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Borgeaud Dit Avocat DP, Yang H, Nitsche A, Wenger J, Yoder BL, Signorell R. Out-of-focus spatial map imaging of magnetically deflected sodium ammonia clusters. Phys Chem Chem Phys 2024; 26:16972-16979. [PMID: 38842057 PMCID: PMC11186454 DOI: 10.1039/d4cp00788c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/23/2024] [Indexed: 06/07/2024]
Abstract
This paper introduces out-of-focus spatial map imaging (SMI) as a detection method for magnetic deflection of molecular/cluster beams, using Nam(NH3)n to illustrate its capabilities. This method enables imaging of the complete spatial distribution, simplifying measurements and allowing for cluster-size-resolved analysis by shifting away from traditional in-focus SMI conditions. Incorporating out-of-focus SMI with TOF-MS and velocity map imaging into a single setup allows for direct assessment of clusters' magnetic moments without needing to pre-select velocities. Key findings include a slower relaxation for Na(NH3)4 compared to Na(NH3)3 and Na(NH3)5, unexpectedly high deflection for larger clusters up to Na(NH3)9, hinting at changes in cluster dynamics as the first solvation shell closes. The study also covers the first measurements of Na2(NH3)1 and Na3(NH3)n, showing distinct deflection behaviors and underscoring the improved capabilities of the new detection method.
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Affiliation(s)
| | - H Yang
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - A Nitsche
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - J Wenger
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - B L Yoder
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
| | - R Signorell
- Department of Chemistry and Applied Biosciences, ETH Zurich, CH-8093 Zurich, Switzerland.
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2
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Barnes J, Borgeaud dit Avocat DP, Simmen E, Yang H, Yoder BL, Signorell R. Comparison of Magnetic Deflection among Neutral Sodium-Doped Clusters: Na(H 2O) n, Na(NH 3) n, Na(MeOH) n, and Na(DME) n. J Phys Chem A 2023; 127:8544-8555. [PMID: 37794760 PMCID: PMC10591511 DOI: 10.1021/acs.jpca.3c03820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 09/06/2023] [Indexed: 10/06/2023]
Abstract
Using a pulsed Stern-Gerlach deflection experiment, we present the results of a comparative study on the magnetic properties of neutral sodium-doped solvent clusters Na(Sol)n with n = 1-4 (Sol: H2O, NH3, CH3OH, CH3OCH3). Experimental deflection ratios are compared with values calculated from molecular dynamics simulations. NaNH3 and NaH2O are deflected as a spin 1/2 system, consistent with spin transitions occurring on a time scale significantly longer than 100 μs. For all other clusters, reduced deflection is observed. The observed magnetic deflection behavior is correlated to the number of thermally populated rotational states in the clusters. We discuss that spin-rotational couplings allow for avoided crossings and a reduction in the effective magnetic moment of the cluster. This work attempts to understand the evolution of magnetic properties in isolated weakly bound clusters and is relevant to diamagnetic and paramagnetic species expected to exist in solvated electron systems.
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Affiliation(s)
- Jonathan
V. Barnes
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland
| | | | - Edith Simmen
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland
| | - Huanyu Yang
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland
| | - Bruce L. Yoder
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland
| | - Ruth Signorell
- Department of Chemistry and
Applied Biosciences, ETH Zürich, Vladimir-Prelog-Weg 2, Zürich 8093, Switzerland
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3
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Dong H, Feng Y, Bu Y. Electron Presolvation in Tetrahydrofuran-Incorporated Supramolecular Sodium Entities. J Phys Chem A 2023; 127:1402-1412. [PMID: 36748233 DOI: 10.1021/acs.jpca.2c06944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Alkali metal atoms can repopulate their valence electrons toward solvation due to impact from solvents or microsurroundings and provide the remaining alkali metal cations for coordinating with a variety of specific solvents, forming various electron-expanded complexes or solvated ionic pairs with special interactions. Such special solute-solvent interactions not only affect their electronic structures but also enable the formation of entirely new species. Taking Na(THF)n (n = 1-6, THF = tetrahydrofuran) and Na2@THF complexes as typical representatives, density functional theory calculations are carried out to explore the solvation of a sodium atom and its dimer in THF and characterize their complexes as solvent-incorporated supramolecular entities and particularly valence electron presolvation due to their interaction with solvent THF. Electron presolvation is caused by the Pauli repulsion between THF containing a coordinating O atom with a lone pair of electrons and the alkali metal Na or Na2 containing valence electrons, and THF coordination to them forces their valence electrons to redistribute, which can be easily realized in such solvents. Compared with strongly bound valance electrons of alkali metal atoms, THF coordination enables Na or Na2 electrons to exhibit much more active states (i.e., the presolvated states) featuring small vertical detachment energies of electrons and distorted diffuse distributions in the frames of the generally structured metal cation complexes, acting as the electron-expanded chemical entities. Furthermore, the degree of electron diffusion and the polarity of the Na-Na bond are proportional to the coordination number (n) and the coordination number difference (Δn) between two Na centers in Na2@THF. The unique properties of such entities are also discussed. This work offers a theoretical support to the supramolecular entities formed by alkali-metal atoms or their dimers with ligands containing O or N and uncovers the unique electron presolvation phenomena and also enriches our understanding of the novel metal atom complexes.
