1
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Schmitt MJP, Kruppa SV, Walg SP, Thiel WR, Klopper W, Riehn C. Electronic spectroscopy of homo- and heterometallic binuclear coinage metal phosphine complexes in isolation. Phys Chem Chem Phys 2023; 25:20880-20891. [PMID: 37525899 DOI: 10.1039/d3cp03058j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Binuclear coinage metal phosphine complexes are examined under ion trap isolation in order to elucidate their noncovalent binding, structural properties and intrinsic electronic spectra. Our survey shows an intriguing order of electronic transitions obtained by in situ synthesis and mass-spectrometrically supported UV photodissociation spectroscopy on a series of six isolated homo- and heterobinuclear complexes of type [MM'(dcpm)2]2+ (M, M' = CuI, AgI, AuI; dcpm = bis(dicyclohexyl-phosphino)methane). This approach provides the unique opportunity to study all possible coinage metal interactions within a fixed ligand framework. A successive blue-shift (33 700-38 500 cm-1; 297-260 nm) of the lowest-energy bright electronic transition energy in gas phase was observed in the order of Cu2 < CuAu < CuAg < Au2 < AgAu < Ag2. This order was reproduced by quantum chemical calculations using a scalar-relativistic GW-Bethe-Salpeter-equation (GW-BSE) approach. Theory ascribes the electronic bands of all complexes to metal-centered 1MC(dσ*-pσ) transitions revealing a strengthening of metal-metal' (M-M') binding upon excitation, in agreement to mass spetrometric results. A test of the correlation of transition energies with M-M' distance by quantum chemical calculations of single point energies as a function of intermetallic distance indicates qualitative agreement with experimental results. However, the experimentally observed high sensitivity of spectroscopic shifts towards metal composition cannot be accounted for solely by M-M' distance variation. The differences in electronic transitions are qualitatively rationalized by the varying (n + 1)s (n = 3, 4, 5) orbital contributions (increase from Cu2via CuAu/CuAg to Au2/AgAu/Ag2) within the nd(n + 1)s/p-hybridization for the ground electronic state of the different complexes, whereas the excited state (of (n + 1)p orbital character) shows significantly less variation in energy. In particular, the observed spectroscopic and mass spectrometric sequence for the Ag/Au complexes is traced back to the interplay of Pauli repulsion and variation in metal-ligand bond strength within the orbital hybridization model.
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Affiliation(s)
- Marcel J P Schmitt
- Department of Chemistry, Rheinland-Pfälzische Technische Universität (RPTU) Kaiserslautern-Landau, Erwin-Schrödinger Str. 53, 67663 Kaiserslautern, Germany.
| | - Sebastian V Kruppa
- Department of Chemistry, Rheinland-Pfälzische Technische Universität (RPTU) Kaiserslautern-Landau, Erwin-Schrödinger Str. 53, 67663 Kaiserslautern, Germany.
| | - Simon P Walg
- Department of Chemistry, Rheinland-Pfälzische Technische Universität (RPTU) Kaiserslautern-Landau, Erwin-Schrödinger Str. 53, 67663 Kaiserslautern, Germany.
| | - Werner R Thiel
- Department of Chemistry, Rheinland-Pfälzische Technische Universität (RPTU) Kaiserslautern-Landau, Erwin-Schrödinger Str. 53, 67663 Kaiserslautern, Germany.
| | - Wim Klopper
- Institute of Physical Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 2, 76131 Karlsruhe, Germany.
| | - Christoph Riehn
- Department of Chemistry, Rheinland-Pfälzische Technische Universität (RPTU) Kaiserslautern-Landau, Erwin-Schrödinger Str. 53, 67663 Kaiserslautern, Germany.
