1
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Najeeb PK, Stockett MH, Anderson EK, Kristiansson MK, Reinhed P, Simonsson A, Rosén S, Thomas RD, Chartkunchand KC, Gnaser H, Golser R, Hanstorp D, Larson Å, Cederquist H, Schmidt HT, Zettergren H. Stability and Cooling of the C_{7}^{2-} Dianion. PHYSICAL REVIEW LETTERS 2023; 131:113003. [PMID: 37774298 DOI: 10.1103/physrevlett.131.113003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 06/26/2023] [Accepted: 08/12/2023] [Indexed: 10/01/2023]
Abstract
We have studied the stability of the smallest long-lived all carbon molecular dianion (C_{7}^{2-}) in new time domains and with a single ion at a time using a cryogenic electrostatic ion-beam storage ring. We observe spontaneous electron emission from internally excited dianions on millisecond timescales and monitor the survival of single colder C_{7}^{2-} molecules on much longer timescales. We find that their intrinsic lifetime exceeds several minutes-6 orders of magnitude longer than established from earlier experiments on C_{7}^{2-}. This is consistent with our calculations of vertical electron detachment energies predicting one inherently stable isomer and one isomer which is stable or effectively stable behind a large Coulomb barrier for C_{7}^{2-}→C_{7}^{-}+e^{-} separation.
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Affiliation(s)
- P K Najeeb
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - M H Stockett
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - E K Anderson
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - M K Kristiansson
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - P Reinhed
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - A Simonsson
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - S Rosén
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - R D Thomas
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - K C Chartkunchand
- AMO Physics Laboratory, RIKEN Advanced Science Institute, Saitama 351-0198, Japan
| | - H Gnaser
- Institute for Isotope Physics, University of Vienna, Vienna A-1090, Austria
| | - R Golser
- Institute for Isotope Physics, University of Vienna, Vienna A-1090, Austria
| | - D Hanstorp
- Department of Physics, University of Gothenburg, SE-412 96 Gothenburg, Sweden
| | - Å Larson
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - H Cederquist
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - H T Schmidt
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
| | - H Zettergren
- Department of Physics, Stockholm University, AlbaNova, Stockholm SE-106 91, Sweden
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2
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Gnaser H, Martschini M, Leimbach D, Karls J, Hanstorp D, Indrajith S, Ji M, Martini P, Simonsson A, Zettergren H, Schmidt HT, Golser R. Spontaneous and photo-induced decay processes of WF 5 - and HfF 5 - molecular anions in a cryogenic storage ring. J Chem Phys 2022; 157:044304. [PMID: 35922356 DOI: 10.1063/5.0097896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Spontaneous and photo-induced decay processes of HfF5 - and WF5 - molecular anions were investigated in the Double ElectroStatic Ion Ring ExpEriment (DESIREE). The observation of these reactions over long time scales (several tens of ms) was possible due to the cryogenic temperatures (13 K) and the extremely low residual gas pressure (∼10-14 mbar) of DESIREE. For photo-induced reactions, laser wavelengths in the range 240 to 450 nm were employed. Both anion species were found to undergo spontaneous decay via electron detachment or fragmentation. After some ms, radiative cooling processes were observed to lower the probability for further decay through these processes. Photo-induced reactions indicate the existence of an energy threshold for WF5 - anions at about 3.5 eV, above which the neutralization yield increases strongly. By contrast, HfF5 - ions exhibit essentially no enhanced production of neutrals upon photon interaction, even for the highest photon energy used in this experiment (∼5.2 eV). This suppression will be highly beneficial for the efficient detection, in accelerator mass spectrometry, of the extremely rare isotope 182Hf using the 182HfF5 - anion while effectively reducing the interfering stable isobar 182W in the analyte ion 182WF5 -. The radionuclide 182Hf is of great relevance in astrophysical environments as it constitutes a potential candidate to study the events of nucleosynthesis that may have taken place in the vicinity of the solar system several million years ago.
