1
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Stromberg I, Bergmeister S, Ganner L, Zappa F, Scheier P, Echt O, Gruber E. Size limits and fission channels of doubly charged noble gas clusters. Phys Chem Chem Phys 2024; 26:13923-13936. [PMID: 38666766 PMCID: PMC11078200 DOI: 10.1039/d4cp00658e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/25/2024] [Indexed: 05/09/2024]
Abstract
Small, highly charged liquid droplets are unstable with respect to spontaneous charge separation when their size drops below the Rayleigh limit or, in other words, their fissility parameter X exceeds the value 1. The absence of small doubly charged atomic cluster ions in mass spectra below an element-specific appearance size na has sometimes been attributed to the onset of barrierless fission at X = 1. However, more realistic models suggest that na marks the size below which the rate of fission surpasses that of competing dissociative channels, and the Rayleigh limit of doubly charged van der Waals clusters has remained unchartered. Here we explore a novel approach to form small dicationic clusters, namely by Penning ionization of singly charged noble gas (Ng) clusters that are embedded in helium nanodroplets; the dications are then gently extracted from the nanodroplets by low-energy collisions with helium gas. We observe Ngn2+ ions that are about 40% smaller than previously reported for xenon and krypton and about 20% for argon. These findings suggest that fission barriers have been underestimated in previous theoretical work. Furthermore, we measure the size distributions of fragment ions that are produced by collisional excitation of mass-selected dications. At lowest collision gas pressure, dicationic Kr and Xe clusters that are smaller than previously observed are found to evaporate an atom before they undergo highly symmetric fission. The distribution of fragments resulting from fission of small dicationic Ar clusters is bimodal.
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Affiliation(s)
- Ianessa Stromberg
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
- School of Chemistry, University of Edinburgh, Edinburgh, UK
| | - Stefan Bergmeister
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
| | - Lisa Ganner
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
| | - Fabio Zappa
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
| | - Paul Scheier
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
| | - Olof Echt
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
- Department of Physics, University of New Hampshire, Durham, USA
| | - Elisabeth Gruber
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria.
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2
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Bergmeister S, Ganner L, Ončák M, Gruber E. Gas-Phase Electronic Structure of Phthalocyanine Ions: A Study of Symmetry and Solvation Effects. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307816. [PMID: 38225692 DOI: 10.1002/advs.202307816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/19/2023] [Indexed: 01/17/2024]
Abstract
Research into and applications of phthalocyanines (Pc) are mostly connected to their intriguing electronic properties. Here, messenger-type UV-vis spectroscopy of two metal-free ions from the phthalocyanine family, cationic H2Pc+ and H2PcD+, along with their hydrates is performed. They show that the electronic properties of both ions can be traced to those in the conjugate base, Pc2-, however, they are affected by state splitting due to the reduced symmetry; in the H2Pc+ radical cation, a new band appears due to excitations into the singly-occupied molecular orbital. Quantum chemical spectra modeling reproduces all important features of the measured spectra and provides insight into the nature of electronic transitions. Hydration of the ions has only a mild effect on the electronic spectra, showing the stability of the electronic structure with respect to solvation effects.
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Affiliation(s)
- Stefan Bergmeister
- Institute for Ion and Applied Physics, University of Innsbruck, Technikerstraße 25, Innsbruck, 6020, Austria
| | - Lisa Ganner
- Institute for Ion and Applied Physics, University of Innsbruck, Technikerstraße 25, Innsbruck, 6020, Austria
| | - Milan Ončák
- Institute for Ion and Applied Physics, University of Innsbruck, Technikerstraße 25, Innsbruck, 6020, Austria
| | - Elisabeth Gruber
- Institute for Ion and Applied Physics, University of Innsbruck, Technikerstraße 25, Innsbruck, 6020, Austria
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3
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Vilà A, González M. Quantum dynamics of the Br 2 (B-excited state) photodissociation in superfluid helium nanodroplets: importance of the recombination process. Phys Chem Chem Phys 2022; 24:24353-24361. [PMID: 36178095 DOI: 10.1039/d2cp02984g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have studied the Br2 photodissociation dynamics (B ← X electronic transition) of Br2(v = 0, X)@(4He)N doped nanodroplets (T = 0.37 K) at zero angular momentum, with N in the 100-1000 interval. To do this, we have used a quantum mechanical hybrid strategy proposed by us and, as far as we know, this is the second quantum dynamics study available on the photodissociation of molecules in superfluid helium nanodroplets. While the results obtained for some properties are qualitatively similar to those reported previously by us for the Cl2(B ← X) related case (in particular, the oscillating Br final velocity distribution which also arises from quantum interferences), large differences are evident in three key properties: the photodissociation mechanism and probability and the time scale of the process. This can be interpreted on the basis of the significantly lower excitation energy achieved by the Br2(B ← X) transition and the higher reduced mass of Br-Br in comparison to the chlorine case. The Br2(B) photodissociation dynamics is significantly more complex than that of Cl2(B) and leads to the fragmentation of the initial wave packet. Thus, the probability of non-dissociation is equal to 17, 18, 51, 85 and 100% for N = 100, 200, 300, 500 and 1000, respectively, while for chlorine this probability is equal to zero. In spite of the very large experimental difficulties that exist for obtaining nanodroplets with a well defined size, we hope that these results will encourage experimentalists to investigate these interesting systems.