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Affiliation(s)
- Hui Dong
- School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, P. R. China
| | - Yiwei Feng
- School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, P. R. China
| | - Yuxiang Bu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan250100, P. R. China
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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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Abstract
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Cluster-size-resolved
ultrafast dynamics of the solvated electron
in neutral water clusters with n = 3 to ∼200
molecules are studied with pump–probe time-of-flight mass spectrometry
after below band gap excitation. For the smallest clusters, no longer-lived
(>100–200 fs) hydrated electrons were detected, indicating
a minimum size of n ∼ 14 for being able to
sustain hydrated electrons. Larger clusters show a systematic increase
of the number of hydrated electrons per molecule on the femtosecond
to picosecond time scale. We propose that with increasing cluster
size the underlying dynamics is governed by more effective electron
formation processes combined with less effective electron loss processes,
such as ultrafast hydrogen ejection and recombination. It appears
unlikely that any size dependence of the solvent relaxation dynamics
would be reflected in the observed time-resolved ion yields.
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Affiliation(s)
- Loren Ban
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
| | - Bruce L Yoder
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
| | - Ruth Signorell
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 2, CH-8093 Zurich, Switzerland
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Fuchs TM, Schäfer R. Influence of nuclear spins on electron spin coherence in isolated, p-doped tin clusters. Phys Chem Chem Phys 2021; 23:11334-11344. [PMID: 33959734 DOI: 10.1039/d1cp01227d] [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
Magnetic double deflection experiments reveal that nuclear spins diminish electron spin coherence in isolated AlSn12 clusters. A temperature-dependent fraction of the endohedral cage clusters show superatomic response in Stern-Gerlach experiments which allows one to detect spin flips under controlled conditions in a double deflection arrangement. The concentration of nuclear spins in the tin cage is varied by using isotopically enriched tin samples. Hyperfine interaction, nuclear spin statistics and spin dynamics are discussed in detail. It is demonstrated that state-interference in the multistate Landau-Zener system AlSn12 explains why the spin decoherence is significantly increased when one or two nuclear spins are already present in the cluster, while the spin coherence no longer changes significantly with the addition of further nuclear spins.
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Affiliation(s)
- Thomas M Fuchs
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, Darmstadt, Germany.
| | - Rolf Schäfer
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, Alarich-Weiss-Str. 8, Darmstadt, Germany.
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Rivic F, Fuchs TM, Schäfer R. Discriminating the influence of thermal excitation and the presence of structural isomers on the Stark and Zeeman effect of AlSn12 clusters by combined electric and magnetic beam deflection experiments. Phys Chem Chem Phys 2021; 23:9971-9979. [DOI: 10.1039/d1cp00351h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A combination of electric and magnetic beam deflection experiments shows a connection between non-polar and superatomic species for AlSn12 clusters.
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Affiliation(s)
- Filip Rivic
- Technische Universität Darmstadt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie
- 64287 Darmstadt
- Germany
| | - Thomas M. Fuchs
- Technische Universität Darmstadt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie
- 64287 Darmstadt
- Germany
| | - Rolf Schäfer
- Technische Universität Darmstadt
- Eduard-Zintl-Institut für Anorganische und Physikalische Chemie
- 64287 Darmstadt
- Germany
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