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Affiliation(s)
- Hubert Gnaser
- University of Vienna, Faculty of Physics, Isotope Physics - VERA Laboratory, A-1090 Wien, Austria
| | - Martin Martschini
- University of Vienna, Faculty of Physics, Isotope Physics - VERA Laboratory, A-1090 Wien, Austria
| | - David Leimbach
- Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden
| | - Julia Karls
- Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden
| | - Dag Hanstorp
- Department of Physics, University of Gothenburg, SE-41296 Gothenburg, Sweden
| | | | - Mingchao Ji
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Paul Martini
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Ansgar Simonsson
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | | | - Henning T Schmidt
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
| | - Robin Golser
- University of Vienna, Faculty of Physics, Isotope Physics - VERA Laboratory, A-1090 Wien, Austria
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3
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Czichy M, Colombo A, Wagner P, Janasik P, Dragonetti C, Raja R, Officer DL, Wang L. Exohedral Functionalization of Fullerene by Substituents Controlling of Molecular Organization for Spontaneous C 60 Dimerization in Liquid Crystal Solutions and in a Bulk Controlled by a Potential. Polymers (Basel) 2021; 13:polym13162816. [PMID: 34451354 PMCID: PMC8401323 DOI: 10.3390/polym13162816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/13/2021] [Accepted: 08/19/2021] [Indexed: 11/21/2022] Open
Abstract
A study was carried out on the possibility of orderly and spontaneous dimerization at room temperature of C60 cages in fullerene liquid crystal fullerene dyads (R-C60). For this purpose, dyads with a structural elements feature supporting π-stacking and Van der Waals interactions were tested, due to the presence of terthiophene donors linked through an α-position or dodecyloxy chains. In addition, this possibility was also tested and compared to dyads with shorter substituents and the pristine C60. Research has shown that only in dyads with the features of liquid crystals, π-dimerization of C60 units occurs, which was verified by electrochemical and spectroelectrochemical (ESR) measurements. Cyclic voltammetry and differential voltammetry studies reveal π-dimerization in liquid crystal dyad solution even without the possibility of previous polymerization (cathodic or anodic) under conditions in the absence of irradiation and without the availability of reaction initiators, and even with the use of preliminary homogenization. These dyads undergo six sequential, one-electron reductions of π-dimer (R-C60···C60-R), where two electrons are added successively to each of the two fullerene cages and first form two radical anion system (R-C60)•−(R-C60)•− without pairing with the characteristics of two doublets. Similarly, the second reductions of π-dimer occur at potentials that are close to the reduction potential for the conversion to a system of two triplet dianions (R-C60)2−(R-C60)2−. Electron paramagnetic resonance spectra indicate a significant interaction between C60 cages. Interestingly, the strength of intermolecular bonds is so significant that it can overcome Coulombic repulsion, even with such highly charged particles as dianions and trianions. Such behavior has been revealed and studied so far only in covalently bonded C60 dimers.
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Affiliation(s)
- Malgorzata Czichy
- Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland;
- Correspondence:
| | - Alessia Colombo
- Department of Chemistry, University of Milan, UdR dell’INSTM, Via Golgi 19, 20133 Milan, Italy; (A.C.); (C.D.)
| | - Pawel Wagner
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia; (P.W.); (D.L.O.)
| | - Patryk Janasik
- Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland;
| | - Claudia Dragonetti
- Department of Chemistry, University of Milan, UdR dell’INSTM, Via Golgi 19, 20133 Milan, Italy; (A.C.); (C.D.)
| | - Rathinam Raja
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan; (R.R.); (L.W.)
| | - David L. Officer
- ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia; (P.W.); (D.L.O.)
| | - Leeyih Wang
- Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan; (R.R.); (L.W.)