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Affiliation(s)
- Arnau Vilà
- Departament de Ciència dels Materials i Química Física and IQTC, Universitat de Barcelona, Martí i Franquès, 1-11, 08028 Barcelona, Spain.
| | - Miguel González
- Departament de Ciència dels Materials i Química Física and IQTC, Universitat de Barcelona, Martí i Franquès, 1-11, 08028 Barcelona, Spain.
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4
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Niman JW, Kamerin BS, Villers TH, Linker TM, Nakano A, Kresin VV. Probing the presence and absence of metal-fullerene electron transfer reactions in helium nanodroplets by deflection measurements. Phys Chem Chem Phys 2022; 24:10378-10383. [PMID: 35438706 DOI: 10.1039/d2cp00751g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Metal-fullerene compounds are characterized by significant electron transfer to the fullerene cage, giving rise to an electric dipole moment. We use the method of electrostatic beam deflection to verify whether such reactions take place within superfluid helium nanodroplets between an embedded C60 molecule and either alkali (heliophobic) or rare-earth (heliophilic) atoms. The two cases lead to distinctly different outcomes: C60Nan (n = 1-4) display no discernable dipole moment, while C60Yb is strongly polar. This suggests that the fullerene and small alkali clusters fail to form a charge-transfer bond in the helium matrix despite their strong van der Waals attraction. The C60Yb dipole moment, on the other hand, is in agreement with the value expected for an ionic complex.
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Affiliation(s)
- John W Niman
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-0484, USA.
| | - Benjamin S Kamerin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-0484, USA.
| | - Thomas H Villers
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-0484, USA.
| | - Thomas M Linker
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, CA 90089-0242, USA
| | - Aiichiro Nakano
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, CA 90089-0242, USA
| | - Vitaly V Kresin
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089-0484, USA.
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5
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de Lara-Castells MP. First-principles modelling of the new generation of subnanometric metal clusters: Recent case studies. J Colloid Interface Sci 2022; 612:737-759. [PMID: 35033919 DOI: 10.1016/j.jcis.2021.12.186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 10/19/2022]
Abstract
The very recent development of highly selective techniques making possible the synthesis and experimental characterization of subnanometric (subnanometer-sized) metal clusters (even single atoms) is pushing our understanding far beyond the present knowledge in materials science, driving these clusters as a new generation of quantum materials at the lower bounds of nanotechnology. When the size of the metal cluster is reduced to a small number of atoms, the d-band of the metal splits into a subnanometric d-type molecular orbitals network in which all metal atoms are inter-connected, with the inter-connections having the length of a chemical bond (1-2 Å). These molecular characteristics are at the very core of the high stability and novel properties of the smallest metal clusters, with their integration into colloidal materials interacting with the environment having the potential to further boost their performance in applications such as luminescence, sensing, bioimaging, theranostics, energy conversion, catalysis, and photocatalysis. Through the presentation of very recent case studies, this Feature Article is aimed to illustrate how first-principles modelling, including methods beyond the state-of-the-art and an interplay with cutting-edge experiments, is helping to understand the special properties of these clusters at the most fundamental level. Moreover, it will be discussed how superfluid helium droplets can act both as nano-reactors and carriers to achieve the synthesis and surface deposition of metal clusters. This concept will be illustrated with the quantum simulation of the helium droplet-assisted soft-landing of a single Au atom onto a titanium dioxide (TiO2) surface. Next, it will be shown how the application of first-principles methods have disclosed the fundamental reasons why subnanometric Cu5 clusters are resistant to irreversible oxidation, and capable of increasing and extending into the visible region the solar absorption of TiO2, of augmenting its efficiency for photo-catalysis beyond a factor of four, also considering the decomposition and photo-activation of CO2 as a prototypical (photo-) catalytic reaction. Finally, I will discuss how the modification of the same material with subnanometric Ag5 clusters has converted it into a "reporter" of a surface polaron property as well as a novel two-dimensional polaronic material.