- Research Center OPTIMAS, Erwin-Schrödinger Str. 46, 67663 Kaiserslautern, Germany
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2
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Ferrari P, Kaw KA, Lievens P, Janssens E. Radiative cooling in silver and palladium doped gold clusters. Faraday Discuss 2023; 242:269-285. [PMID: 36168998 DOI: 10.1039/d2fd00090c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The emission of photons from a thermally populated electronic excited state, via the process of recurrent fluorescence, has been recognized as a prominent cooling channel in hot molecules and small metal clusters. For the latter case, however, only monometallic species have been investigated to date. An active radiative cooling channel has a stabilizing effect and can favor the size and composition specific production of selected clusters. In this work, the influence of silver and palladium doping on the radiative cooling of gold cluster cations is studied. The quenching of metastable fragmentation due to radiation of laser-excited Aun+, AgAun-1+ and PdAun-1+ (n = 11-15) clusters is investigated in a single-pass molecular beam setup. The observed high radiation rates, with values in the range from 103 to 105 s-1, are consistent with recurrent fluorescence. The rates present a pronounced odd-even staggering with higher values for the clusters with closed-shell electronic configurations. While substitution of Au with Ag does not alter the odd-even pattern with cluster size, replacing Au with Pd shifts the pattern by one atom. The experimental observations are discussed in terms of the dissociation energy of the clusters, which sets their effective temperature during photon emission, and the low-lying electronic excited states involved in the photon emission process. Linear-response time-dependent density functional theory calculations on selected species are used to illustrate the significant effect of the electronic structure on the radiation rates. For n = 14, substitution of Au with Ag lowers the energy of the lowest-energy transition in the cluster, which in addition has a higher oscillator strength, favoring radiative cooling. The opposite effect is seen in Pd doped clusters. Based on this analysis, conclusions can be drawn about the significance of radiative cooling in laser-excited alloy clusters, with a concomitant fast stabilization at high internal energy conditions.
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Affiliation(s)
- Piero Ferrari
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, Leuven 3001, Belgium.
| | - Kevin Anthony Kaw
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, Leuven 3001, Belgium.
| | - Peter Lievens
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, Leuven 3001, Belgium.
| | - Ewald Janssens
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200d, Leuven 3001, Belgium.
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3
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Ramasanoff RR, Sokolov PA. Intersystem Crossing Rates of Violet-, Green- and Red-emitting DNA Stabilized Silver Luminescent Clusters. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.140081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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4
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Buntine JT, Carrascosa E, Bull JN, Jacovella U, Cotter MI, Watkins P, Liu C, Scholz MS, Adamson BD, Marlton SJP, Bieske EJ. An ion mobility mass spectrometer coupled with a cryogenic ion trap for recording electronic spectra of charged, isomer-selected clusters. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2022; 93:043201. [PMID: 35489918 DOI: 10.1063/5.0085680] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Infrared and electronic spectra are indispensable for understanding the structural and energetic properties of charged molecules and clusters in the gas phase. However, the presence of isomers can potentially complicate the interpretation of spectra, even if the target molecules or clusters are mass-selected beforehand. Here, we describe an instrument for spectroscopically characterizing charged molecular clusters that have been selected according to both their isomeric form and their mass-to-charge ratio. Cluster ions generated by laser ablation of a solid sample are selected according to their collision cross sections with helium buffer gas using a drift tube ion mobility spectrometer and their mass-to-charge ratio using a quadrupole mass filter. The mobility- and mass-selected target ions are introduced into a cryogenically cooled, three-dimensional quadrupole ion trap where they are thermalized through inelastic collisions with an inert buffer gas (He or He/N2 mixture). Spectra of the molecular ions are obtained by tagging them with inert atoms or molecules (Ne and N2), which are dislodged following resonant excitation of an electronic transition, or by photodissociating the cluster itself following absorption of one or more photons. An electronic spectrum is generated by monitoring the charged photofragment yield as a function of wavelength. The capacity of the instrument is illustrated with the resonance-enhanced photodissociation action spectra of carbon clusters (Cn +) and polyacetylene cations (HC2nH+) that have been selected according to the mass-to-charge ratio and collision cross section with He buffer gas and of mass-selected Au2 + and Au2Ag+ clusters.
