While Wigner sampling incorporates zero-point energy, it may not be suitable for flexible systems. Thermal sampling is applicable to anharmonic systems yet treats nuclei classically. The application of generalized smoothed trajectory analysis (GSTA) as a postprocessing method allows for the incorporation of nuclear quantum effects (NQEs), combining the advantages of both sampling methods. We demonstrate this approach in computing the absorption spectrum of a hydrated electron. Theoretical exploration of the hydrated electron and its embryonic forms, such as water cluster anions, poses a significant challenge due to the diffusivity of the excess electron and the continuous motion of water molecules. In many previous studies, the wave nature of atomic nuclei is often neglected, despite the substantial impact of NQEs on thermodynamic and spectroscopic properties, particularly for hydrogen atoms. In our studies, we examine these NQEs for the excess electrons in various water systems. We obtained structures from mixed classical-quantum simulations for water cluster anions and the hydrated electron by incorporating the quantum effects of atomic nuclei with the filtration of the classical trajectories. Absorption spectra were determined at different theoretical levels. Our results indicate significant NQEs, red shift, and broadening of the spectra for hydrated electron systems. This study demonstrates the applicability of GSTA to complex systems, providing insights into NQEs on energetic and structural properties.
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Affiliation(s)
- László Turi
- Institute
of Chemistry, ELTE, Eötvös
Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Bence Baranyi
- Institute
of Chemistry, ELTE, Eötvös
Loránd University, Pázmány Péter sétány 1/A, Budapest H-1117, Hungary
| | - Ádám Madarász
- Research
Centre for Natural Sciences, Magyar Tudósok Körútja 2, H-1117 Budapest, Hungary
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2
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Jordan CJC, Coons MP, Herbert JM, Verlet JRR. Spectroscopy and dynamics of the hydrated electron at the water/air interface. Nat Commun 2024; 15:182. [PMID: 38167300 PMCID: PMC10762076 DOI: 10.1038/s41467-023-44441-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024] Open
Abstract
The hydrated electron, e-(aq), has attracted much attention as a central species in radiation chemistry. However, much less is known about e-(aq) at the water/air surface, despite its fundamental role in electron transfer processes at interfaces. Using time-resolved electronic sum-frequency generation spectroscopy, the electronic spectrum of e-(aq) at the water/air interface and its dynamics are measured here, following photo-oxidation of the phenoxide anion. The spectral maximum agrees with that for bulk e-(aq) and shows that the orbital density resides predominantly within the aqueous phase, in agreement with supporting calculations. In contrast, the chemistry of the interfacial hydrated electron differs from that in bulk water, with e-(aq) diffusing into the bulk and leaving the phenoxyl radical at the surface. Our work resolves long-standing questions about e-(aq) at the water/air interface and highlights its potential role in chemistry at the ubiquitous aqueous interface.
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Affiliation(s)
| | - Marc P Coons
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - John M Herbert
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA.
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham, DH1 4LJ, UK.
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3
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Gao XF, Hood DJ, Zhao X, Nathanson GM. Creation and Reaction of Solvated Electrons at and near the Surface of Water. J Am Chem Soc 2023; 145:10987-10990. [PMID: 37191478 DOI: 10.1021/jacs.3c03370] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Solvated electrons (es-) are among nature's most powerful reactants, with over 2600 reactions investigated in bulk water. These electrons can also be created at and near the surface of water by exposing an aqueous microjet in vacuum to gas-phase sodium atoms, which ionize into es- and Na+ within the top few layers. When a reactive surfactant is added to the jet, the surfactant and es- become coreactants localized in the interfacial region. We report the reaction of es- with the surfactant benzyltrimethylammonium in a 6.7 M LiBr/water microjet at 235 K and pH = 2. The reaction intermediates trimethylamine (TMA) and benzyl radical are identified by mass spectrometry after they evaporate from solution into the gas phase. Their detection demonstrates that TMA can escape before it is protonated and benzyl before it combines with itself or a H atom. Diffusion-reaction calculations indicate that es- reacts on average within 20 Å of the surface and perhaps within the surfactant monolayer itself, while unprotonated TMA evaporates from the top 40 Å. The escape depth exceeds 1300 Å for the more slowly reacting benzyl radical. These proof-of-principle experiments establish an approach for exploring the near-interfacial analogues of aqueous bulk-phase radical chemistry through the evaporation of reaction intermediates into the gas phase.
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Affiliation(s)
- Xiao-Fei Gao
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - David J Hood
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Xianyuan Zhao
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Gilbert M Nathanson
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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4
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Jordan CJC, Lowe EA, Verlet JRR. Photooxidation of the Phenolate Anion is Accelerated at the Water/Air Interface. J Am Chem Soc 2022; 144:14012-14015. [PMID: 35900260 PMCID: PMC9376918 DOI: 10.1021/jacs.2c04935] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
![]()
Molecular photodynamics can be dramatically affected
at the water/air
interface. Probing such dynamics is challenging, with product formation
often probed indirectly through its interaction with interfacial water
molecules using time-resolved and phase-sensitive vibrational sum-frequency
generation (SFG). Here, the photoproduct formation of the phenolate
anion at the water/air interface is probed directly using time-resolved
electronic SFG and compared to transient absorption spectra in bulk
water. The mechanisms are broadly similar, but 2 to 4 times faster
at the surface. An additional decay is observed at the surface which
can be assigned to either diffusion of hydrated electrons from the
surface into the bulk or due to increased geminate recombination at
the surface. These overall results are in stark contrast to phenol,
where dynamics were observed to be 104 times faster and
for which the hydrated electron was also a photoproduct. Our attempt
to probe phenol showed no electron signal at the interface.