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6
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Efficient Formation of Size-Selected Clusters upon Pickup of Dopants into Multiply Charged Helium Droplets. Int J Mol Sci 2022; 23:ijms23073613. [PMID: 35408968 PMCID: PMC8998201 DOI: 10.3390/ijms23073613] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/18/2022] [Accepted: 03/24/2022] [Indexed: 02/01/2023] Open
Abstract
Properties of clusters often depend critically on the exact number of atomic or molecular building blocks, however, most methods of cluster formation lead to a broad, size distribution and cluster intensity anomalies that are often designated as magic numbers. Here we present a novel approach of breeding size-selected clusters via pickup of dopants into multiply charged helium nanodroplets. The size and charge state of the initially undoped droplets and the vapor pressure of the dopant in the pickup region, determines the size of the dopant cluster ions that are extracted from the host droplets, via evaporation of the helium matrix in a collision cell filled with room temperature helium or via surface collisions. Size distributions of the selected dopant cluster ions are determined utilizing a high-resolution time of flight mass spectrometer. The comparison of the experimental data, with simulations taking into consideration the pickup probability into a shrinking He droplet due to evaporation during the pickup process, provides a simple explanation for the emergence of size distributions that are narrower than Poisson.
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7
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Schouder CA, Chatterley AS, Pickering JD, Stapelfeldt H. Laser-Induced Coulomb Explosion Imaging of Aligned Molecules and Molecular Dimers. Annu Rev Phys Chem 2022; 73:323-347. [PMID: 35081323 DOI: 10.1146/annurev-physchem-090419-053627] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We discuss how Coulomb explosion imaging (CEI), triggered by intense femtosecond laser pulses and combined with laser-induced alignment and covariance analysis of the angular distributions of the recoiling fragment ions, provides new opportunities for imaging the structures of molecules and molecular complexes. First, focusing on gas phase molecules, we show how the periodic torsional motion of halogenated biphenyl molecules can be measured in real time by timed CEI, and how CEI of one-dimensionally aligned difluoroiodobenzene molecules can uniquely identify four structural isomers. Next, focusing on molecular complexes formed inside He nanodroplets, we show that the conformations of noncovalently bound dimers or trimers, aligned in one or three dimensions, can be determined by CEI. Results presented for homodimers of CS2, OCS, and bromobenzene pave the way for femtosecond time-resolved structure imaging of molecules undergoing bimolecular interactions and ultimately chemical reactions. Expected final online publication date for the Annual Review of Physical Chemistry, Volume 73 is April 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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8
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Alić J, Messner R, Lackner F, Ernst WE, Šekutor M. London dispersion dominating diamantane packing in helium nanodroplets. Phys Chem Chem Phys 2021; 23:21833-21839. [PMID: 34554159 PMCID: PMC8494270 DOI: 10.1039/d1cp03380h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/16/2021] [Indexed: 11/21/2022]
Abstract
Diamantane clusters formed inside superfluid helium nanodroplets were analyzed by time-of-flight mass spectrometry. Distinct cluster sizes were identified as "magic numbers" and the corresponding feasible structures for clusters consisting of up to 19 diamantane molecules were derived from meta-dynamics simulations and subsequent DFT computations. The obtained interaction energies were attributed to London dispersion attraction. Our findings demonstrate that diamantane units readily form assemblies even at low pressures and near-zero Kelvin temperatures, confirming the importance of the intermolecular dispersion effect for condensation of matter.
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Affiliation(s)
- Jasna Alić
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia.
| | - Roman Messner
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
| | - Florian Lackner
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
| | - Wolfgang E Ernst
- Institute of Experimental Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria.
| | - Marina Šekutor
- Department of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička cesta 54, 10 000 Zagreb, Croatia.
