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Rajput J, Garg D, Cassimi A, Fléchard X, Rangama J, Safvan CP. Addressing three-body fragmentation of methane dication using "native frames": Evidence of internal excitation in fragments. J Chem Phys 2023; 159:184303. [PMID: 37955322 DOI: 10.1063/5.0171881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/23/2023] [Indexed: 11/14/2023] Open
Abstract
The three body fragmentation of methane dication has been studied using the technique of cold target recoil ion momentum spectroscopy. The process is initiated by impact of energetic Ar9+ ions on neutral methane and the data is subsequently collected in coincidence with Ar8+ projectile. By analysing the dissociation channels leading to (H + H+ + CH2+) and (H + H2+ + CH+) fragments, it is concluded that these fragments are formed in a sequential manner via formation of molecular intermediates CH3+ and CH2+ respectively. It is shown that these molecular intermediates carry a few eVs as their internal energies, part of which is released when they emit an H-atom with the open possibility that the final detected fragments may still be internally excited. This was accomplished by analysing the two-steps of the sequential process in their own native frames. For a molecular system having three-dimensional structure, our results prove to be an ideal example to highlight the importance of using native frames for correct interpretation of the obtained results. Our results indicate that the dissociation of methane dication can be a major source of production of H-atoms in addition to H+ fragments with the probability of the two being of similar order.
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Affiliation(s)
- Jyoti Rajput
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - Diksha Garg
- Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - X Fléchard
- Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534, F-14000 Caen, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN-UNICAEN, Normandie Université, F-14050 Caen Cedex 04, France
| | - C P Safvan
- Inter-University Accelerator Centre, New Delhi 110067, India
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2
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Giglio E, Rangama J, Guillous S, Le Cornu T. Influence of the viscosity and charge mobility on the shape deformation of critically charged droplets. Phys Rev E 2020; 101:013105. [PMID: 32069655 DOI: 10.1103/physreve.101.013105] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Indexed: 11/07/2022]
Abstract
In this work, we model and simulate the shape evolution of critically charged droplets, from the initial spherical shape to the charge emission and back to the spherical shape. The shape deformation is described using the viscous correction for viscous potential flow model, which is a potential flow approximation of the Navier-Stokes equation for incompressible Newtonian fluids. The simulated shapes are compared to snapshots of experimentally observed drop deformations. We highlight the influence of the dimensionless viscosity and charge carrier mobility of the liquid on the shape evolution of droplets and discuss the observed trends. We give an explanation as to why the observed deformation pathways of positively and negatively charged pure water droplets differ and give a hint as to why negatively charged water droplets emit more charge during charge breakup than positively charged ones.
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Affiliation(s)
- E Giglio
- Centre de Recherche sur les Ions, les Matériaux et la Photonique, Université de Caen Normandie, ENSICAEN, CEA, CNRS, 14000 Caen, France
| | - J Rangama
- Centre de Recherche sur les Ions, les Matériaux et la Photonique, Université de Caen Normandie, ENSICAEN, CEA, CNRS, 14000 Caen, France
| | - S Guillous
- Centre de Recherche sur les Ions, les Matériaux et la Photonique, Université de Caen Normandie, ENSICAEN, CEA, CNRS, 14000 Caen, France
| | - T Le Cornu
- Centre de Recherche sur les Ions, les Matériaux et la Photonique, Université de Caen Normandie, ENSICAEN, CEA, CNRS, 14000 Caen, France
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3
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Guillous S, Bourin C, Ban D'Etat B, Benyagoub A, Cassimi A, Feierstein C, Gardés E, Giglio E, Girard S, Grygiel C, Houel A, Lebius H, Méry A, Monnet I, Ramillon JM, Rangama J, Ropars F, Verzeroli E, Viteau M, Delobbe A. A new setup for localized implantation and live-characterization of keV energy multiply charged ions at the nanoscale. Rev Sci Instrum 2016; 87:113901. [PMID: 27910696 DOI: 10.1063/1.4966675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An innovative experimental setup, PELIICAEN, allowing the modification of materials and the study of the effects induced by multiply charged ion beams at the nanoscale is presented. This ultra-high vacuum (below 5 × 10-10 mbar) apparatus is equipped with a focused ion beam column using multiply charged ions and a scanning electron microscope developed by Orsay Physics, as well as a scanning probe microscope. The dual beam approach coupled to the scanning probe microscope achieves nanometer scale in situ topological analysis of the surface modifications induced by the ion beams. Preliminary results using the different on-line characterization techniques to study the formation of nano-hillocks on silicon and mica substrates are presented to illustrate the performances of the setup.