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Affiliation(s)
- Caleb J C Jordan
- Department of Chemistry, Durham University, Durham, DH1 3LE, United Kingdom
| | - Eleanor A Lowe
- Department of Chemistry, Durham University, Durham, DH1 3LE, United Kingdom
| | - Jan R R Verlet
- Department of Chemistry, Durham University, Durham, DH1 3LE, United Kingdom
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5
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James Wood R, Sidnell T, Ross I, McDonough J, Lee J, Bussemaker MJ. Ultrasonic degradation of perfluorooctane sulfonic acid (PFOS) correlated with sonochemical and sonoluminescence characterisation. ULTRASONICS SONOCHEMISTRY 2020; 68:105196. [PMID: 32593965 DOI: 10.1016/j.ultsonch.2020.105196] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 05/27/2023]
Abstract
Sonolysis has been proposed as a promising treatment technology to remove per- and polyfluoroalkyl substances (PFASs) from contaminated water. The mechanism of degradation is generally accepted to be high temperature pyrolysis at the bubble surface with dependency upon surface reaction site availability. However, the parametric effects of the ultrasonic system on PFAS degradation are poorly understood, making upscale challenging and leading to less than optimal use of ultrasonic energy. Hence, a thorough understanding of these parametric effects could lead to improved efficiency and commercial viability. Here, reactor characterisation was performed at 44, 400, 500, and 1000 kHz using potassium iodide (KI) dosimetry, sonochemiluminescence (SCL), and sonoluminescence (SL) in water and a solution of potassium salt of PFOS (hereafter, K-PFOS). Then the degradation of K-PFOS (10 mg L-1 in 200 mL solution) was investigated at these four frequencies. At 44 kHz, no PFOS degradation was observed. At 400, 500, and 1000 kHz the amount of degradation was 96.9, 93.8, and 91.2%, respectively, over four hours and was accompanied by stoichiometric fluoride release, indicating mineralisation of the PFOS molecule. Close correlation of PFOS degradation trends with KI dosimetry and SCL intensity was observed, which suggested degradation occurred under similar conditions to these sonochemical processes. At 1000 kHz, where the overall intensity of collapse was significantly reduced (measured by SL), PFOS degradation was not similarly decreased. Discussion is presented that suggests a hydrated electron degradation mechanism for PFOS may occur in ultrasonic conditions. This mechanism is a novel hypothesis in the field of PFAS sonolysis.
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Affiliation(s)
- Richard James Wood
- Department of Chemical and Process Engineering, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| | - Tim Sidnell
- Department of Chemical and Process Engineering, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| | - Ian Ross
- ARCADIS, Global Remediation, 10th Floor, 3 Piccadilly Place, Manchester, Greater Manchester M1 3BN, United Kingdom
| | - Jeffrey McDonough
- ARCADIS US 630 Plaza Drive Suite 200 Highlands Ranch, CO 80129, United States
| | - Judy Lee
- Department of Chemical and Process Engineering, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| | - Madeleine J Bussemaker
- Department of Chemical and Process Engineering, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom.
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6
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Glover WJ, Schwartz BJ. The Fluxional Nature of the Hydrated Electron: Energy and Entropy Contributions to Aqueous Electron Free Energies. J Chem Theory Comput 2020; 16:1263-1270. [PMID: 31914315 DOI: 10.1021/acs.jctc.9b00496] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
There has been a great deal of recent controversy over the structure of the hydrated electron and whether it occupies a cavity or contains a significant number of interior waters (noncavity). The questions we address in this work are, from a free energy perspective, how different are these proposed structures? Do the different structures all lie along a single continuum, or are there significant differences (i.e., free energy barriers) between them? To address these questions, we have performed a series of one-electron calculations using umbrella sampling with quantum biased molecular dynamics along a coordinate that directly reflects the number of water molecules in the hydrated electron's interior. We verify that a standard cavity model of the hydrated electron behaves essentially as a hard sphere: the model is dominated by repulsion at short range such that water is expelled from a local volume around the electron, leading to a water solvation shell like that of a pseudohalide ion. The repulsion is much larger than thermal energies near room temperature, explaining why such models exhibit properties with little temperature dependence. On the other hand, our calculations reveal that a noncavity model is highly fluxional, meaning that thermal motions cause the number of interior waters to fluctuate from effectively zero (i.e., a cavity-type electron) to potentially above the bulk water density. The energetic contributions in the noncavity model are still repulsive in the sense that they favor cavity formation, so the fluctuations in structure are driven largely by entropy: the entropic cost for expelling water from a region of space is large enough that some water is still driven into the electron's interior. As the temperature is lowered and entropy becomes less important, the noncavity electron's structure is predicted to become more cavity-like, consistent with the observed temperature dependence of the hydrated electron's properties. Thus, we argue that although the specific noncavity model we study overestimates the preponderance of fluctuations involving interior water molecules, with appropriate refinements to correctly capture the true average number of interior waters and molar solvation volume, a fluxional model likely makes the most sense for understanding the various experimental properties of the hydrated electron.