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9
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A Path Integral Molecular Dynamics Simulation of a Harpoon-Type Redox Reaction in a Helium Nanodroplet. Molecules 2021; 26:molecules26195783. [PMID: 34641327 PMCID: PMC8510490 DOI: 10.3390/molecules26195783] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/14/2021] [Accepted: 09/21/2021] [Indexed: 11/17/2022] Open
Abstract
We present path integral molecular dynamics (PIMD) calculations of an electron transfer from a heliophobic Cs2 dimer in its (3Σu) state, located on the surface of a He droplet, to a heliophilic, fully immersed C60 molecule. Supported by electron ionization mass spectroscopy measurements (Renzler et al., J. Chem. Phys.2016, 145, 181101), this spatially quenched reaction was characterized as a harpoon-type or long-range electron transfer in a previous high-level ab initio study (de Lara-Castells et al., J. Phys. Chem. Lett.2017, 8, 4284). To go beyond the static approach, classical and quantum PIMD simulations are performed at 2 K, slightly below the critical temperature for helium superfluidity (2.172 K). Calculations are executed in the NVT ensemble as well as the NVE ensemble to provide insights into real-time dynamics. A droplet size of 2090 atoms is assumed to study the impact of spatial hindrance on reactivity. By changing the number of beads in the PIMD simulations, the impact of quantization can be studied in greater detail and without an implicit assumption of superfluidity. We find that the reaction probability increases with higher levels of quantization. Our findings confirm earlier, static predictions of a rotational motion of the Cs2 dimer upon reacting with the fullerene, involving a substantial displacement of helium. However, it also raises the new question of whether the interacting species are driven out-of-equilibrium after impurity uptake, since reactivity is strongly quenched if a full thermal equilibration is assumed. More generally, our work points towards a novel mechanism for long-range electron transfer through an interplay between nuclear quantum delocalization within the confining medium and delocalized electronic dispersion forces acting on the two reactants.
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10
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González-Lezana T, Echt O, Gatchell M, Bartolomei M, Campos-Martínez J, Scheier P. Solvation of ions in helium. INT REV PHYS CHEM 2020. [DOI: 10.1080/0144235x.2020.1794585] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Tomás González-Lezana
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas IFF-CSIC, Madrid, Spain
| | - Olof Echt
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
- Department of Physics, University of New Hampshire, Durham, NH, USA
| | - Michael Gatchell
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - Massimiliano Bartolomei
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas IFF-CSIC, Madrid, Spain
| | - José Campos-Martínez
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas IFF-CSIC, Madrid, Spain
| | - Paul Scheier
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
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11
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Thaler B, Meyer M, Heim P, Koch M. Long-Lived Nuclear Coherences inside Helium Nanodroplets. PHYSICAL REVIEW LETTERS 2020; 124:115301. [PMID: 32242724 DOI: 10.1103/physrevlett.124.115301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 02/06/2020] [Indexed: 05/20/2023]
Abstract
Much of our knowledge about dynamics and functionality of molecular systems has been achieved with femtosecond time-resolved spectroscopy. Despite extensive technical developments over the past decades, some classes of systems have eluded dynamical studies so far. Here, we demonstrate that superfluid helium nanodroplets, acting as a thermal bath of 0.4 K temperature to stabilize weakly bound or reactive systems, are well suited for time-resolved studies of single molecules solvated in the droplet interior. By observing vibrational wave packet motion of indium dimers (In_{2}) for tens of picoseconds, we demonstrate that the perturbation imposed by this quantum liquid can be lower by a factor of 10-100 compared to any other solvent, which uniquely allows us to study processes depending on long nuclear coherence in a dissipative environment. Furthermore, tailor-made microsolvation environments inside droplets will enable us to investigate the solvent influence on intramolecular dynamics in a wide tuning range from molecular isolation to strong molecule-solvent coupling.