- Institute of Polymer Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
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4
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Martini P, Goulart M, Kranabetter L, Gitzl N, Rasul B, Scheier P, Echt O. Charged Clusters of C 60 and Au or Cu: Evidence for Stable Sizes and Specific Dissociation Channels. J Phys Chem A 2019; 123:4599-4608. [PMID: 31062979 PMCID: PMC6545602 DOI: 10.1021/acs.jpca.9b02768] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Revised: 04/29/2019] [Indexed: 12/02/2022]
Abstract
We have doped helium nanodroplets with C60 and either gold or copper. Positively or negatively charged (C60) mM n± ions (M = Au or Cu) containing up to ≈10 fullerenes and ≈20 metal atoms are formed by electron ionization. The abundance distributions extracted from high-resolution mass spectra reveal several local anomalies. The sizes of the four most stable (C60) mAu n± ions identified in previous calculations for small values of m and n ( m ≤ 2 and n ≤ 2, or m = 1 and n = 3) agree with local maxima in the abundance distributions. Our data suggest the existence of several other relatively stable ions including (C60)2Au3± and (C60)3Au4-. Another feature, namely the absence of bare (C60)2±, confirms the prediction that (C60)2M± dissociates by loss of C60± rather than loss of M. The experimental data also reveal the preference for loss of (charged or neutral) C60 over loss of a metal atom from some larger species such as (C60)3M3+. In contrast to these similarities between Au and Cu, the abundance distributions of (C60)3Au n- and (C60)3Cu n- are markedly different. In this discussion, we emphasize the similarities and differences between anions and cations, and between gold and copper. Also noteworthy is the observation of dianions (C60) mAu n2- for m = 2, 4, and 6.
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Affiliation(s)
- Paul Martini
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Marcelo Goulart
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Lorenz Kranabetter
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Norbert Gitzl
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Bilal Rasul
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
- Department
of Physics, University of Sargodha, 40100 Sargodha, Pakistan
| | - Paul Scheier
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Olof Echt
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
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5
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Wang Y, Díaz-Tendero S, Alcamí M, Martín F. Aromaticity, Coulomb repulsion, π delocalization or strain: who is who in endohedral metallofullerene stability? Phys Chem Chem Phys 2019; 21:124-131. [DOI: 10.1039/c8cp06707d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Three different models for endohedral metallofullerene structure prediction are compared, revealing the physical origin of the stability of these compounds.
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Affiliation(s)
- Yang Wang
- School of Chemistry and Chemical Engineering
- Yangzhou University
- Yangzhou
- China
- Departamento de Química
| | - Sergio Díaz-Tendero
- Departamento de Química
- Módulo 13
- Universidad Autónoma de Madrid
- 28049 Madrid
- Spain
| | - Manuel Alcamí
- Departamento de Química
- Módulo 13
- Universidad Autónoma de Madrid
- 28049 Madrid
- Spain
| | - Fernando Martín
- Departamento de Química
- Módulo 13
- Universidad Autónoma de Madrid
- 28049 Madrid
- Spain
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6
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Weis P, Hennrich F, Fischer R, Schneider EK, Neumaier M, Kappes MM. Probing the structure of giant fullerenes by high resolution trapped ion mobility spectrometry. Phys Chem Chem Phys 2019; 21:18877-18892. [DOI: 10.1039/c9cp03326b] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We present high-resolution trapped ion mobility spectrometry (TIMS) measurements for fullerene ions in molecular nitrogen.
