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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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Ariyarathna IR, Miliordos E. Ground and excited states analysis of alkali metal ethylenediamine and crown ether complexes. Phys Chem Chem Phys 2021; 23:20298-20306. [PMID: 34486608 DOI: 10.1039/d1cp02552j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-level electronic structure calculations are carried out to obtain optimized geometries and excitation energies of neutral lithium, sodium, and potassium complexes with two ethylenediamine and one or two crown ether molecules. Three different sizes of crowns are employed (12-crown-4, 15-crown-5, 18-crown-6). The ground state of all complexes contains an electron in an s-type orbital. For the mono-crown ether complexes, this orbital is the polarized valence s-orbital of the metal, but for the other systems this orbital is a peripheral diffuse orbital. The nature of the low-lying electronic states is found to be different for each of these species. Specifically, the metal ethylenediamine complexes follow the previously discovered shell model of metal ammonia complexes (1s, 1p, 1d, 2s, 1f), but both mono- and sandwich di-crown ether complexes bear a different shell model partially due to their lower (cylindrical) symmetry and the stabilization of the 2s-type orbital. Li(15-crown-5) is the only complex with the metal in the middle of the crown ether and adopts closely the shell model of metal ammonia complexes. Our findings suggest that the electronic band structure of electrides (metal crown ether sandwich aggregates) and expanded metals (metal ammonia aggregates) should be different despite the similar nature of these systems (bearing diffuse electrons around a metal complex).
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Affiliation(s)
- Isuru R Ariyarathna
- 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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Jackson BA, Miliordos E. Electronic and geometric structure of cationic and neutral chromium and molybdenum ammonia complexes. J Chem Phys 2021; 155:014303. [PMID: 34241410 DOI: 10.1063/5.0054648] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
High level quantum chemical approaches are used to study the geometric and electronic structures of M(NH3)n and M(NH3)n + (M = Cr, Mo for n = 1-6). These complexes possess a dual shell electronic structure of the inner metal (3d or 4d) orbitals and the outer diffuse orbitals surrounding the periphery of the complex. Electronic excitations reveal these two shells to be virtually independent of the other. Molybdenum and chromium ammonia complexes are found to differ significantly in geometry with the former adopting an octahedral geometry and the latter a Jahn-Teller distorted octahedral structure where only the axial distortion is stable. The hexa-coordinated complexes and the tetra-coordinated complexes with two ammonia molecules in the second solvation shell are found to be energetically competitive. Electronic excitation energies and computed IR spectra are provided to allow the two isomers to be experimentally distinguished. This work is a component of an ongoing effort to study the periodic trends of transition metal solvated electron precursors.
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Affiliation(s)
- Benjamin A Jackson
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, USA
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, USA
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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: 14] [Impact Index Per Article: 2.0] [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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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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Hayama S, Wasse JC, Skipper NT, Soper AK. Structure of Solutions of Lithium in Methylamine across the Metal−Nonmetal Transition. J Phys Chem B 2001. [DOI: 10.1021/jp0155361] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shusaku Hayama
- Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, U.K
| | - Jonathan C. Wasse
- 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
| | - Alan K. Soper
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OXON OX11 0QX, U.K
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DeBacker MG, Mkadmi EB, Sauvage FX, Lelieur JP, Wagner MJ, Concepcion R, Kim J, McMills LEH, Dye JL. The Lithium−Sodium−Methylamine System: Does a Low-Melting Sodide Become a Liquid Metal? J Am Chem Soc 1996. [DOI: 10.1021/ja952634p] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marc G. DeBacker
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - El Bachir Mkadmi
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - François X. Sauvage
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - Jean-Pierre Lelieur
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - Michael J. Wagner
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - Rosario Concepcion
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - Jineun Kim
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - Lauren E. H. McMills
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
| | - James L. Dye
- Contribution from LASIR-HEI CNRS LP2631, 13 rue de Toul, 59046 Lille Cedex, France, and Department of Chemistry and Center for Fundamental Materials Research, Michigan State University, East Lansing, Michigan 48824
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Anomalies in the properties of Hf(S2−xTex)1−y and Hf(Se2−xTex)1−y near the metal-insulator transition. J SOLID STATE CHEM 1984. [DOI: 10.1016/0022-4596(84)90176-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Stacy AM, Edwards PP, Sienko M. Electron-electron interactions in expanded-metal compounds. J SOLID STATE CHEM 1982. [DOI: 10.1016/0022-4596(82)90291-2] [Citation(s) in RCA: 12] [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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