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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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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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Mane R, Mehrotra N, Maity DK, Gupta AK. On the formation of SFn (-) (n = 1-6) anions via a novel route and their properties. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1317-1327. [PMID: 26405793 DOI: 10.1002/rcm.7225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 05/07/2015] [Accepted: 05/07/2015] [Indexed: 06/05/2023]
Abstract
RATIONALE Sulfur hexafluoride (SF6 ) being a potential greenhouse gas, coupled with its numerous applications, makes the study of the formation and fragmentation of SF6 -based species important. The formation of SF6 -based anionic species has been studied using the gas feed-sputtering route and the mechanisms at play during the sputter-ejection of guest molecule-derived particles have also been probed. METHODS Studies of the formation of SFn (-) (n = 1-6) anions were conducted from various surfaces (metal and compound) that were subjected to Cs(+) ion sputtering in the presence of SF6 gas employing the gas feed-cesium sputter technique. The anions generated were mass analyzed using a double-focusing magnetic sector mass spectrometer. Quantum mechanical computations were performed to study the ground state structure and stability of neutral and negatively charged SFn (n = 1-6) systems applying density functional theory (DFT) and ab initio methods (MP2 and CC). RESULTS This technique readily generated (32) SFn (-) (n = 1-6) anions for all sizes of 'n' with practicable yields. Mass spectrometric measurements of the yield of sputter-ejected (32) SFn (-) (n = 1-6) anions reveal an oscillatory pattern as a function of 'n', with odd values of 'n' being relatively more abundant. The relative yield of (34) SFn (-) (n = 1-6) anions with respect to size was also measured albeit with low signal intensity. Also observed were F(-) , S(-) , F2 (-) , (33) SF5 (-) and (33) SF6 (-) anionic species. The relevant electron affinity and bond dissociation energy (BDE) values were also computed. CONCLUSIONS Gas-phase SFn (-) (n = 1-6) anions can be effectively generated by using the gas spray-cesium sputter technique. Both experimental measurements and calculations indicate the existence of odd-even oscillations in the stability and electronic structure of the SFn (n = 1-6) systems. The highest yield recorded was for the sputter-ejected SF5 (-) species and this may be attributed to its 'superhalogen' anionic character coupled with the relatively favorable F(0) fragmentation pathway of sputtered SF6 (-) . A signature pertaining to intact SF6 (-) anion ejection is also observed.
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Affiliation(s)
- Rupali Mane
- Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Nitin Mehrotra
- Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Dilip K Maity
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai, 400085, India
- Homi Bhabha National Institute, Training School Complex, Mumbai, 400094, India
| | - Anit K Gupta
- Nuclear Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
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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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Franzreb K, Sommerfeld T, Williams P. Small gas-phase dianions of Zn3O42−, Zn4O52−, CuZn2O42−, Si2GeO62−, Ti2O52−and Ti3O72−. Phys Chem Chem Phys 2007; 9:846-52. [PMID: 17287878 DOI: 10.1039/b615088h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We have searched for new species of small oxygen-containing gas-phase dianions produced in a secondary ion mass spectrometer by Cs+ ion bombardment of solid samples with simultaneous exposure of their surfaces to O2 gas. The targets were a pure zinc metal foil, a copper-contaminated zinc-based coin, two silicon-germanium samples (Si(1-x)Ge(x)(with x= 6.5% or 27%)) and a piece of titanium metal. The novel dianions Zn3O(4)(2-), Zn4O(5)(2-), CuZn2O(4)(2-), Si2GeO(6)(2-), Ti2O(5)(2-) and Ti3O(7)(2-) have been observed at half-integer m/z values in the negative ion mass spectra. The heptamer dianions Zn3O(4)(2-) and Ti2O(5)(2-) have been unambiguously identified by their isotopic abundances. Their flight times through the mass spectrometer are approximately 20 micros and approximately 17 micros, respectively. The geometrical structures of the two heptamer dianions Ti2O(5)(2-), and Zn3O(4)(2-) are investigated using ab initio methods, and the identified isomers are compared to those of the novel Ge2O(5)(2-) and the known Si2O(5)(2-) and Be3O(4)(2-) dianions.
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Affiliation(s)
- Klaus Franzreb
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287, USA
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Wang XB, Wang YL, Woo HK, Li J, Wu GS, Wang LS. Free tetra- and hexa-coordinated platinum-cyanide dianions, and : A combined photodetachment photoelectron spectroscopic and theoretical study. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2006.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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