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Affiliation(s)
- Patrick Weis
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76049 Karlsruhe
- Germany
| | - Frank Hennrich
- Institute of Nanotechnology
- Karlsruhe Institute of Technology (KIT)
- 76021 Karlsruhe
- Germany
| | - Regina Fischer
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76049 Karlsruhe
- Germany
| | - Erik K. Schneider
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76049 Karlsruhe
- Germany
| | - Marco Neumaier
- Institute of Nanotechnology
- Karlsruhe Institute of Technology (KIT)
- 76021 Karlsruhe
- Germany
| | - Manfred M. Kappes
- Institute of Physical Chemistry
- Karlsruhe Institute of Technology (KIT)
- 76049 Karlsruhe
- Germany
- Institute of Nanotechnology
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7
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Chartkunchand KC, Stockett MH, Anderson EK, Eklund G, Kristiansson MK, Kamińska M, de Ruette N, Blom M, Björkhage M, Källberg A, Löfgren P, Reinhed P, Rosén S, Simonsson A, Zettergren H, Schmidt HT, Cederquist H. Dianion diagnostics in DESIREE: High-sensitivity detection of C n2- from a sputter ion source. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:033112. [PMID: 29604753 DOI: 10.1063/1.5010077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A sputter ion source with a solid graphite target has been used to produce dianions with a focus on carbon cluster dianions, Cn2-, with n = 7-24. Singly and doubly charged anions from the source were accelerated together to kinetic energies of 10 keV per atomic unit of charge and injected into one of the cryogenic (13 K) ion-beam storage rings of the Double ElectroStatic Ion Ring Experiment facility at Stockholm University. Spontaneous decay of internally hot Cn2- dianions injected into the ring yielded Cn- anions with kinetic energies of 20 keV, which were counted with a microchannel plate detector. Mass spectra produced by scanning the magnetic field of a 90° analyzing magnet on the ion injection line reflect the production of internally hot C72- - C242- dianions with lifetimes in the range of tens of microseconds to milliseconds. In spite of the high sensitivity of this method, no conclusive evidence of C62- was found while there was a clear C72- signal with the expected isotopic distribution. This is consistent with earlier experimental studies and with theoretical predictions. An upper limit is deduced for a C62- signal that is two orders-of-magnitude smaller than that for C72-. In addition, CnO2- and CnCu2- dianions were detected.
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Affiliation(s)
- K C Chartkunchand
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - M H Stockett
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - E K Anderson
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - G Eklund
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - M K Kristiansson
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - M Kamińska
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - N de Ruette
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - M Blom
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - M Björkhage
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - A Källberg
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - P Löfgren
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - P Reinhed
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - S Rosén
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - A Simonsson
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - H Zettergren
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - H T Schmidt
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
| | - H Cederquist
- Department of Physics, Stockholm University, AlbaNova, SE-106 91 Stockholm, Sweden
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8
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Wang Y, Díaz-Tendero S, Alcamí M, Martín F. Topology-Based Approach to Predict Relative Stabilities of Charged and Functionalized Fullerenes. J Chem Theory Comput 2018; 14:1791-1810. [DOI: 10.1021/acs.jctc.7b01048] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yang Wang
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Sergio Díaz-Tendero
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Manuel Alcamí
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Institute for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
| | - Fernando Martín
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA-Nanociencia), 28049 Madrid, Spain
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9
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Concina B, Lépine F, Bordas C. A detailed-balance model for thermionic emission from polyanions: The case of fullerene dianions. J Chem Phys 2017; 146:224311. [PMID: 29166075 DOI: 10.1063/1.4985609] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A detailed-balance model for thermionic emission from polyanions has been developed and applied to fullerene dianions. The specificity of this delayed decay process is electron tunneling through the repulsive Coulomb barrier (RCB). An analytical expression of the RCB is derived from electrostatic modeling of the fullerene cage. The reverse process, namely, electron attachment to the singly charged anion, is described by a hard sphere cross section weighted by the Wentzel-Kramers-Brillouin tunneling probability. This simple expression leads to a very good agreement with a measured time-resolved kinetic energy distribution of C842-. Electron binding energy is reduced when the fullerene cage size decreases, leading to an almost zero one for C702- and a negative one for C602-. Extension of the model to these systems of interest is discussed, and model outputs are compared with the experimental data from the literature.
