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Borocci S, Giordani M, Grandinetti F. Bonding Motifs of Noble-Gas Compounds As Described by the Local Electron Energy Density. J Phys Chem A 2015; 119:6528-41. [PMID: 25988571 DOI: 10.1021/acs.jpca.5b03043] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The bonding situation of some exemplary noble-gas (Ng) compounds, including HNg(+), HNgF, FNgO(-), Ng-HF, and NgBeO (Ng = He-Xe) was assayed by examining their local electron energy density H(r). In general, this function partitions the space of atomic species (neutral and ionic) into inner regions of negative values and outer regions of positive values. In the formation of chemical bonds, these atomic regions combine so to form a molecular H(r), Hmol(r), whose plotted form naturally shows the "covalent" and "noncovalent" regions of the molecular species and allows also the recognition of different types of noncovalent interactions such van der Waals, hydrogen, and ionic or partially ionic bonds. The qualitative assignment of the various bonding motifs is corroborated by the topological analysis of Hmol(r), which typically includes several critical points of rank 3 and variable signature. These points are, in particular, characterized here in terms of their bond degree (BD). From a previous definition (Espinosa J. Chem. Phys. 2002, 117, 5529-5542), this quantity is taken as the ratio between the energy density calculated at the critical point of H(r), H(rc), and the corresponding electron density ρ(rc): BD = -H(rc)/ρ(rc). Thus, the BD is positive for covalent interactions (H(rc) < 0) and negative for noncovalent interactions (H(rc) > 0). For structurally related species, the BD result, in general, positively correlated with the binding energies and is, therefore, a semiquantitative index of stability. The present study suggests the general validity of the Hmol(r) to effectively assay the bonding motifs of noble-gas compounds.
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Affiliation(s)
- Stefano Borocci
- Dipartimento per la Innovazione nei sistemi Biologici, Agroalimentari e Forestali (DIBAF), Università della Tuscia, L.go dell'Università, s.n.c., 01100 Viterbo, Italy.,Istituto per le Metodologie Chimiche del CNR, Via Salaria, Km 29.500, 00015 Monterotondo, RM, Italy
| | - Maria Giordani
- Dipartimento per la Innovazione nei sistemi Biologici, Agroalimentari e Forestali (DIBAF), Università della Tuscia, L.go dell'Università, s.n.c., 01100 Viterbo, Italy.,Istituto per le Metodologie Chimiche del CNR, Via Salaria, Km 29.500, 00015 Monterotondo, RM, Italy
| | - Felice Grandinetti
- Dipartimento per la Innovazione nei sistemi Biologici, Agroalimentari e Forestali (DIBAF), Università della Tuscia, L.go dell'Università, s.n.c., 01100 Viterbo, Italy.,Istituto per le Metodologie Chimiche del CNR, Via Salaria, Km 29.500, 00015 Monterotondo, RM, Italy
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Zero-field mobilities in helium: highly accurate values for use in ion mobility spectrometry. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s12127-011-0079-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Withers CD, Wright TG, Viehland LA, Grossman L, Kirkpatrick CC, Lee EPF. Theoretical study of Cl−RG (rare gas) complexes and transport of Cl− through RG (RG = He–Rn). J Chem Phys 2011; 135:024312. [DOI: 10.1063/1.3598472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Grandinetti F. Review: gas-phase ion chemistry of the noble gases: recent advances and future perspectives. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2011; 17:423-463. [PMID: 22173538 DOI: 10.1255/ejms.1151] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
This review article surveys recent experimental and theoretical advances in the gas-phase ion chemistry of the noble gases. Covered issues include the interaction of the noble gases with metal and non-metal cations, the conceivable existence of covalent noble-gas anions, the occurrence of ion-molecule reactions involving singly-charged xenon cations, and the occurrence of bond-forming reactions involving doubly-charged cations. Research themes are also highlighted, that are expected to attract further interest in the future.
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Affiliation(s)
- Felice Grandinetti
- Dipartimento per la Innovazione nei sistemi Biologici, Agroalimentari e Forestali, Università della Tuscia, L.go dell'Università, s.n.c., 01100 Viterbo, Italy.