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Affiliation(s)
- William J Glover
- NYU Shanghai , 1555 Century Ave. , Pudong, Shanghai , China 200122.,NYU-ECNU Center for Computational Chemistry at NYU Shanghai , 3663 Zhongshang Road , Shanghai , China 200062.,Department of Chemistry , New York University , New York , New York 10003 , United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry , University of California, Los Angeles , 607 Charles E. Young Drive East , Los Angeles , California 90095-1569 , United States
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7
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Structure and spectrum of the hydrated electron. A combined quantum chemical statistical mechanical simulation. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Dasgupta S, Rana B, Herbert JM. Ab Initio Investigation of the Resonance Raman Spectrum of the Hydrated Electron. J Phys Chem B 2019; 123:8074-8085. [PMID: 31442044 DOI: 10.1021/acs.jpcb.9b04895] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
According to the conventional picture, the aqueous or "hydrated" electron, e-(aq), occupies an excluded volume (cavity) in the structure of liquid water. However, simulations with certain one-electron models predict a more delocalized spin density for the unpaired electron, with no distinct cavity structure. It has been suggested that only the latter (non-cavity) structure can explain the hydrated electron's resonance Raman spectrum, although this suggestion is based on calculations using empirical frequency maps developed for neat liquid water, not for e-(aq). All-electron ab initio calculations presented here demonstrate that both cavity and non-cavity models of e-(aq) afford significant red-shifts in the O-H stretching region. This effect is nonspecific and arises due to electron penetration into frontier orbitals of the water molecules. Only the conventional cavity model, however, reproduces the splitting of the H-O-D bend (in isotopically mixed water) that is observed experimentally and arises due to the asymmetric environments of the hydroxyl moieties in the electron's first solvation shell. We conclude that the cavity model of e-(aq) is more consistent with the measured resonance Raman spectrum than is the delocalized, non-cavity model, despite previous suggestions to the contrary. Furthermore, calculations with hybrid density functionals and with Hartree-Fock theory predict that non-cavity liquid geometries afford only unbound (continuum) states for an extra electron, whereas in reality this energy level should lie more than 3 eV below vacuum level. As such, the non-cavity model of e-(aq) appears to be inconsistent with available vibrational spectroscopy, photoelectron spectroscopy, and quantum chemistry.
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Affiliation(s)
- Saswata Dasgupta
- Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States
| | - Bhaskar Rana
- 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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9
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Abstract
Electron attachment onto water clusters to form water cluster anions is studied by varying the point of electron attachment along a molecular beam axis and probing the produced cluster anions using photoelectron spectroscopy. The results show that the point of electron attachment has a clear effect on the final distribution of isomers for a cluster containing 78 water molecules, with isomer I formed preferentially near the start of the expansion and isomer II formed preferentially once the molecular beam has progressed for several millimeters. These changes can be accounted for by the cluster growth rate along the beam. Near the start of the expansion, cluster growth is proceeding rapidly with condensing water molecules solvating the electron, while further along the expansion, the growth has terminated and electrons are attached to large and cold preformed clusters, leading to the isomer associated with a loosely bound surface state.
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Affiliation(s)
- Aude Lietard
- Department of Chemistry , Durham University , Durham DH1 3LE , United Kingdom
| | - Jan R R Verlet
- Department of Chemistry , Durham University , Durham DH1 3LE , United Kingdom
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10
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Abstract
A cavity or excluded-volume structure best explains the experimental properties of the aqueous or “hydrated” electron.
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Affiliation(s)
- John M. Herbert
- Department of Chemistry & Biochemistry
- The Ohio State University
- Columbus
- USA
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11
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Luckhaus D, Yamamoto YI, Suzuki T, Signorell R. Genuine binding energy of the hydrated electron. SCIENCE ADVANCES 2017; 3:e1603224. [PMID: 28508051 PMCID: PMC5409453 DOI: 10.1126/sciadv.1603224] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/02/2017] [Indexed: 05/24/2023]
Abstract
The unknown influence of inelastic and elastic scattering of slow electrons in water has made it difficult to clarify the role of the solvated electron in radiation chemistry and biology. We combine accurate scattering simulations with experimental photoemission spectroscopy of the hydrated electron in a liquid water microjet, with the aim of resolving ambiguities regarding the influence of electron scattering on binding energy spectra, photoelectron angular distributions, and probing depths. The scattering parameters used in the simulations are retrieved from independent photoemission experiments of water droplets. For the ground-state hydrated electron, we report genuine values devoid of scattering contributions for the vertical binding energy and the anisotropy parameter of 3.7 ± 0.1 eV and 0.6 ± 0.2, respectively. Our probing depths suggest that even vacuum ultraviolet probing is not particularly surface-selective. Our work demonstrates the importance of quantitative scattering simulations for a detailed analysis of key properties of the hydrated electron.
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Affiliation(s)
- David Luckhaus
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
| | - Yo-ichi Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Ruth Signorell
- Laboratory of Physical Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, CH-8093 Zürich, Switzerland
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12
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Glover WJ, Schwartz BJ. Short-Range Electron Correlation Stabilizes Noncavity Solvation of the Hydrated Electron. J Chem Theory Comput 2016; 12:5117-5131. [PMID: 27576177 DOI: 10.1021/acs.jctc.6b00472] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The hydrated electron, e-(aq), has often served as a model system to understand the influence of condensed-phase environments on electronic structure and dynamics. Despite over 50 years of study, however, the basic structure of e-(aq) is still the subject of controversy. In particular, the structure of e-(aq) was long assumed to be an electron localized within a solvent cavity, in a manner similar to halide solvation. Recently, however, we suggested that e-(aq) occupies a region of enhanced water density with little or no discernible cavity. The potential we developed was only subtly different from those that give rise to a cavity solvation motif, which suggests that the driving forces for noncavity solvation involve subtle electron-water attractive interactions at close distances. This leads to the question of how dispersion interactions are treated in simulations of the hydrated electron. Most dispersion potentials are ad hoc or are not designed to account for the type of close-contact electron-water overlap that might occur in the condensed phase, and where short-range dynamic electron correlation is important. To address this, in this paper we develop a procedure to calculate the potential energy surface between a single water molecule and an excess electron with high-level CCSD(T) electronic structure theory. By decomposing the electron-water potential into its constituent energetic contributions, we find that short-range electron correlation provides an attraction of comparable magnitude to the mean-field interactions between the electron and water. Furthermore, we find that by reoptimizing a popular cavity-forming one-electron model potential to better capture these attractive short-range interactions, the enhanced description of correlation predicts a noncavity e-(aq) with calculated properties in better agreement with experiment. Although much attention has been placed on the importance of long-range dispersion interactions in water cluster anions, our study reveals that largely unexplored short-range correlation effects are crucial in dictating the solvation structure of the condensed-phase hydrated electron.
