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Jackson BA, Khan SN, Miliordos E. A fresh perspective on metal ammonia molecular complexes and expanded metals: opportunities in catalysis and quantum information. Chem Commun (Camb) 2023; 59:10572-10587. [PMID: 37555315 DOI: 10.1039/d3cc02956e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Recent advances in our comprehension of the electronic structure of metal ammonia complexes have opened avenues for novel materials with diffuse electrons. These complexes in their ground state can host peripheral "Rydberg" electrons which populate a hydrogenic-type shell model imitating atoms. Aggregates of such complexes form the so-called expanded or liquid metals. Expanded metals composed of d- and f-block metal ammonia complexes offer properties, such as magnetic moments and larger numbers of diffuse electrons, not present for alkali and alkaline earth (s-block) metals. In addition, tethering metal ammonia complexes via hydrocarbon chains (replacement of ammonia ligands with diamines) yields materials that can be used for redox catalysis and quantum computing, sensing, and optics. This perspective summarizes the recent findings for gas-phase isolated metal ammonia complexes and projects the obtained knowledge to the condensed phase regime. Possible applications for the newly introduced expanded metals and linked solvated electrons precursors are discussed and future directions are proposed.
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Affiliation(s)
- Benjamin A Jackson
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
| | - Shahriar N Khan
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849-5312, USA.
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2
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Nicholas TC, Headen TF, Wasse JC, Howard CA, Skipper NT, Seel AG. Intermediate Range Order in Metal-Ammonia Solutions: Pure and Na-Doped Ca-NH 3. J Phys Chem B 2021; 125:7456-7461. [PMID: 34212732 PMCID: PMC8389892 DOI: 10.1021/acs.jpcb.1c03843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The local and intermediate range ordering in Ca-NH3 solutions in their metallic phase is determined through H/D isotopically differenced neutron diffraction in combination with empirical potential structure refinements. For both low and high relative Ca concentrations, the Ca ions are found to be octahedrally coordinated by the NH3 solvent, and these hexammine units are spatially correlated out to lengthscales of ∼7.4-10.3 Å depending on the concentration, leading to pronounced ordering in the bulk liquid. We further demonstrate that this liquid order can be progressively disrupted by the substitution of Ca for Na, whereby a distortion of the average ion primary solvation occurs and the intermediate range ion-ion correlations are disrupted.
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Affiliation(s)
- Thomas C Nicholas
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - Thomas F Headen
- ISIS Spallation Neutron and Muon Source, STFC Rutherford Appleton Laboratory, Didcot, Oxfordshire OX11 0QX, U.K
| | - Jonathan C Wasse
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
| | - Christopher A Howard
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
| | - Neal T Skipper
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
| | - Andrew G Seel
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
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3
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Mason PE, Schewe HC, Buttersack T, Kostal V, Vitek M, McMullen RS, Ali H, Trinter F, Lee C, Neumark DM, Thürmer S, Seidel R, Winter B, Bradforth SE, Jungwirth P. Spectroscopic evidence for a gold-coloured metallic water solution. Nature 2021; 595:673-676. [PMID: 34321671 DOI: 10.1038/s41586-021-03646-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 05/14/2021] [Indexed: 02/04/2023]
Abstract
Insulating materials can in principle be made metallic by applying pressure. In the case of pure water, this is estimated1 to require a pressure of 48 megabar, which is beyond current experimental capabilities and may only exist in the interior of large planets or stars2-4. Indeed, recent estimates and experiments indicate that water at pressures accessible in the laboratory will at best be superionic with high protonic conductivity5, but not metallic with conductive electrons1. Here we show that a metallic water solution can be prepared by massive doping with electrons upon reacting water with alkali metals. Although analogous metallic solutions of liquid ammonia with high concentrations of solvated electrons have long been known and characterized6-9, the explosive interaction between alkali metals and water10,11 has so far only permitted the preparation of aqueous solutions with low, submetallic electron concentrations12-14. We found that the explosive behaviour of the water-alkali metal reaction can be suppressed by adsorbing water vapour at a low pressure of about 10-4 millibar onto liquid sodium-potassium alloy drops ejected into a vacuum chamber. This set-up leads to the formation of a transient gold-coloured layer of a metallic water solution covering the metal alloy drops. The metallic character of this layer, doped with around 5 × 1021 electrons per cubic centimetre, is confirmed using optical reflection and synchrotron X-ray photoelectron spectroscopies.