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Affiliation(s)
- Bruno Concina
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - Franck Lépine
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - Christian Bordas
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
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10
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Wang Y, Díaz-Tendero S, Alcamí M, Martín F. Cage connectivity and frontier π orbitals govern the relative stability of charged fullerene isomers. Nat Chem 2015; 7:927-34. [DOI: 10.1038/nchem.2363] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/02/2015] [Indexed: 01/27/2023]
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11
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Mauracher A, Daxner M, Huber SE, Postler J, Renzler M, Denifl S, Scheier P, Ellis AM. The interaction of He− with fullerenes. J Chem Phys 2015; 142:104306. [DOI: 10.1063/1.4913956] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Andreas Mauracher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Matthias Daxner
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Stefan E. Huber
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Johannes Postler
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Michael Renzler
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Stephan Denifl
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Paul Scheier
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria
| | - Andrew M. Ellis
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
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12
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Mauracher A, Daxner M, Huber SE, Postler J, Renzler M, Denifl S, Scheier P, Ellis AM. Formation of Dianions in Helium Nanodroplets. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201408172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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13
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Mauracher A, Daxner M, Huber SE, Postler J, Renzler M, Denifl S, Scheier P, Ellis AM. Formation of dianions in helium nanodroplets. Angew Chem Int Ed Engl 2014; 53:13794-7. [PMID: 25296629 DOI: 10.1002/anie.201408172] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Indexed: 11/05/2022]
Abstract
The formation of dianions in helium nanodroplets is reported for the first time. The fullerene cluster dianions (C60)n(2-) and (C70)n(2-) were observed by mass spectrometry for n≥5 when helium droplets containing the appropriate fullerene were subjected to electron impact at approximately 22 eV. A new mechanism for dianion formation is described, which involves a two-electron transfer from the metastable He(-) ion. As well as the prospect of studying other dianions at low temperature using helium nanodroplets, this work opens up the possibility of a wider investigation of the chemistry of He(-), a new electron-donating reagent.
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Affiliation(s)
- Andreas Mauracher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, 6020 Innsbruck (Austria)
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14
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Schmidt HT, Thomas RD, Gatchell M, Rosén S, Reinhed P, Löfgren P, Brännholm L, Blom M, Björkhage M, Bäckström E, Alexander JD, Leontein S, Hanstorp D, Zettergren H, Liljeby L, Källberg A, Simonsson A, Hellberg F, Mannervik S, Larsson M, Geppert WD, Rensfelt KG, Danared H, Paál A, Masuda M, Halldén P, Andler G, Stockett MH, Chen T, Källersjö G, Weimer J, Hansen K, Hartman H, Cederquist H. First storage of ion beams in the Double Electrostatic Ion-Ring Experiment: DESIREE. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:055115. [PMID: 23742597 DOI: 10.1063/1.4807702] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report on the first storage of ion beams in the Double ElectroStatic Ion Ring ExpEriment, DESIREE, at Stockholm University. We have produced beams of atomic carbon anions and small carbon anion molecules (C(n)(-), n = 1, 2, 3, 4) in a sputter ion source. The ion beams were accelerated to 10 keV kinetic energy and stored in an electrostatic ion storage ring enclosed in a vacuum chamber at 13 K. For 10 keV C2 (-) molecular anions we measure the residual-gas limited beam storage lifetime to be 448 s ± 18 s with two independent detector systems. Using the measured storage lifetimes we estimate that the residual gas pressure is in the 10(-14) mbar range. When high current ion beams are injected, the number of stored particles does not follow a single exponential decay law as would be expected for stored particles lost solely due to electron detachment in collision with the residual-gas. Instead, we observe a faster initial decay rate, which we ascribe to the effect of the space charge of the ion beam on the storage capacity.
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Affiliation(s)
- H T Schmidt
- Department of Physics, Stockholm University, SE-10691 Stockholm, Sweden
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15
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Thomas RD, Schmidt HT, Andler G, Björkhage M, Blom M, Brännholm L, Bäckström E, Danared H, Das S, Haag N, Halldén P, Hellberg F, Holm AIS, Johansson HAB, Källberg A, Källersjö G, Larsson M, Leontein S, Liljeby L, Löfgren P, Malm B, Mannervik S, Masuda M, Misra D, Orbán A, Paál A, Reinhed P, Rensfelt KG, Rosén S, Schmidt K, Seitz F, Simonsson A, Weimer J, Zettergren H, Cederquist H. The double electrostatic ion ring experiment: a unique cryogenic electrostatic storage ring for merged ion-beams studies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2011; 82:065112. [PMID: 21721735 DOI: 10.1063/1.3602928] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We describe the design of a novel type of storage device currently under construction at Stockholm University, Sweden, using purely electrostatic focussing and deflection elements, in which ion beams of opposite charges are confined under extreme high vacuum cryogenic conditions in separate "rings" and merged over a common straight section. The construction of this double electrostatic ion ring experiment uniquely allows for studies of interactions between cations and anions at low and well-defined internal temperatures and centre-of-mass collision energies down to about 10 K and 10 meV, respectively. Position sensitive multi-hit detector systems have been extensively tested and proven to work in cryogenic environments and these will be used to measure correlations between reaction products in, for example, electron-transfer processes. The technical advantages of using purely electrostatic ion storage devices over magnetic ones are many, but the most relevant are: electrostatic elements which are more compact and easier to construct; remanent fields, hysteresis, and eddy-currents, which are of concern in magnetic devices, are no longer relevant; and electrical fields required to control the orbit of the ions are not only much easier to create and control than the corresponding magnetic fields, they also set no upper mass limit on the ions that can be stored. These technical differences are a boon to new areas of fundamental experimental research, not only in atomic and molecular physics but also in the boundaries of these fields with chemistry and biology. For examples, studies of interactions with internally cold molecular ions will be particular useful for applications in astrophysics, while studies of solvated ionic clusters will be of relevance to aeronomy and biology.