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Affiliation(s)
- S Guillous
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - C Bourin
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - B Ban D'Etat
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Benyagoub
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Cassimi
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - C Feierstein
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - E Gardés
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - E Giglio
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - S Girard
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - C Grygiel
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Houel
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
| | - H Lebius
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - A Méry
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - I Monnet
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - J-M Ramillon
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - J Rangama
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - F Ropars
- CIMAP (CEA, CNRS, ENSICAEN, UNICAEN, Normandie University), Boulevard Henri Becquerel, BP 5133, Caen 14070 Cedex 5, France
| | - E Verzeroli
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
| | - M Viteau
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
| | - A Delobbe
- Orsay Physics (Tescan-Orsay Holding), 95 Avenue des Monts Auréliens, ZA Saint-Charles F-13710, Fuveau, France
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4
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Iskandar W, Matsumoto J, Leredde A, Fléchard X, Gervais B, Guillous S, Hennecart D, Méry A, Rangama J, Zhou CL, Shiromaru H, Cassimi A. Interatomic Coulombic decay as a new source of low energy electrons in slow ion-dimer collisions. Phys Rev Lett 2015; 114:033201. [PMID: 25658997 DOI: 10.1103/physrevlett.114.033201] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 06/04/2023]
Abstract
We provide the experimental evidence that the single electron capture process in slow collisions between O^{3+} ions and neon dimer targets leads to an unexpected production of low-energy electrons. This production results from the interatomic Coulombic decay process, subsequent to inner-shell single electron capture from one site of the neon dimer. Although pure one-electron capture from the inner shell is expected to be negligible in the low collision energy regime investigated here, the electron production due to this process overtakes by 1 order of magnitude the emission of Auger electrons by the scattered projectiles after double-electron capture. This feature is specific to low charge states of the projectile: similar studies with Xe^{20+} and Ar^{9+} projectiles show no evidence of inner-shell single-electron capture. The dependence of the process on the projectile charge state is interpreted using simple calculations based on the classical over the barrier model.
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Affiliation(s)
- W Iskandar
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - J Matsumoto
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Leredde
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - X Fléchard
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, 14050 Caen Cedex 04, France
| | - B Gervais
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - S Guillous
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - D Hennecart
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - A Méry
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - C L Zhou
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
| | - H Shiromaru
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen cedex 5, France
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5
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Iskandar W, Matsumoto J, Leredde A, Fléchard X, Gervais B, Guillous S, Hennecart D, Méry A, Rangama J, Zhou CL, Shiromaru H, Cassimi A. Atomic site-sensitive processes in low energy ion-dimer collisions. Phys Rev Lett 2014; 113:143201. [PMID: 25325640 DOI: 10.1103/physrevlett.113.143201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Indexed: 06/04/2023]
Abstract
Electron capture processes for low energy Ar(9+) ions colliding with Ar(2) dimer targets are investigated, focusing attention on charge sharing between the two Ar atoms as a function of the molecular orientation and the impact parameter. A preference for charge-asymmetric dissociation channels is observed, with a strong correlation between the projectile scattering angle and the molecular ion orientation. The measurements here provide clear evidence that projectiles distinguish each atom in the target and that electron capture from near-site atoms is favored. Monte Carlo calculations based on the classical over-the-barrier model, with dimer targets represented as two independent atoms, are compared to the data. They give new insight into the dynamics of the collision by providing, for the different electron capture channels, the two-dimensional probability maps p(b), where b is the impact parameter vector in the molecular frame.