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Affiliation(s)
- Jack T Buntine
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Eduardo Carrascosa
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - James N Bull
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Ugo Jacovella
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Mariah I Cotter
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Patrick Watkins
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Chang Liu
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Michael S Scholz
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Brian D Adamson
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Samuel J P Marlton
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
| | - Evan J Bieske
- School of Chemistry, The University of Melbourne, Victoria 3010, Australia
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5
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Förstel M, Pollow K, Studemund T, Dopfer O. Near-Infrared Spectrum of the First Excited State of Au 2. Chemistry 2021; 27:15074-15079. [PMID: 34423877 PMCID: PMC8596823 DOI: 10.1002/chem.202102542] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Indexed: 12/03/2022]
Abstract
Au2+ is a simple but crucial model system for understanding the diverse catalytic activity of gold. While the Au2+ ground state (X2Σg+) is understood reasonably well from mass spectrometry and computations, no spectroscopic information is available for its first excited state (A2Σu+). Herein, we present the vibrationally resolved electronic spectrum of this state for cold Ar‐tagged Au2+ cations. This exceptionally low‐lying and well isolated A2Σ(u)+←X2Σ(g)+ transition occurs in the near‐infrared range. The observed band origin (5738 cm−1, 1742.9 nm, 0.711 eV) and harmonic Au−Au and Au−Ar stretch frequencies (201 and 133 cm−1) agree surprisingly well with those predicted by standard time‐dependent density functional theory calculations. The linearly bonded Ar tag has little impact on either the geometric or electronic structure of Au2+, because the Au2+⋅⋅⋅Ar bond (∼0.4 eV) is much weaker than the Au−Au bond (∼2 eV). As a result of 6 s←5d excitation of an electron from the antibonding σu* orbital (HOMO‐1) into the bonding σg orbital (SOMO), the Au−Au bond contracts substantially (by 0.1 Å).
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Affiliation(s)
- Marko Förstel
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Kai Pollow
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Taarna Studemund
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
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6
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Green AE, Gentleman AS, Schöllkopf W, Fielicke A, Mackenzie SR. Atomic Cluster Au_{10}^{+} Is a Strong Broadband Midinfrared Chromophore. PHYSICAL REVIEW LETTERS 2021; 127:033002. [PMID: 34328766 DOI: 10.1103/physrevlett.127.033002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/30/2021] [Accepted: 05/25/2021] [Indexed: 06/13/2023]
Abstract
We report an intense broadband midinfrared absorption band in the Au_{10}^{+} cluster in a region in which only molecular vibrations would normally be expected. Observed in the infrared multiple photon dissociation spectra of Au_{10}Ar^{+}, Au_{10}(N_{2}O)^{+}, and Au_{10}(OCS)^{+}, the smooth feature stretches 700-3400 cm^{-1} (λ=14-2.9 μm). Calculations confirm unusually low-energy allowed electronic excitations consistent with the observed spectra. In Au_{10}(OCS)^{+}, IR absorption throughout the band drives OCS decomposition resulting in CO loss, providing an alternative method of bond activation or breaking.
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Affiliation(s)
- Alice E Green
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Alexander S Gentleman
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Wieland Schöllkopf
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
| | - André Fielicke
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
- Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Stuart R Mackenzie
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, United Kingdom
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7
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Förstel M, Pollow KM, Saroukh K, Najib EA, Mitric R, Dopfer O. The Optical Spectrum of Au
2
+. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marko Förstel
- Technische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
| | - Kai Mario Pollow
- Technische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
| | - Karim Saroukh
- Technische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
| | - Este Ainun Najib
- Technische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
| | - Roland Mitric
- Julius-Maximilians-Universität Würzburg Institut für Physikalische und Theoretische Chemie Emil-Fischer-Str. 42 97074 Würzburg Germany
| | - Otto Dopfer
- Technische Universität Berlin Hardenbergstr. 36 10623 Berlin Germany
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8
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Förstel M, Pollow KM, Saroukh K, Najib EA, Mitric R, Dopfer O. The Optical Spectrum of Au 2. Angew Chem Int Ed Engl 2020; 59:21403-21408. [PMID: 32888257 PMCID: PMC7756737 DOI: 10.1002/anie.202011337] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Indexed: 11/08/2022]
Abstract
The electronic structure of the Au2 + cation is essential for understanding its catalytic activity. We present the optical spectrum of mass-selected Au2 + measured via photodissociation spectroscopy. Two vibrationally resolved band systems are observed in the 290-450 nm range (at ca. 440 and ca. 325 nm), which both exhibit rather irregular structure indicative of strong vibronic and spin-orbit coupling. The experimental spectra are compared to high-level quantum-chemical calculations at the CASSCF-MRCI level including spin-orbit coupling. The results demonstrate that the understanding of the electronic structure of this simple, seemingly H2 + -like diatomic molecular ion strictly requires multireference and relativistic treatment including spin-orbit effects. The calculations reveal that multiple electronic states contribute to each respective band system. It is shown that popular DFT methods completely fail to describe the complex vibronic pattern of this fundamental diatomic cation.