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Affiliation(s)
- R D Thomas
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden.
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Abstract
I investigated the structural and electronic properties of both Na(n)C(60) and Li(n)C(60) (n < or = 12) clusters in the framework of density-functional theory. The behavior of the alkali atoms over the C(60) surface is analyzed. The hypotheses for either an homogeneous coating of the C(60) surface by the alkali atoms or the growth of an alkali droplet not wetting the fullerene surface are discussed. Lithium atoms are found to coat homogeneously the fullerene on the C(60) surface via pentagonal sites, contrary to sodium atoms, which prefer to form 4-atom islands on the surface. The charge transfer, the energetics, and the dipole moments are discussed in relation with available results. The adsorption of alkali atoms on the C(60) surface considerably enhances the capacity of C(60) to accept electrons. The arrangement of lithium atoms seems more favorable for the hydrogen storage than that of sodium atoms.
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Affiliation(s)
- Franck Rabilloud
- Université Lyon 1, Villeurbanne, CNRS, UMR5579, LASIM, F-69622, Lyon, France.
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Hampe O, Neumaier M, Boese AD, Lemaire J, Niedner-Schatteburg G, Kappes MM. Infrared multiphoton electron detachment spectroscopy of C762−. J Chem Phys 2009. [DOI: 10.1063/1.3224130] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Kadhane U, Andersen JU, Bonderup E, Concina B, Hvelplund P, Suhr Kirketerp MB, Liu B, Nielsen SB, Panja S, Rangama J, Støchkel K, Tomita S, Zettergren H, Hansen K, Sundén AEK, Canton SE, Echt O, Forster JS. Near-infrared photoabsorption by C60 dianions in a storage ring. J Chem Phys 2009; 131:014301. [PMID: 19586099 DOI: 10.1063/1.3149775] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
We present a detailed study of the electronic structure and the stability of C(60) dianions in the gas phase. Monoanions were extracted from a plasma source and converted to dianions by electron transfer in a Na vapor cell. The dianions were then stored in an electrostatic ring, and their near-infrared absorption spectrum was measured by observation of laser induced electron detachment. From the time dependence of the detachment after photon absorption, we conclude that the reaction has contributions from both direct electron tunneling to the continuum and vibrationally assisted tunneling after internal conversion. This implies that the height of the Coulomb barrier confining the attached electrons is at least approximately 1.5 eV. For C(60)(2-) ions in solution electron spin resonance measurements have indicated a singlet ground state, and from the similarity of the absorption spectra we conclude that also the ground state of isolated C(60)(2-) ions is singlet. The observed spectrum corresponds to an electronic transition from a t(1u) lowest unoccupied molecular orbital (LUMO) of C(60) to the t(1g) LUMO+1 level. The electronic levels of the dianion are split due to Jahn-Teller coupling to quadrupole deformations of the molecule, and a main absorption band at 10,723 cm(-1) corresponds to a transition between the Jahn-Teller ground states. Also transitions from pseudorotational states with 200 cm(-1) and (probably) 420 cm(-1) excitation are observed. We argue that a very broad absorption band from about 11,500 cm(-1) to 13,500 cm(-1) consists of transitions to so-called cone states, which are Jahn-Teller states on a higher potential-energy surface, stabilized by a pseudorotational angular momentum barrier. A previously observed, high-lying absorption band for C(60)(-) may also be a transition to a cone state.