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Affiliation(s)
- W Iskandar
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - J Matsumoto
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Leredde
- Physics Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - X Fléchard
- LPC Caen, ENSICAEN, Université de Caen, CNRS/IN2P3, 14050 Caen Cedex 04, France
| | - B Gervais
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - S Guillous
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - D Hennecart
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - A Méry
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - J Rangama
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - C L Zhou
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
| | - H Shiromaru
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minamiosawa, Hachiouji-shi, Tokyo 192-0397, Japan
| | - A Cassimi
- CIMAP, CEA-CNRS-ENSICAEN, BP 5133, F-14070 Caen Cedex 5, France
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6
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Seitz F, Zettergren H, Rousseau P, Wang Y, Chen T, Gatchell M, Alexander JD, Stockett MH, Rangama J, Chesnel JY, Capron M, Poully JC, Domaracka A, Méry A, Maclot S, Vizcaino V, Schmidt HT, Adoui L, Alcamí M, Tielens AGGM, Martín F, Huber BA, Cederquist H. Ions colliding with clusters of fullerenes—Decay pathways and covalent bond formations. J Chem Phys 2013; 139:034309. [DOI: 10.1063/1.4812790] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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7
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Zettergren H, Rousseau P, Wang Y, Seitz F, Chen T, Gatchell M, Alexander JD, Stockett MH, Rangama J, Chesnel JY, Capron M, Poully JC, Domaracka A, Méry A, Maclot S, Schmidt HT, Adoui L, Alcamí M, Tielens AGGM, Martín F, Huber BA, Cederquist H. Formations of dumbbell C118 and C119 inside clusters of C60 molecules by collision with α particles. Phys Rev Lett 2013; 110:185501. [PMID: 23683214 DOI: 10.1103/physrevlett.110.185501] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Indexed: 05/26/2023]
Abstract
We report highly selective covalent bond modifications in collisions between keV alpha particles and van der Waals clusters of C(60) fullerenes. Surprisingly, C(119)(+) and C(118)(+) are the dominant molecular fusion products. We use molecular dynamics simulations to show that C(59)(+) and C(58)(+) ions--effectively produced in prompt knockout processes with He(2+)--react rapidly with C(60) to form dumbbell C(119)(+) and C(118)(+). Ion impact on molecular clusters in general is expected to lead to efficient secondary reactions of interest for astrophysics. These reactions are different from those induced by photons.
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Affiliation(s)
- H Zettergren
- Department of Physics, Stockholm University, S-106 91 Stockholm, Sweden.
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8
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Seitz F, Holm AIS, Zettergren H, Johansson HAB, Rosén S, Schmidt HT, Ławicki A, Rangama J, Rousseau P, Capron M, Maisonny R, Domaracka A, Adoui L, Méry A, Manil B, Huber BA, Cederquist H. Polycyclic aromatic hydrocarbon-isomer fragmentation pathways: Case study for pyrene and fluoranthene molecules and clusters. J Chem Phys 2011; 135:064302. [DOI: 10.1063/1.3622589] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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9
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Matsumoto J, Leredde A, Flechard X, Hayakawa K, Shiromaru H, Rangama J, Zhou CL, Guillous S, Hennecart D, Muranaka T, Mery A, Gervais B, Cassimi A. Asymmetry in multiple-electron capture revealed by radiative charge transfer in Ar dimers. Phys Rev Lett 2010; 105:263202. [PMID: 21231656 DOI: 10.1103/physrevlett.105.263202] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Indexed: 05/30/2023]
Abstract
We measured kinetic energies of the fragment ions of argon dimers multiply ionized by low-energy Ar(9+) collisions. For (Ar2)(4+) dissociation, the asymmetric channel (Ar(3+) + Ar(+)) yield is found unexpectedly higher than the symmetric channel (Ar(2+) + Ar(2+)) yield in contrast with previous observation for covalent molecules or clusters. For the dissociation channel (Ar2)(2+)→Ar(+) + Ar(+), two well-separated peaks were observed, clearly evidencing that the direct Coulombic dissociation and the radiative charge transfer followed by ionic dissociation alternatively occur for the dicationic dimers. The respective intensity of these two peaks provides a direct mean to unravel the respective proportion of one-site and two-site double-electron capture, which are found equal for this collision system.