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Affiliation(s)
- Philip E Mason
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - H Christian Schewe
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.,Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Tillmann Buttersack
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.,Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany.,Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Vojtech Kostal
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Marco Vitek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Ryan S McMullen
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Hebatallah Ali
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany.,Department of Physics, Faculty of Women for Art, Science and Education, Ain Shams University, Cairo, Egypt
| | - Florian Trinter
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany.,Photon Science, Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany.,Institut für Kernphysik, Goethe-Universität Frankfurt, Frankfurt am Main, Germany
| | - Chin Lee
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany.,Department of Chemistry, University of California, Berkeley, CA, USA.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Daniel M Neumark
- Department of Chemistry, University of California, Berkeley, CA, USA.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Stephan Thürmer
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Robert Seidel
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany.,Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Bernd Winter
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany
| | - Stephen E Bradforth
- Department of Chemistry, University of Southern California, Los Angeles, CA, USA
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic.
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4
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Angel GMA, Mansor N, Jervis R, Rana Z, Gibbs C, Seel A, Kilpatrick AFR, Shearing PR, Howard CA, Brett DJL, Cullen PL. Realising the electrochemical stability of graphene: scalable synthesis of an ultra-durable platinum catalyst for the oxygen reduction reaction. NANOSCALE 2020; 12:16113-16122. [PMID: 32699875 DOI: 10.1039/d0nr03326j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Creating effective and stable catalyst nanoparticle-coated electrodes that can withstand extensive cycling is a current roadblock in realising the potential of polymer electrolyte membrane fuel cells. Graphene has been proposed as an ideal electrode support material due to its corrosion resistance, high surface area and high conductivity. However, to date, graphene-based electrodes suffer from high defect concentrations and non-uniform nanoparticle coverage that negatively affects performance; moreover, production methods are difficult to scale. Herein we describe a scalable synthesis for Pt nanoparticle-coated graphene whereby PtCl2 is reduced directly by negatively charged single layer graphene sheets in solution. The resultant nanoparticles are of optimal dimensions and can be uniformly dispersed, yielding high catalytic activity, remarkable stability, and showing a much smaller decrease in electrochemical surface area compared with an optimised commercial catalyst over 30 000 cycles. The stability is rationalised by identical location TEM which shows minimal nanoparticle agglomeration and no nanoparticle detachment.
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Affiliation(s)
- Gyen Ming A Angel
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK.
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5
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Isborn CM. The link between electrolytes and metals. Science 2020; 368:1056-1057. [PMID: 32499427 DOI: 10.1126/science.abb9717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Christine M Isborn
- Chemistry and Chemical Biology, University of California Merced, Merced, CA 95343, USA.
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6
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Buttersack T, Mason PE, McMullen RS, Schewe HC, Martinek T, Brezina K, Crhan M, Gomez A, Hein D, Wartner G, Seidel R, Ali H, Thürmer S, Marsalek O, Winter B, Bradforth SE, Jungwirth P. Photoelectron spectra of alkali metal–ammonia microjets: From blue electrolyte to bronze metal. Science 2020; 368:1086-1091. [DOI: 10.1126/science.aaz7607] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/25/2020] [Accepted: 04/03/2020] [Indexed: 11/02/2022]
Affiliation(s)
- Tillmann Buttersack
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-0482, USA
| | - Philip E. Mason
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Ryan S. McMullen
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-0482, USA
| | - H. Christian Schewe
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Tomas Martinek
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Krystof Brezina
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Charles University, Faculty of Mathematics and Physics, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - Martin Crhan
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
| | - Axel Gomez
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
- Département de Chimie, École Normale Supérieure, PSL University, 75005 Paris, France
| | - Dennis Hein
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany
| | - Garlef Wartner
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany
| | - Robert Seidel
- Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, D-12489 Berlin, Germany
| | - Hebatallah Ali
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Stephan Thürmer
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-Ku, Kyoto 606-8502, Japan
| | - Ondrej Marsalek
- Charles University, Faculty of Mathematics and Physics, Ke Karlovu 3, 121 16 Prague 2, Czech Republic
| | - Bernd Winter
- Molecular Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany
| | - Stephen E. Bradforth
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089-0482, USA
| | - Pavel Jungwirth
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Flemingovo nám. 2, 16610 Prague 6, Czech Republic
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7
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Zhang C, Luo Q, Cheng S, Bu Y. Unusual Indirect Nuclear Spin-Spin Exchange Coupling through Solvated Electron. J Phys Chem Lett 2018; 9:689-695. [PMID: 29369635 DOI: 10.1021/acs.jpclett.7b03249] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Solvated electrons have been found to exist in various media which also exhibit more intriguing properties such as superconductivity, nonlinear optical response, and so on. However, how they affect the nuclear spin properties has not been proven. In this work, we present the first detailed study on solvated-electron-triggered indirect nuclear spin-spin J-coupling using density functional theory calculations. Taking 19F as a probe, we verify the presence of unusual J couplings between two distant F atoms in HF-containing anionic clusters. These couplings occur "through solvated electron", rather than through conventional covalent bonds or space. Solvated electron can serve as an additional channel to efficiently realize long-range J-coupling between far separated nuclei because of its dispersivity and Rydberg character. The coupling magnitude strongly depends on the unique distribution of solvated electron and its second-order interaction with solvating HF units. This work provides novel insights into the mediating roles of electrons, possibly opening up potential applications based on weakly bound electrons.