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Affiliation(s)
- Bernhard Thaler
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
| | - Miriam Meyer
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
| | - Pascal Heim
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
| | - Markus Koch
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria
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12
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Kranabetter L, Bersenkowitsch NK, Martini P, Gatchell M, Kuhn M, Laimer F, Schiller A, Beyer MK, Ončák M, Scheier P. Considerable matrix shift in the electronic transitions of helium-solvated cesium dimer cation Cs 2He. Phys Chem Chem Phys 2019; 21:25362-25368. [PMID: 31702748 PMCID: PMC7116336 DOI: 10.1039/c9cp04790e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
We investigate the photodissociation of helium-solvated cesium dimer cations using action spectroscopy and quantum chemical calculations. The spectrum of Cs2He+ shows three distinct absorption bands into both bound and dissociative states. Upon solvation with further helium atoms, considerable shifts of the absorption bands are observed, exceeding 0.1 eV (850 cm-1) already for Cs2He10+, along with significant broadening. The shifts are highly sensitive to the character of the excited state. Our calculations show that helium atoms adsorb on the ends of Cs2+. The shifts are particularly pronounced if the excited state orbitals extend to the area occupied by the helium atoms. In this case, Pauli repulsion leads to a deformation of the excited state orbitals, resulting in the observed blue shift of the transition. Since the position of the weakly bound helium atoms is ill defined, Pauli repulsion also explains the broadening.
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Affiliation(s)
- Lorenz Kranabetter
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Nina K Bersenkowitsch
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Paul Martini
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Michael Gatchell
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria. and Department of Physics, Stockholm University, 106 91 Stockholm, Sweden
| | - Martin Kuhn
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Felix Laimer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Arne Schiller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
| | - Milan Ončák
- 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.
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13
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Zanchet A, López-Caballero P, Mitrushchenkov AO, Buceta D, López-Quintela MA, Hauser AW, Pilar de Lara-Castells M. On the Stability of Cu 5 Catalysts in Air Using Multireference Perturbation Theory. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:27064-27072. [PMID: 33101568 PMCID: PMC7575162 DOI: 10.1021/acs.jpcc.9b08378] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/15/2019] [Indexed: 05/21/2023]
Abstract
An ab initio study of the interaction of O2, the most abundant radical and oxidant species in the atmosphere, with a Cu5 cluster, a new generation atomic metal catalyst, is presented. The open-shell nature of the reactant species is properly accounted for by using the multireference perturbation theory, allowing the experimentally confirmed resistivity of Cu5 clusters toward oxidation to be investigated. Approximate reaction pathways for the transition from physisorption to chemisorption are calculated for the interaction of O2 with quasi-iso-energetic trapezoidal planar and trigonal bipyramidal structures. Within the multireference approach, the transition barrier for O2 activation can be interpreted as an avoided crossing between adiabatic states (neutral and ionic), which provides new insights into the charge-transfer process and gives better estimates for this hard to localize and therefore often neglected first intermediate state. For Cu5 arranged in a bipyramidal structure, the O-O bond cleavage is confirmed as the rate-determining step. However, for planar Cu5, the high energy barrier for O2 activation, related to a very pronounced avoided crossing when going from physisorption to chemisorption, determines the reactivity in this case.
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Affiliation(s)
- Alexandre Zanchet
- Instituto
de Física Fundamental (AbinitSim Unit), CSIC, Serrano 123, 28006 Madrid, Spain
- Departamento
de Química Física, Facultad de Ciencias Químicas, Universidad de Salamanca, 37008 Salamanca, Spain
| | | | - Alexander O. Mitrushchenkov
- Laboratoire
Modélisationet Simulation Multi Echelle, Université Paris-Est, MSME UMR 8208, CNRS, UPEC, UPEM, 5 Bd Descartes, Champs-sur-Marne, F-77454 Marne la Vallée, France
| | - David Buceta
- Laboratory
of Nanotechnology and Magnetism, University
of Santiago de Compostela, E-15782 Santiago de Compostela, Spain
| | - Manuel Arturo López-Quintela
- Laboratory
of Nanotechnology and Magnetism, University
of Santiago de Compostela, E-15782 Santiago de Compostela, Spain
| | - Andreas W. Hauser
- Graz
University of Technology, Institute of Experimental
Physics, Petersgasse
16, 8010 Graz, Austria
- E-mail: (A.W.H.)
| | - María Pilar de Lara-Castells
- Instituto
de Física Fundamental (AbinitSim Unit), CSIC, Serrano 123, 28006 Madrid, Spain
- E-mail: . Phone: +34 915616800
(941026) (M.P.d.L.-C.)
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14
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Blancafort-Jorquera M, Vilà A, González M. Quantum-classical dynamics of the capture of neon atoms by superfluid helium nanodroplets. Phys Chem Chem Phys 2018; 20:29737-29753. [DOI: 10.1039/c8cp05140b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The capture dynamics of Ne by a HeND was studied theoretically in a detailed manner (energy and angular momentum transfer and vortex formation).