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Affiliation(s)
- J Matsumoto
- Department of Chemistry, Tokyo Metropolitan University, Tokyo, Japan
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10
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Holm AIS, Zettergren H, Johansson HAB, Seitz F, Rosén S, Schmidt HT, Lawicki A, Rangama J, Rousseau P, Capron M, Maisonny R, Adoui L, Méry A, Manil B, Huber BA, Cederquist H. Ions colliding with cold polycyclic aromatic hydrocarbon clusters. Phys Rev Lett 2010; 105:213401. [PMID: 21231303 DOI: 10.1103/physrevlett.105.213401] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Indexed: 05/26/2023]
Abstract
We report the first experimental study of ions interacting with clusters of polycyclic aromatic hydrocarbon (PAH) molecules. Collisions between 11.25 keV 3He+ or 360 keV 129Xe20+ and weakly bound clusters of one of the smallest PAH molecules, anthracene, show that C14H10 clusters have much higher tendencies to fragment in ion collisions than other weakly bound clusters. The ionization is dominated by peripheral collisions in which the clusters, very surprisingly, are more strongly heated by Xe20+ collisions than by He+ collisions. The appearance size is k=15 for [C ₁₄H₁₀](k)2+.
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Affiliation(s)
- A I S Holm
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
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11
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Sobocinski P, Bari S, Postma J, Alvarado F, Hoekstra R, Manil B, Rangama J, Bernigaud V, Huber BA, Schlathölter T. Isomeric effects in ion-induced fragmentation of α- and β-alanine. ACTA ACUST UNITED AC 2008. [DOI: 10.1088/1742-6596/101/1/012006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Giglio E, Gervais B, Rangama J, Manil B, Huber BA, Duft D, Müller R, Leisner T, Guet C. Shape deformations of surface-charged microdroplets. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 77:036319. [PMID: 18517523 DOI: 10.1103/physreve.77.036319] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2007] [Revised: 12/18/2007] [Indexed: 05/26/2023]
Abstract
We present the deformation pathway of critically charged glycol and water droplets from the onset of the Rayleigh instability and compare it to numerical results, obtained for perfectly conducting inviscid droplets. In this simple model presented here, the time evolution of the droplet shape is given by the velocity potential equation. The Laplace equation for the velocity potential is solved by expanding the potential onto harmonic functions. For the part of the pathway dominated by electrostatic pressure, the calculations reproduce the experimental data nicely, obtained for both, glycol and water microdroplets. We find that the droplet shape and in particular the tips, just before charge emission, are well fitted by a lemon shape. We stress that the tip is tangent to a cone of 39 degrees and thus significantly narrower than a Taylor cone.