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Affiliation(s)
- Changzhe Zhang
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
| | - Qi Luo
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
| | - Shibo Cheng
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University , Jinan, 250100, People's Republic of China
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8
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Lamontagne LK, Laurita G, Knight M, Yusuf H, Hu J, Seshadri R, Page K. The Role of Structural and Compositional Heterogeneities in the Insulator-to-Metal Transition in Hole-Doped APd 3O 4 (A = Ca, Sr). Inorg Chem 2017; 56:5158-5164. [PMID: 28406617 DOI: 10.1021/acs.inorgchem.7b00307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The cubic semiconducting compounds APd3O4 (A = Ca, Sr) can be hole-doped by Na substitution on the A site and driven toward more conducting states. This process has been followed here by a number of experimental techniques to understand the evolution of electronic properties. While an insulator-to-metal transition is observed in Ca1-xNaxPd3O4 for x ≥ 0.15, bulk metallic behavior is not observed for Sr1-xNaxPd3O4 up to x = 0.20. Given the very similar crystal and (calculated) electronic structures of the two materials, the distinct behavior is a matter of interest. We present evidence of local disorder in the A = Sr materials through the analysis of the neutron pair distribution function, which is potentially at the heart of the distinct behavior. Solid-state 23Na nuclear magnetic resonance studies additionally suggest a percolative insulator-to-metal transition mechanism, wherein presumably small regions with a signal resembling metallic NaPd3O4 form almost immediately upon Na substitution, and this signal grows monotonically with substitution. Some signatures of increased local disorder and a propensity for Na clustering are seen in the A = Sr compounds.
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Affiliation(s)
| | | | | | | | | | | | - Katharine Page
- Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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9
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Seel AG, Swan H, Bowron DT, Wasse JC, Weller T, Edwards PP, Howard CA, Skipper NT. Electron Solvation and the Unique Liquid Structure of a Mixed-Amine Expanded Metal: The Saturated Li-NH 3 -MeNH 2 System. Angew Chem Int Ed Engl 2017; 56:1561-1565. [PMID: 28071838 PMCID: PMC5396365 DOI: 10.1002/anie.201609192] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/02/2016] [Indexed: 11/12/2022]
Abstract
Metal-amine solutions provide a unique arena in which to study electrons in solution, and to tune the electron density from the extremes of electrolytic through to true metallic behavior. The existence and structure of a new class of concentrated metal-amine liquid, Li-NH3 -MeNH2 , is presented in which the mixed solvent produces a novel type of electron solvation and delocalization that is fundamentally different from either of the constituent systems. NMR, ESR, and neutron diffraction allow the environment of the solvated electron and liquid structure to be precisely interrogated. Unexpectedly it was found that the solution is truly homogeneous and metallic. Equally surprising was the observation of strong longer-range order in this mixed solvent system. This is despite the heterogeneity of the cation solvation, and it is concluded that the solvated electron itself acts as a structural template. This is a quite remarkable observation, given that the liquid is metallic.
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Affiliation(s)
- Andrew G Seel
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
| | - Helen Swan
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK.,National Nuclear Laboratory, Culham Science Centre, Abingdon, OX14 3DB, UK
| | - Daniel T Bowron
- ISIS Spallation Neutron Source, STFC Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK
| | - Jonathan C Wasse
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - Thomas Weller
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - Peter P Edwards
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK
| | - Christopher A Howard
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
| | - Neal T Skipper
- Department of Physics and Astronomy, University College London, Gower Street, London, WC1E 6BT, UK
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10
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Electron Solvation and the Unique Liquid Structure of a Mixed-Amine Expanded Metal: The Saturated Li-NH3
-MeNH2
System. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201609192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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11
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Janesko BG, Scalmani G, Frisch MJ. Quantifying solvated electrons' delocalization. Phys Chem Chem Phys 2015; 17:18305-17. [DOI: 10.1039/c5cp01967b] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electron delocalization range EDR(r;uav) (left) captures the spin density (right) of an electron delocalized over uav = 5.77 Å on the surface of an (H2O)20− cluster.
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