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Affiliation(s)
| | - Arnau Vilà
- Departament de Ciència de Materials i Química Física and IQTC
- Universitat de Barcelona
- Barcelona
- Spain
| | - Miguel González
- Departament de Ciència de Materials i Química Física and IQTC
- Universitat de Barcelona
- Barcelona
- Spain
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15
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de Lara-Castells MP, Hauser AW, Mitrushchenkov AO. Ab Initio Confirmation of a Harpoon-Type Electron Transfer in a Helium Droplet. J Phys Chem Lett 2017; 8:4284-4288. [PMID: 28841325 DOI: 10.1021/acs.jpclett.7b01910] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
An ab initio study of a long-range electron transfer or "harpoon"-type process from Cs and Cs2 to C60 in a superfluid helium droplet is presented. The heliophobic Cs or Cs2 species are initially located at the droplet surface, while the heliophilic C60 molecule is fully immersed in the droplet. First, probabilities for the electron transfer in the gas phase are calculated for reactants with velocities below the critical Landau velocity of 57 m/s to account for the superfluid helium environment. Next, reaction pathways are derived that also include the repulsive contribution from the extrusion of helium upon the approach of the two reactants. Our results are in perfect agreement with recent experimental measurements of electron ionization mass spectroscopy [ Renzler , M. ; et al., J. Chem. Phys. 2016 , 145 , 181101 ], showing a high possibility for the formation of a Cs2-C60 complex inside of the droplet through a direct harpoon-type electron transfer involving the rotation of the molecule but a negligibly low reactivity for atomic Cs.
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Affiliation(s)
| | - Andreas W Hauser
- Institute of Experimental Physics, Graz University of Technology , Petersgasse 16, 8010 Graz, Austria
| | - Alexander O Mitrushchenkov
- Laboratoire Modélisation et Simulation Multi Echelle, Université Paris-Est , MSME UMR 8208 CNRS 5 bd Descartes, 77454 Marne-la-Vallée, France
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16
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Ancilotto F, Barranco M, Coppens F, Eloranta J, Halberstadt N, Hernando A, Mateo D, Pi M. Density functional theory of doped superfluid liquid helium and nanodroplets. INT REV PHYS CHEM 2017. [DOI: 10.1080/0144235x.2017.1351672] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Francesco Ancilotto
- Dipartimento di Fisica e Astronomia ‘Galileo Galilei’ and CNISM, Università di Padova, Padova, Italy
- CNR-IOM Democritos, Trieste, Italy
| | - Manuel Barranco
- Facultat de Física, Departament FQA, Universitat de Barcelona, Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
- Laboratoire des Collisions, Agrégats et Réactivité, IRSAMC, Université Toulouse 3 and CNRS, Toulouse Cedex 09, France
| | - François Coppens
- Laboratoire des Collisions, Agrégats et Réactivité, IRSAMC, Université Toulouse 3 and CNRS, Toulouse Cedex 09, France
| | - Jussi Eloranta
- Department of Chemistry and Biochemistry, California State University at Northridge, Northridge, CA, USA
| | - Nadine Halberstadt
- Laboratoire des Collisions, Agrégats et Réactivité, IRSAMC, Université Toulouse 3 and CNRS, Toulouse Cedex 09, France
| | - Alberto Hernando
- Social Thermodynamics Applied Research (SThAR), EPFL Innovation Park, Lausanne, Switzerland
| | - David Mateo
- Applied Complexity Group, Singapore University of Technology and Design, Singapore, Singapore
| | - Martí Pi
- Facultat de Física, Departament FQA, Universitat de Barcelona, Barcelona, Spain
- Institute of Nanoscience and Nanotechnology (IN2UB), Universitat de Barcelona, Barcelona, Spain
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17
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Renzler M, Kranabetter L, Goulart M, Scheier P, Echt O. Positively and Negatively Charged Cesium and (C 60) m Cs n Cluster Ions. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2017; 121:10817-10823. [PMID: 28572870 PMCID: PMC5447244 DOI: 10.1021/acs.jpcc.6b11928] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Revised: 12/22/2016] [Indexed: 05/29/2023]
Abstract
We report on the formation and ionization of cesium and C60Cs clusters in superfluid helium nanodroplets. Size distributions of positively and negatively charged (C60) m Cs n± ions have been measured for m ≤ 7, n ≤ 12. Reproducible intensity anomalies are observed in high-resolution mass spectra. For both charge states, (C60) m Cs3± and (C60) m Cs5± are particularly abundant, with little dependence on the value of m. Distributions of bare cesium cluster ions also indicate enhanced stability of Cs3± and Cs5±, in agreement with theoretical predictions. These findings contrast with earlier reports on highly Cs-doped cationic fullerene aggregates which showed enhanced stability of C60Cs6 building blocks attributed to charge transfer. The dependence of the (C60) m Cs3- anion yield on electron energy shows a resonance that, surprisingly, oscillates in strength as m increases from 1 to 6.