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Affiliation(s)
- E Giglio
- Centre Interdisciplinaire de Recherche Ions Lasers (CIRIL), CEA-CNRS-ENSICAEN, Caen, France
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14
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Bari S, Sobocinski P, Postma J, Alvarado F, Hoekstra R, Bernigaud V, Manil B, Rangama J, Huber B, Schlathölter T. Fragmentation of α- and β-alanine molecules by ions at Bragg-peak energies. J Chem Phys 2008; 128:074306. [DOI: 10.1063/1.2830032] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Tomita S, Andersen JU, Cederquist H, Concina B, Echt O, Forster JS, Hansen K, Huber BA, Hvelplund P, Jensen J, Liu B, Manil B, Maunoury L, Brøndsted Nielsen S, Rangama J, Schmidt HT, Zettergren H. Lifetimes of C60(2-) and C70(2-) dianions in a storage ring. J Chem Phys 2007; 124:024310. [PMID: 16422586 DOI: 10.1063/1.2155435] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
C60(2-) and C70(2-) dianions have been produced by electrospray of the monoanions and subsequent electron pickup in a Na vapor cell. The dianions were stored in an electrostatic ring and their decay by electron emission was measured up to 1 s after injection. While C70(2-) ions are stable on this time scale, except for a small fraction of the ions which have been excited by gas collisions, most of the C60(2-) ions decay on a millisecond time scale, with a lifetime depending strongly on their internal temperature. The results can be modeled as decay by electron tunneling through a Coulomb barrier, mainly from thermally populated triplet states about 120 meV above a singlet ground state. At times longer than about 100 ms, the absorption of blackbody radiation plays an important role for the decay of initially cold ions. The tunneling rates obtained from the modeling, combined with WKB estimates of the barrier penetration, give a ground-state energy 200+/-30 meV above the energy of the monoanion plus a free electron and a ground-state lifetime of the order of 20 s.
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Affiliation(s)
- S Tomita
- Department of Physics and Astronomy, University of Aarhus, Aarhus C DK-8000, Denmark
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Concina B, Hvelplund P, Nielsen AB, Nielsen SB, Rangama J, Liu B, Tomita S. Formation and stability of charged amino acid clusters and the role of chirality. J Am Soc Mass Spectrom 2006; 17:275-9. [PMID: 16434210 DOI: 10.1016/j.jasms.2005.10.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 10/25/2005] [Accepted: 10/25/2005] [Indexed: 05/06/2023]
Abstract
Amino acid clusters have been studied by several groups and most notably magic number clusters and chiral recognition have been reported. In this work, we have studied the formation of amino acid clusters by electrospray ionization (ESI) and their stability by high-energy collision-induced dissociation (CID). Appearance sizes were determined for multiply charged clusters where the charge is either due to protons or to sodium ions. Finally, we conclude that chiral selectivity plays an important role in cluster formation but seems to be of minor importance for the fragmentation of mixed clusters.
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Affiliation(s)
- B Concina
- Department of Physics and Astronomy, University of Aarhus, Aarhus, Denmark
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Tomita S, Andersen JU, Bonderup E, Hvelplund P, Liu B, Nielsen SB, Pedersen UV, Rangama J, Hansen K, Echt O. Dynamic Jahn-Teller effects in isolated C60- studied by near-infrared spectroscopy in a storage ring. Phys Rev Lett 2005; 94:053002. [PMID: 15783634 DOI: 10.1103/physrevlett.94.053002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Indexed: 05/24/2023]
Abstract
We have measured the near-infrared absorption spectrum for isolated C60- ions at room temperature. Two bands, at 9145 cm(-1) and 10460 cm(-1), have been identified in addition to the main absorption band at 9382 cm(-1), seen also at low temperature in a matrix. An interpretation based on the theory of dynamic Jahn-Teller effects is proposed.
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Affiliation(s)
- S Tomita
- Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark
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Andersen JU, Cederquist H, Forster JS, Huber BA, Hvelplund P, Jensen J, Liu B, Manil B, Maunoury L, Brøndsted Nielsen S, Pedersen UV, Rangama J, Schmidt HT, Tomita S, Zettergren H. Photodissociation of protonated amino acids and peptides in an ion storage ring. Determination of Arrhenius parameters in the high-temperature limit. Phys Chem Chem Phys 2004. [DOI: 10.1039/b316845j] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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