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Affiliation(s)
- William J Glover
- NYU-ECNU Center for Computational Chemistry, New York University Shanghai , Shanghai, 200122, China.,Department of Chemistry, New York University , New York, New York 10003, United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095, United States
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13
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Coons MP, You ZQ, Herbert JM. The Hydrated Electron at the Surface of Neat Liquid Water Appears To Be Indistinguishable from the Bulk Species. J Am Chem Soc 2016; 138:10879-86. [DOI: 10.1021/jacs.6b06715] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marc P. Coons
- Department of Chemistry and
Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Zhi-Qiang You
- 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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14
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Casey JR, Schwartz BJ, Glover WJ. Free Energies of Cavity and Noncavity Hydrated Electrons Near the Instantaneous Air/Water Interface. J Phys Chem Lett 2016; 7:3192-3198. [PMID: 27479028 DOI: 10.1021/acs.jpclett.6b01150] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The properties of the hydrated electron at the air/water interface are computed for both a cavity and a noncavity model using mixed quantum/classical molecular dynamics simulation. We take advantage of our recently developed formalism for umbrella sampling with a restrained quantum expectation value to calculate free-energy profiles of the hydrated electron's position relative to the water surface. We show that it is critical to use an instantaneous description of the air/water interface rather than the Gibbs' dividing surface to obtain accurate potentials of mean force. We find that noncavity electrons, which prefer to encompass several water molecules, avoid the interface where water molecules are scarce. In contrast, cavity models of the hydrated electron, which prefer to expel water, have a local free-energy minimum near the interface. When the cavity electron occupies this minimum, its absorption spectrum is quite red-shifted, its binding energy is significantly lowered, and its dynamics speed up quite a bit compared with the bulk, features that have not been found by experiment. The surface activity of the electron therefore serves as a useful test of cavity versus noncavity electron solvation.
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Affiliation(s)
- Jennifer R Casey
- Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States
| | - Benjamin J Schwartz
- Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States
| | - William J Glover
- NYU-ECNU Center for Computational Chemistry, New York University Shanghai , Shanghai 200122, China
- Department of Chemistry, New York University , New York, New York 10003, United States
- Department of Chemistry, East China Normal University , Shanghai 200062, China
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15
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Partially Hydrated Electrons at the Air/Water Interface Observed by UV-Excited Time-Resolved Heterodyne-Detected Vibrational Sum Frequency Generation Spectroscopy. J Am Chem Soc 2016; 138:7551-7. [PMID: 27281547 DOI: 10.1021/jacs.6b02171] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrated electrons are the most fundamental anion species, consisting only of electrons and surrounding water molecules. Although hydrated electrons have been extensively studied in the bulk aqueous solutions, even their existence is still controversial at the water surface. Here, we report the observation and characterization of hydrated electrons at the air/water interface using new time-resolved interface-selective nonlinear vibrational spectroscopy. With the generation of electrons at the air/water interface by ultraviolet photoirradiation, we observed the appearance of a strong transient band in the OH stretch region by heterodyne-detected vibrational sum-frequency generation. Through the comparison with the time-resolved spectra at the air/indole solution interface, the transient band was assigned to the vibration of water molecules that solvate electrons at the interface. The analysis of the frequency and decay of the observed transient band indicated that the electrons are only partially hydrated at the water surface, and that they escape into the bulk within 100 ps.
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16
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Yamamoto YI, Karashima S, Adachi S, Suzuki T. Wavelength Dependence of UV Photoemission from Solvated Electrons in Bulk Water, Methanol, and Ethanol. J Phys Chem A 2016; 120:1153-9. [DOI: 10.1021/acs.jpca.5b09601] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yo-ichi Yamamoto
- 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
| | - Shunsuke Adachi
- 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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17
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The solvation of electrons by an atmospheric-pressure plasma. Nat Commun 2015; 6:7248. [PMID: 26088017 PMCID: PMC4557361 DOI: 10.1038/ncomms8248] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/20/2015] [Indexed: 11/25/2022] Open
Abstract
Solvated electrons are typically generated by radiolysis or photoionization of solutes. While plasmas containing free electrons have been brought into contact with liquids in studies dating back centuries, there has been little evidence that electrons are solvated by this approach. Here we report direct measurements of solvated electrons generated by an atmospheric-pressure plasma in contact with the surface of an aqueous solution. The electrons are measured by their optical absorbance using a total internal reflection geometry. The measured absorption spectrum is unexpectedly blue shifted, which is potentially due to the intense electric field in the interfacial Debye layer. We estimate an average penetration depth of 2.5±1.0 nm, indicating that the electrons fully solvate before reacting through second-order recombination. Reactions with various electron scavengers including H+, NO2−, NO3− and H2O2 show that the kinetics are similar, but not identical, to those for solvated electrons formed in bulk water by radiolysis. Free, or solvated, electrons in a solution are known to form at the interface between a liquid and a gas. Here, the authors use absorption spectroscopy in a total internal reflection geometry to probe solvated electrons generated at a plasma in contact with the surface of an aqueous solution
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18
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Glover WJ, Casey JR, Schwartz BJ. Free Energies of Quantum Particles: The Coupled-Perturbed Quantum Umbrella Sampling Method. J Chem Theory Comput 2014; 10:4661-71. [DOI: 10.1021/ct500661t] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- William J. Glover
- Department of Chemistry and
Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Jennifer R. Casey
- Department of Chemistry and
Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
| | - Benjamin J. Schwartz
- Department of Chemistry and
Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States
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19
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Turi L. Hydration dynamics in water clusters via quantum molecular dynamics simulations. J Chem Phys 2014; 140:204317. [DOI: 10.1063/1.4879517] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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20
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Yamamoto YI, Suzuki YI, Tomasello G, Horio T, Karashima S, Mitríc R, Suzuki T. Time- and angle-resolved photoemission spectroscopy of hydrated electrons near a liquid water surface. PHYSICAL REVIEW LETTERS 2014; 112:187603. [PMID: 24856723 DOI: 10.1103/physrevlett.112.187603] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Indexed: 05/05/2023]
Abstract
We present time- and angle-resolved photoemission spectroscopy of trapped electrons near liquid surfaces. Photoemission from the ground state of a hydrated electron at 260 nm is found to be isotropic, while anisotropic photoemission is observed for the excited states of 1,4-diazabicyclo[2,2,2]octane and I- in aqueous solutions. Our results indicate that surface and subsurface species create hydrated electrons in the bulk side. No signature of a surface-bound electron has been observed.