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Affiliation(s)
- Marko Förstel
- Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Kai Mario Pollow
- Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Karim Saroukh
- Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Este Ainun Najib
- Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
| | - Roland Mitric
- Julius-Maximilians-Universität Würzburg, Institut für Physikalische und Theoretische Chemie, Emil-Fischer-Str. 42, 97074, Würzburg, Germany
| | - Otto Dopfer
- Technische Universität Berlin, Hardenbergstr. 36, 10623, Berlin, Germany
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9
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Lehr A, Jäger M, Gleditzsch M, Rivic F, Schäfer R. Optical Absorption of Atomically-Precise Sn 14 Nanoclusters: The Antagonistic Interplay of Ligand Stabilization, Molecular Symmetry, and Solvatochromism. J Phys Chem Lett 2020; 11:7827-7831. [PMID: 32822196 DOI: 10.1021/acs.jpclett.0c02183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The synthesis of atomically precise clusters is nowadays well established. The study of isolated clusters in the gas phase has also become an approved field of research. Although both approaches examine the same research objects, namely nanoclusters, little is known about to what extent results from gas phase studies can be transferred to colloidal systems and vice versa. In particular, it is not yet sufficiently understood how ligands influence the geometric and electronic structure of clusters from an experimental point of view. By comparing a ligand-stabilized tin nanocluster in solution with an isolated species in the gas phase and considering different geometric arrangements with the same number of tin atoms, the impacts of ligand stabilization, molecular symmetry, and solvatochromism on the optical behavior are thoroughly worked out for the first time.
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Affiliation(s)
- Andreas Lehr
- Eduard-Zintl-Institut, Technical University of Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Marc Jäger
- Eduard-Zintl-Institut, Technical University of Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Martin Gleditzsch
- Eduard-Zintl-Institut, Technical University of Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Filip Rivic
- Eduard-Zintl-Institut, Technical University of Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Rolf Schäfer
- Eduard-Zintl-Institut, Technical University of Darmstadt, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
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10
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Förstel M, Schewe W, Dopfer O. Optical Spectroscopy of the Au 4
+
Cluster: The Resolved Vibronic Structure Indicates an Unexpected Isomer. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201813094] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Marko Förstel
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
| | - Wolfgang Schewe
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
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11
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Förstel M, Schewe W, Dopfer O. Optical Spectroscopy of the Au4
+
Cluster: The Resolved Vibronic Structure Indicates an Unexpected Isomer. Angew Chem Int Ed Engl 2019; 58:3356-3360. [DOI: 10.1002/anie.201813094] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/14/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Marko Förstel
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
| | - Wolfgang Schewe
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
| | - Otto Dopfer
- Institut für Optik und Atomare Physik; Technische Universität Berlin; Hardenbergstr. 36 10623 Berlin Germany
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12
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Jäger M, Shayeghi A, Klippenstein V, Johnston RL, Schäfer R. Chemical bonding in initial building blocks of semiconductors: Geometrical structures and optical absorption spectra of isolated CdSe2+ and Cd2Se2+ species. J Chem Phys 2018; 149:244308. [DOI: 10.1063/1.5066414] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Marc Jäger
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Armin Shayeghi
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
- Vienna Center for Quantum Science and Technology, Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Viktor Klippenstein
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
| | - Roy L. Johnston
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Rolf Schäfer
- Technische Universität Darmstadt, Eduard-Zintl-Institut, Alarich-Weiss-Straße 8, 64287 Darmstadt, Germany
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