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Affiliation(s)
- U Kadhane
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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19
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Affiliation(s)
- Xue-Bin Wang
- Department of Physics, Washington State University, Richland, Washington 99354, and Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352;
| | - Lai-Sheng Wang
- Department of Physics, Washington State University, Richland, Washington 99354, and Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99352;
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20
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Thomas RD. When electrons meet molecular ions and what happens next: dissociative recombination from interstellar molecular clouds to internal combustion engines. MASS SPECTROMETRY REVIEWS 2008; 27:485-530. [PMID: 18618616 DOI: 10.1002/mas.20169] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The interaction of matter with its environment is the driving force behind the evolution of 99% of the observed matter in the universe. The majority of the visible universe exists in a state of weak ionization, the so called fourth state of matter: plasma. Plasmas are ubiquitous, from those occurring naturally; interstellar molecular clouds, cometary comae, circumstellar shells, to those which are anthropic in origin; flames, combustion engines and fusion reactors. The evolution of these plasmas is driven by the interaction of the plasma constituents, the ions, and the electrons. One of the most important subsets of these reactions is electron-molecular ion recombination. This process is significant for two very important reasons. It is an ionization reducing reaction, removing two ionised species and producing neutral products. Furthermore, these products may themselves be reactive radical species which can then further drive the evolution of the plasma. The rate at which the electron reacts with the ion depends on many parameters, for examples the collision energy, the internal energy of the ion, and the structure of the ion itself. Measuring these properties together with the manner in which the system breaks up is therefore critical if the evolution of the environment is to be understood at all. Several techniques have been developed to study just such reactions to obtain the necessary information on the parameters. In this paper the focus will be on one the most recently developed of these, the Ion Storage Ring, together with the detection tools and techniques used to extract the necessary information from the reaction.
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Affiliation(s)
- Richard D Thomas
- Department of Physics, Albanova University Centre, Stockholm University, S106 91 Stockholm, Sweden.
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Goto M, Togawa M, Jinno S, Takao T, Matsumoto J, Shiromaru H, Achiba Y, Tanuma H, Azuma T. Absorption spectra of zinc phthalocyanine anions under radiative cooling. Chem Phys Lett 2008. [DOI: 10.1016/j.cplett.2008.05.091] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Bernard J, Montagne G, Brédy R, Terpend-Ordacière B, Bourgey A, Kerleroux M, Chen L, Schmidt HT, Cederquist H, Martin S. A "tabletop" electrostatic ion storage ring: Mini-Ring. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:075109. [PMID: 18681736 DOI: 10.1063/1.2957609] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We report on the design, construction, and commissioning of a novel electrostatic ion storage ring of small dimensions--in the following referred to as "Mini-Ring." Mini-Ring consists of four horizontal parallel-plate deflectors and two conical electrostatic mirrors. Ions are injected through the two deflectors on the injection side and off axis with respect to the conical mirrors which face each other. The first injection deflector, originally at zero voltage, is switched to its set value such that the ions after one turn follow stable trajectories of lengths of roughly 30 cm. This design reduces the number of electrodes necessary to guide the ion beam through the ring in stable orbits. The six elements (deflectors and mirrors) are placed on a common grounded plate--the tabletop. Here, we present the design, ion trajectory simulations, and results of the first test experiments demonstrating the successful room-temperature operation of Mini-Ring at background pressures of 10(-6) - 10(-7) mbar.