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Affiliation(s)
- Yo-ichi Yamamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Yoshi-Ichi Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan and RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan
| | - Gaia Tomasello
- Institut für Physikalishce und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Takuya Horio
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan and RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan and Japan Science and Technology Agency, CREST, Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan
| | - Shutaro Karashima
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Roland Mitríc
- Institut für Physikalishce und Theoretische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Toshinori Suzuki
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan and RIKEN Center for Advanced Photonics, RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan and Japan Science and Technology Agency, CREST, Sanbancho, Chiyoda-ku, Tokyo 102-0075, Japan
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21
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Bhattacharya SK, Inam F, Scandolo S. Excess electrons in ice: a density functional theory study. Phys Chem Chem Phys 2014; 16:3103-7. [PMID: 24401958 DOI: 10.1039/c3cp54921f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present a density functional theory study of the localization of excess electrons in the bulk and on the surface of crystalline and amorphous water ice. We analyze the initial stages of electron solvation in crystalline and amorphous ice. In the case of crystalline ice we find that excess electrons favor surface states over bulk states, even when the latter are localized at defect sites. In contrast, in amorphous ice excess electrons find it equally favorable to localize in bulk and in surface states which we attribute to the preexisting precursor states in the disordered structure. In all cases excess electrons are found to occupy the vacuum regions of the molecular network. The electron localization in the bulk of amorphous ice is assisted by its distorted hydrogen bonding network as opposed to the crystalline phase. Although qualitative, our results provide a simple interpretation of the large differences observed in the dynamics and localization of excess electrons in crystalline and amorphous ice films on metals.
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Affiliation(s)
- Somesh Kr Bhattacharya
- Abdus Salam International Center for Theoretical Physics, Strada Costiera 11, Trieste, I-34151, Italy.
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22
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Casey JR, Kahros A, Schwartz BJ. To be or not to be in a cavity: the hydrated electron dilemma. J Phys Chem B 2013; 117:14173-82. [PMID: 24160853 DOI: 10.1021/jp407912k] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hydrated electron-the species that results from the addition of a single excess electron to liquid water-has been the focus of much interest both because of its role in radiation chemistry and other chemical reactions, and because it provides for a deceptively simple system that can serve as a means to confront the predictions of quantum molecular dynamics simulations with experiment. Despite all this interest, there is still considerable debate over the molecular structure of the hydrated electron: does it occupy a cavity, have a significant number of interior water molecules, or have a structure somewhere in between? The reason for all this debate is that different computer simulations have produced each of these different structures, yet the predicted properties for these different structures are still in reasonable agreement with experiment. In this Feature Article, we explore the reasons underlying why different structures are produced when different pseudopotentials are used in quantum simulations of the hydrated electron. We also show that essentially all the different models for the hydrated electron, including those from fully ab initio calculations, have relatively little direct overlap of the electron's wave function with the nearby water molecules. Thus, a non-cavity hydrated electron is better thought of as an "inverse plum pudding" model, with interior waters that locally expel the surrounding electron's charge density. Finally, we also explore the agreement between different hydrated electron models and certain key experiments, such as resonance Raman spectroscopy and the temperature dependence and degree of homogeneous broadening of the optical absorption spectrum, in order to distinguish between the different simulated structures. Taken together, we conclude that the hydrated electron likely has a significant number of interior water molecules.
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Affiliation(s)
- Jennifer R Casey
- Department of Chemistry and Biochemistry, University of California, Los Angeles , Los Angeles, California 90095-1569, United States
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23
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Affiliation(s)
- Bernd Abel
- Leibniz Institute of Surface Modification (IOM), Chemical Department, D-04318 Leipzig, Germany, and Wilhelm-Ostwald Institute for Physical and Theoretical Chemistry, D-04103 Leipzig, Germany;
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24
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Uhlig F, Marsalek O, Jungwirth P. Electron at the Surface of Water: Dehydrated or Not? J Phys Chem Lett 2013; 4:338-343. [PMID: 26283445 DOI: 10.1021/jz3020953] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The hydrated electron is a crucial species in radiative processes, and it has been speculated that its behavior at the water surface could lead to specific interfacial chemical properties. Here, we address fundamental questions concerning the structure and energetics of an electron at the surface of water. We use the method of ab initio molecular dynamics, which was shown to provide a faithful description of solvated electrons in large water clusters and in bulk water. The present results clearly demonstrate that the surface electron is mostly buried in the interfacial water layer, with only about 10 % of its density protruding into the vapor phase. Consequently, it has a structure that is very similar to that of an electron solvated in the aqueous bulk. This points to a general feature of charges at the surface of water, namely, that they do not behave as half-dehydrated but rather as almost fully hydrated species.