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Affiliation(s)
- Michael Renzler
- Institut
für Ionenphysik und Angewandte Physik, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
| | - Lorenz Kranabetter
- Institut
für Ionenphysik und Angewandte Physik, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
| | - Marcelo Goulart
- Institut
für Ionenphysik und Angewandte Physik, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
| | - Paul Scheier
- Institut
für Ionenphysik und Angewandte Physik, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
| | - Olof Echt
- Institut
für Ionenphysik und Angewandte Physik, University of Innsbruck, Technikerstrasse 25, A-6020 Innsbruck, Austria
- Department
of Physics, University of New Hampshire, Durham, New Hampshire 03824, United States
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18
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Hauser AW, de Lara-Castells MP. Spatial quenching of a molecular charge-transfer process in a quantum fluid: the Cs x-C 60 reaction in superfluid helium nanodroplets. Phys Chem Chem Phys 2017; 19:1342-1351. [PMID: 27975088 DOI: 10.1039/c6cp06858h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A recent experimental study [Renzler et al., J. Chem. Phys., 2016, 145, 181101] on superfluid helium nanodroplets reported different reactivities for Cs atoms and Cs2 dimers with C60 fullerenes inside helium droplets. Alkali metal atoms and clusters are heliophobic, therefore typically residing on the droplet surface, while fullerenes are fully immersed into the droplet. In this theoretical study, which combines standard methods of computational chemistry with orbital-free helium density functional theory, we show that the experimental findings can be interpreted in the light of a quenched electron-transfer reaction between the fullerene and the alkali dopant, which is additionally hindered by a reaction barrier stemming from the necessary extrusion of helium upon approach of the two reactants.
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Affiliation(s)
- Andreas W Hauser
- Graz University of Technology, Institute of Experimental Physics, Petersgasse 16, 8010 Graz, Austria.
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19
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Goulart M, Zappa F, Ellis AM, Bartl P, Ralser S, Scheier P. Electron ionization of helium droplets containing C60 and alcohol clusters. Phys Chem Chem Phys 2017; 19:24197-24201. [DOI: 10.1039/c7cp02994b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alcoholic chemical reactions at similar conditions as the interstellar medium can be heavily hampered by the presence of C60.
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Affiliation(s)
- M. Goulart
- Institut für Ionenphysik und Angewandte Physik
- Innsbruck
- Austria
- Departamento de Física
- UFJF
| | - F. Zappa
- Departamento de Física
- UFJF
- Juiz de Fora
- Brazil
| | - A. M. Ellis
- Department of Chemistry
- University of Leicester
- UK
| | - P. Bartl
- Institut für Ionenphysik und Angewandte Physik
- Innsbruck
- Austria
| | - S. Ralser
- Institut für Ionenphysik und Angewandte Physik
- Innsbruck
- Austria
| | - P. Scheier
- Institut für Ionenphysik und Angewandte Physik
- Innsbruck
- Austria
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20
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Krotscheck E, Zillich RE. Solvation of Mg in helium-4: Are there meta-stable Mg dimers? J Chem Phys 2016; 145:244317. [DOI: 10.1063/1.4972811] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Eckhard Krotscheck
- Department of Physics, University at Buffalo SUNY, Buffalo, New York 14260, USA
- Institute for Theoretical Physics, Johannes Kepler Universität Linz, Altenbergerstraße 69, A-4040 Linz, Austria
| | - Robert E. Zillich
- Institute for Theoretical Physics, Johannes Kepler Universität Linz, Altenbergerstraße 69, A-4040 Linz, Austria
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