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Affiliation(s)
- J Bernard
- Universite Lyon 1, CNRS, LASIM UMR 5579, bât. A. Kastler, 43 Bvd. du 11 novembre 1918, F-69622 Villeurbanne, France
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23
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Concina B, Neumaier M, Hampe O, Kappes MM. Electron emission from laser-heated fullerene dianions: Probing the repulsive Coulomb barrier. J Chem Phys 2008; 128:134306. [DOI: 10.1063/1.2842145] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Støchkel K, Kadhane U, Andersen JU, Holm AIS, Hvelplund P, Kirketerp MBS, Larsen MK, Lykkegaard MK, Nielsen SB, Panja S, Zettergren H. A new technique for time-resolved daughter ion mass spectrometry on the microsecond to millisecond time scale using an electrostatic ion storage ring. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:023107. [PMID: 18315283 DOI: 10.1063/1.2884121] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A new method for time-resolved daughter ion mass spectrometry is presented, based on the electrostatic ion storage ring in Aarhus, ELISA. Ions with high internal energy, e.g., as a result of photoexcitation, dissociate and the yield of neutrals is monitored as a function of time. This gives information on lifetimes in the microsecond to millisecond time range but no information on the fragment masses. To determine the dissociation channels, we have introduced pulsed supplies with switching times of a few microseconds. This allows rapid switching from storage of parent ions to storage of daughter ions, which are dumped into a detector after a number of revolutions in the ring. A fragment mass spectrum is obtained by monitoring the daughter ion signal as a function of the ring voltages. This technique allows identification of the dissociation channels and determination of the time dependent competition between these channels.
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Affiliation(s)
- Kristian Støchkel
- Institute for Storage Ring Facilities, University of Aarhus, Ny Munkegade, DK-8000 Aarhus C, Denmark
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Panja S, Kadhane U, Andersen JU, Holm AIS, Hvelplund P, Kirketerp MBS, Nielsen SB, Stochkel K, Compton RN, Forster JS, Kilså K, Nielsen MB. Dianions of 7,7,8,8-tetracyano-p-quinodimethane and perfluorinated tetracyanoquinodimethane: Information on excited states from lifetime measurements in an electrostatic storage ring and optical absorption spectroscopy. J Chem Phys 2007; 127:124301. [PMID: 17902897 DOI: 10.1063/1.2771177] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We have developed an experimental technique that allows us to study the physics of short lived molecular dianions in the gas phase. It is based on the formation of monoanions via electrospray ionization, acceleration of these ions to keV energies, and subsequent electron capture in a sodium vapor cell. The dianions are stored in an electrostatic ion storage ring in which they circulate with revolution times on the order of 100 micros. This enables lifetime studies in a time regime covering five orders of magnitude, 10(-5)-1 s. We have produced dianions of 7,7,8,8-tetracyano-p-quinodimethane and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinodimethane (TCNQ-F(4)) and measured their lifetimes with respect to electron autodetachment. Our data indicate that most of the dianions were initially formed in electronically excited states in the electron transfer process. Two levels of excitation were identified by spectroscopy on the dianion of TCNQ-F(4), and the absorption spectrum was compared with spectra obtained from spectroelectrochemistry of TCNQ-F(4) in acetonitrile solution.
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Affiliation(s)
- Subhasis Panja
- Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark
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26
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Wang XB, Woo HK, Huang X, Kappes MM, Wang LS. Direct experimental probe of the on-site Coulomb repulsion in the doubly charged fullerene anion C70 2-. PHYSICAL REVIEW LETTERS 2006; 96:143002. [PMID: 16712068 DOI: 10.1103/physrevlett.96.143002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2006] [Indexed: 05/09/2023]
Abstract
Vibrationally resolved photoelectron spectra were obtained for cold C(70)- and C(70)2-. Accurate values for the first and second electron affinities (EA's) of C(70) were measured as 2.765 +/- 0.010 and 0.002 (+0.01/-0.03)eV, respectively, establishing that C(70)-2 is an electronically stable dianion in the gas phase. The difference between the first and second EA (2.75 eV) provides a direct experimental measure for the on-site Coulomb and exchange interactions between the two excess electrons in C(70)-2. Strong electron correlation effects were also observed between the two excess electrons in C(70)-2.
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Affiliation(s)
- Xue-Bin Wang
- Department of Physics, Washington State University, 2710 University Drive, Richland, WA 99354, USA
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