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Affiliation(s)
- Frank Uhlig
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
| | - Ondrej Marsalek
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, CZ-16610 Prague 6, Czech Republic
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25
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Bounechada D, Fouladvand S, Kylhammar L, Pingel T, Olsson E, Skoglundh M, Gustafson J, Di Michiel M, Newton MA, Carlsson PA. Mechanisms behind sulfur promoted oxidation of methane. Phys Chem Chem Phys 2013; 15:8648-61. [DOI: 10.1039/c3cp44289f] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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26
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Turi L, Rossky PJ. Theoretical studies of spectroscopy and dynamics of hydrated electrons. Chem Rev 2012; 112:5641-74. [PMID: 22954423 DOI: 10.1021/cr300144z] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- László Turi
- Department of Physical Chemistry, Eötvös Loránd University, Budapest, Hungary.
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27
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Marsalek O, Elles CG, Pieniazek PA, Pluhařová E, VandeVondele J, Bradforth SE, Jungwirth P. Chasing charge localization and chemical reactivity following photoionization in liquid water. J Chem Phys 2012; 135:224510. [PMID: 22168706 DOI: 10.1063/1.3664746] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The ultrafast dynamics of the cationic hole formed in bulk liquid water following ionization is investigated by ab initio molecular dynamics simulations and an experimentally accessible signature is suggested that might be tracked by femtosecond pump-probe spectroscopy. This is one of the fastest fundamental processes occurring in radiation-induced chemistry in aqueous systems and biological tissue. However, unlike the excess electron formed in the same process, the nature and time evolution of the cationic hole has been hitherto little studied. Simulations show that an initially partially delocalized cationic hole localizes within ~30 fs after which proton transfer to a neighboring water molecule proceeds practically immediately, leading to the formation of the OH radical and the hydronium cation in a reaction which can be formally written as H(2)O(+) + H(2)O → OH + H(3)O(+). The exact amount of initial spin delocalization is, however, somewhat method dependent, being realistically described by approximate density functional theory methods corrected for the self-interaction error. Localization, and then the evolving separation of spin and charge, changes the electronic structure of the radical center. This is manifested in the spectrum of electronic excitations which is calculated for the ensemble of ab initio molecular dynamics trajectories using a quantum mechanics/molecular mechanics (QM∕MM) formalism applying the equation of motion coupled-clusters method to the radical core. A clear spectroscopic signature is predicted by the theoretical model: as the hole transforms into a hydroxyl radical, a transient electronic absorption in the visible shifts to the blue, growing toward the near ultraviolet. Experimental evidence for this primary radiation-induced process is sought using femtosecond photoionization of liquid water excited with two photons at 11 eV. Transient absorption measurements carried out with ~40 fs time resolution and broadband spectral probing across the near-UV and visible are presented and direct comparisons with the theoretical simulations are made. Within the sensitivity and time resolution of the current measurement, a matching spectral signature is not detected. This result is used to place an upper limit on the absorption strength and/or lifetime of the localized H(2)O(+) ((aq)) species.
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Affiliation(s)
- Ondrej Marsalek
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic and Center for Biomolecules and Complex Molecular Systems, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
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28
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Alexander WA, Wiens JP, Minton TK, Nathanson GM. Reactions of Solvated Electrons Initiated by Sodium Atom Ionization at the Vacuum-Liquid Interface. Science 2012; 335:1072-5. [DOI: 10.1126/science.1215956] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- William A. Alexander
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - Justin P. Wiens
- Department of Chemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Timothy K. Minton
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
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29
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Faubel M, Siefermann KR, Liu Y, Abel B. Ultrafast soft X-ray photoelectron spectroscopy at liquid water microjets. Acc Chem Res 2012; 45:120-30. [PMID: 22075058 DOI: 10.1021/ar200154w] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Since the pioneering work of Kai Siegbahn, electron spectroscopy for chemical analysis (ESCA) has been developed into an indispensable analytical technique for surface science. The value of this powerful method of photoelectron spectroscopy (PES, also termed photoemission spectroscopy) and Siegbahn's contributions were recognized in the 1981 Nobel Prize in Physics. The need for high vacuum, however, originally prohibited PES of volatile liquids, and only allowed for investigation of low-vapor-pressure molecules attached to a surface (or close to a surface) or liquid films of low volatility. Only with the invention of liquid beams of volatile liquids compatible with high-vacuum conditions was PES from liquid surfaces under vacuum made feasible. Because of the ubiquity of water interfaces in nature, the liquid water-vacuum interface became a most attractive research topic, particularly over the past 10 years. PES studies of these important aqueous interfaces remained significantly challenging because of the need to develop high-pressure PES methods. For decades, ESCA or PES (termed XPS, for X-ray photoelectron spectroscopy, in the case of soft X-ray photons) was restricted to conventional laboratory X-ray sources or beamlines in synchrotron facilities. This approach enabled frequency domain measurements, but with poor time resolution. Indirect access to time-resolved processes in the condensed phase was only achieved if line-widths could be analyzed or if processes could be related to a fast clock, that is, reference processes that are fast enough and are also well understood in the condensed phase. Just recently, the emergence of high harmonic light sources, providing short-wavelength radiation in ultrashort light pulses, added the dimension of time to the classical ESCA or XPS technique and opened the door to (soft) X-ray photoelectron spectroscopy with ultrahigh time resolution. The combination of high harmonic light sources (providing radiation with laserlike beam qualities) and liquid microjet technology recently enabled the first liquid interface PES experiments in the IR/UV-pump and extreme ultraviolet-probe (EUV-probe) configuration. In this Account, we highlight features of the technology and a number of recent applications, including extreme states of matter and the discovery and detection of short-lived transients of the solvated electron in water. Properties of the EUV radiation, such as its controllable polarization and features of the liquid microjet, will enable unique experiments in the near future. PES measures electron binding energies and angular distributions of photoelectrons, which comprise unique information about electron orbitals and their involvement in chemical bonding. One of the future goals is to use this information to trace molecular orbitals, over time, in chemical reactions or biological transformations.
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Affiliation(s)
- M. Faubel
- Max-Planck-Institut für Dynamik und Selbstorganisation, Bunsenstrasse 10, D-37073 Göttingen, Germany
| | - K. R. Siefermann
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road 2-306, Berkeley, California 94720, United States
| | - Y. Liu
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, University Leipzig, Linnéstrasse 2, D-04103 Leipzig, Germany
| | - B. Abel
- Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, University Leipzig, Linnéstrasse 2, D-04103 Leipzig, Germany
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30
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Herbert JM, Jacobson LD. Structure of the aqueous electron: assessment of one-electron pseudopotential models in comparison to experimental data and time-dependent density functional theory. J Phys Chem A 2011; 115:14470-83. [PMID: 22032635 DOI: 10.1021/jp206391d] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The prevailing structural paradigm for the aqueous electron is that of an s-like ground-state wave function that inhabits a quasi-spherical solvent cavity, a viewpoint that is supported by numerous atomistic simulations using various one-electron pseudopotential models. This conceptual picture has recently been challenged, however, on the basis of results obtained from a new electron-water pseudopotential model that predicts a more delocalized wave function and no well-defined solvent cavity. Here, we examine this new model in comparison to two alternative, cavity-forming pseudopotential models. We find that the cavity-forming models are far more consistent with the experimental data for the electron's radius of gyration, optical absorption spectrum, and vertical electron binding energy. Calculations of the absorption spectrum using time-dependent density functional theory are in quantitative or semiquantitative agreement with experiment when the solvent geometries are obtained from the cavity-forming pseudopotential models, but differ markedly from experiment when geometries that do not form a cavity are used.
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Affiliation(s)
- John M Herbert
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, United States.
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31
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Jacobson LD, Herbert JM. Theoretical Characterization of Four Distinct Isomer Types in Hydrated-Electron Clusters, and Proposed Assignments for Photoelectron Spectra of Water Cluster Anions. J Am Chem Soc 2011; 133:19889-99. [PMID: 22026436 DOI: 10.1021/ja208024p] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Leif D. Jacobson
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - John M. Herbert
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210, United States
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32
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Mones L, Rossky PJ, Turi L. Quantum-classical simulation of electron localization in negatively charged methanol clusters. J Chem Phys 2011; 135:084501. [PMID: 21895193 DOI: 10.1063/1.3624366] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Letif Mones
- Department of Physical Chemistry, Eötvös Loránd University, P. O. Box 32, H-1518, Budapest 112, Hungary.
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33
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Siefermann KR, Abel B. The Hydrated Electron: A Seemingly Familiar Chemical and Biological Transient. Angew Chem Int Ed Engl 2011; 50:5264-72. [DOI: 10.1002/anie.201006521] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 02/15/2011] [Indexed: 11/05/2022]
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34
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Siefermann KR, Abel B. Das hydratisierte Elektron - eine scheinbar vertraute transiente Spezies in chemischen und biologischen Systemen. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201006521] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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35
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Herbert JM, Jacobson LD. Nature's most squishy ion: The important role of solvent polarization in the description of the hydrated electron. INT REV PHYS CHEM 2011. [DOI: 10.1080/0144235x.2010.535342] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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36
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Jacobson LD, Herbert JM. A one-electron model for the aqueous electron that includes many-body electron-water polarization: Bulk equilibrium structure, vertical electron binding energy, and optical absorption spectrum. J Chem Phys 2010; 133:154506. [DOI: 10.1063/1.3490479] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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37
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Mones L, Rossky PJ, Turi L. Analysis of localization sites for an excess electron in neutral methanol clusters using approximate pseudopotential quantum-mechanical calculations. J Chem Phys 2010; 133:144510. [PMID: 20950020 DOI: 10.1063/1.3503506] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Letif Mones
- Department of Physical Chemistry, Eötvös Loránd University, Budapest 112, P. O. Box 32, H-1518, Hungary.
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38
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Abstract
The dynamics of hydrated electrons at the water/air interface are investigated using time-resolved second-harmonic generation spectroscopy. Initial solvation occurs in approximately 1 ps, and the electron remains at the interface for >750 ps. The location of the electron relative to the dividing surface is investigated using surfactants, which show that the electron is hydrated in the interfacial region, below the dividing surface.
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Affiliation(s)
- D M Sagar
- Department of Chemistry, University of Durham, South Road, Durham DH1 3LE, UK
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39
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Mones L, Turi L. A new electron-methanol molecule pseudopotential and its application for the solvated electron in methanol. J Chem Phys 2010; 132:154507. [DOI: 10.1063/1.3385798] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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40
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Binding energies, lifetimes and implications of bulk and interface solvated electrons in water. Nat Chem 2010; 2:274-9. [PMID: 21124507 DOI: 10.1038/nchem.580] [Citation(s) in RCA: 251] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 01/26/2010] [Indexed: 01/14/2023]
Abstract
Solvated electrons in liquid water are one of the seemingly simplest, but most important, transients in chemistry and biology, but they have resisted disclosing important information about their energetics, binding motifs and dynamics. Here we report the first ultrafast liquid-jet photoelectron spectroscopy measurements of solvated electrons in liquid water. The results prove unequivocally the existence of solvated electrons bound at the water surface and of solvated electrons in the bulk solution, with vertical binding energies of 1.6 eV and 3.3 eV, respectively, and with lifetimes longer than 100 ps. The unexpectedly long lifetime of solvated electrons bound at the water surface is attributed to a free-energy barrier that separates surface and interior states. Beyond constituting important energetic and kinetic benchmark and reference data, the results also help to understand the mechanisms of a number of very efficient electron-transfer processes in nature.
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41
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Madarász Á, Rossky PJ, Turi L. Response of Observables for Cold Anionic Water Clusters to Cluster Thermal History. J Phys Chem A 2010; 114:2331-7. [DOI: 10.1021/jp908876f] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Ádám Madarász
- Eötvös Loránd University, Department of Physical Chemistry, Budapest 112, P.O. Box 32, H-1518 Hungary, and Department of Chemistry and Biochemistry and Institute for Computational Engineering and Sciences, 1 University Station A5300, University of Texas at Austin, Austin, Texas 78712-1167
| | - Peter J. Rossky
- Eötvös Loránd University, Department of Physical Chemistry, Budapest 112, P.O. Box 32, H-1518 Hungary, and Department of Chemistry and Biochemistry and Institute for Computational Engineering and Sciences, 1 University Station A5300, University of Texas at Austin, Austin, Texas 78712-1167
| | - László Turi
- Eötvös Loránd University, Department of Physical Chemistry, Budapest 112, P.O. Box 32, H-1518 Hungary, and Department of Chemistry and Biochemistry and Institute for Computational Engineering and Sciences, 1 University Station A5300, University of Texas at Austin, Austin, Texas 78712-1167
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42
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Madarász A, Rossky PJ, Turi L. Interior- and surface-bound excess electron states in large water cluster anions. J Chem Phys 2009; 130:124319. [PMID: 19334842 DOI: 10.1063/1.3094732] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present the results of mixed quantum/classical simulations on relaxed thermal nanoscale water cluster anions, (H(2)O)(n)(-), with n=200, 500, 1000, and 8000. By using initial equilibration with constraints, we investigate stable/metastable negatively charged water clusters with both surface-bound and interior-bound excess electron states. Characterization of these states is performed in terms of geometrical parameters, energetics, and optical absorption spectroscopy of the clusters. The calculations provide data characterizing these states in the gap between previously published calculations and experiments on smaller clusters and the limiting cases of either an excess electron in bulk water or an excess electron at an infinite water/air interface. The present results are in general agreement with previous simulations and provide a consistent picture of the evolution of the physical properties of water cluster anions with size over the entire size range, including results for vertical detachment energies and absorption spectra that would signify their presence. In particular, the difference in size dependence between surface-bound and interior-bound state absorption spectra is dramatic, while for detachment energies the dependence is qualitatively the same.
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Affiliation(s)
- Adám Madarász
- Department of Physical Chemistry, Eötvös Loránd University, Budapest 112, P. O. Box 32, Budapest H-1518, Hungary.
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43
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Jacobson LD, Williams CF, Herbert JM. The static-exchange electron-water pseudopotential, in conjunction with a polarizable water model: A new Hamiltonian for hydrated-electron simulations. J Chem Phys 2009; 130:124115. [DOI: 10.1063/1.3089425] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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44
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Williams CF, Herbert JM. Influence of Structure on Electron Correlation Effects and Electron−Water Dispersion Interactions in Anionic Water Clusters. J Phys Chem A 2008; 112:6171-8. [DOI: 10.1021/jp802272r] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
| | - John M. Herbert
- Department of Chemistry, The Ohio State University, Columbus, Ohio 43210
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45
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Stähler J, Meyer M, Kusmierek DO, Bovensiepen U, Wolf M. Ultrafast Electron Transfer Dynamics at NH3/Cu(111) Interfaces: Determination of the Transient Tunneling Barrier. J Am Chem Soc 2008; 130:8797-803. [DOI: 10.1021/ja801682u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julia Stähler
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
| | - Michael Meyer
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
| | - Daniela O. Kusmierek
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
| | - Uwe Bovensiepen
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
| | - Martin Wolf
- Freie Universität Berlin, Fachbereich Physik, Arnimallee 14, 14195 Berlin, Germany
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46
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Zappa F, Denifl S, Mähr I, Bacher A, Echt O, Märk TD, Scheier P. Ultracold water cluster anions. J Am Chem Soc 2008; 130:5573-8. [PMID: 18373342 DOI: 10.1021/ja075421w] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Attachment of free electrons to water clusters embedded in helium droplets leads to water-cluster anions (H2O)n(-) and (D2O)n(-) of size n > or = 2. Small water-cluster anions bind to up to 10 helium atoms, providing compelling evidence for the low temperature of these complexes, but the most abundant species are bare cluster anions. In contrast to previous experiments on bare water clusters, which showed very pronounced magic and anti-magic anion sizes below n = 12, the presently observed size distributions vary much more smoothly, and all sizes are easily observed. Noticeable differences are also observed in the stoichiometry of fragment anions formed upon dissociative electron attachment and the energy dependence of their yield. Spectroscopic characterization of these ultracold water-cluster anions promises to unravel the relevance of metastable configurations in experiments and the nature of the still controversial bonding sites for the excess electron in small water-cluster anions.
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Affiliation(s)
- Fabio Zappa
- Institut für Ionenphysik und Angewandte Physik, Leopold Franzens Universität, Technikerstrasse 25, A-6020 Innsbruck, Austria
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Shkrob IA. On the nature of infrared absorbing trapped electron center in low-temperature ice-Ih. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.06.111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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