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Wright TG, Breckenridge WH. Radii of atomic ions determined from diatomic ion-He bond lengths. J Phys Chem A 2010; 114:3182-9. [PMID: 20055395 DOI: 10.1021/jp9091927] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We propose a new definition of the effective radius of an atomic ion: the bond distance (R(e)) of the ion/He diatomic complex minus the van der Waals radius of the helium atom. Our rationale is that He is the most chemically inert and least polarizable atom, so that its interaction with the outer portions of the electron cloud causes the smallest perturbation of it. We show that such radii, which we denote R(XHe), make good qualitative sense. We also compare our R(XHe) values to more traditional ionic radii from solid crystal X-ray measurements, as well as estimates of such radii from "ionic" gas-phase MF, MOM, MF(+), and MO molecules, where M is a metal atom. Such comparisons lead to interesting conclusions about bonding in ionic crystals and in simple gas-phase oxide and fluoride molecules. The definition is shown to be reasonable for -1, +1, and even for many of the larger +2 atomic ions. Another advantage of the R(XHe) definition is that it is also consistently valid for ground states and excited states of both neutral atoms and atomic ions, even for open-shell np and nd cases where the electron clouds of the ions are not spherically symmetric and R(XHe) thus depends on the "approach" direction of the He atom. Finally, we note that when there is a contribution from covalent bonding with the He atom, and/or in cases where the ion is small and has a very high charge, so that there is distortion even of the He 1s electrons, R(XHe) is not expected to be representative of the size of the ion. We then suggest that in these cases small, and sometimes unphysical, values of R(XHe) are diagnostic of the fact that simple "physical" interactions have been supplemented by a "chemical" component.
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Affiliation(s)
- Timothy G Wright
- School of Chemistry, University of Nottingham, University Park, United Kingdom NG7 2RD.
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Buchachenko AA, Wright TG, Lee EPF, Viehland LA. Interaction Potentials, Spectroscopy, and Transport Properties of the Br+−RG Systems (RG = He−Ar). J Phys Chem A 2009; 113:14431-8. [DOI: 10.1021/jp903811b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexei A. Buchachenko
- Laboratory of Molecular Structure and Quantum Mechanics, Department of Chemistry, Moscow State Universty, Moscow 119991, Russia, School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom, School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom, and Department of Science, Chatham University, Pittsburgh, Pennsylvania 15232
| | - Timothy G. Wright
- Laboratory of Molecular Structure and Quantum Mechanics, Department of Chemistry, Moscow State Universty, Moscow 119991, Russia, School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom, School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom, and Department of Science, Chatham University, Pittsburgh, Pennsylvania 15232
| | - Edmond P. F. Lee
- Laboratory of Molecular Structure and Quantum Mechanics, Department of Chemistry, Moscow State Universty, Moscow 119991, Russia, School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom, School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom, and Department of Science, Chatham University, Pittsburgh, Pennsylvania 15232
| | - Larry A. Viehland
- Laboratory of Molecular Structure and Quantum Mechanics, Department of Chemistry, Moscow State Universty, Moscow 119991, Russia, School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom, School of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom, and Department of Science, Chatham University, Pittsburgh, Pennsylvania 15232
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Coccia E, Marinetti F, Bodo E, Gianturco FA. Chemical solutions in a quantum solvent: anionic electrolytes in 4He nanodroplets. Chemphyschem 2008; 9:1323-30. [PMID: 18461589 DOI: 10.1002/cphc.200800132] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Variational and diffusion Monte Carlo (VMC and DMC) calculations are presented for anionic electrolytes solvated in (4)He. The electrolytes have the general structure X(-)(He)(N), with X=F, Cl, Br and I, and N varying up to 40 (41 for I(-)). The overall interaction potential is obtained from accurate ab initio data for the two-body components and then using the sum-of-potentials approximation. Our computational scheme is a robust procedure, giving us accurate trial wavefunctions that can be used to perform high-quality DMC calculations. The results indicate very marked delocalization and permanence of the liquid-like quantum features of the solvent adatoms surrounding the anionic impurities. This finding stands in contrast to the more structured, solid-like behavior of the quantum solutions with alkali metal cations embedded in He nanodroplets. While other negatively charged species such as H(-) have shown an overall repulsive interaction with He, the present calculations clearly indicate that the halogen anions remain solvated within liquid-like solvent "bubbles" of species-dependent size.
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Affiliation(s)
- Emanuele Coccia
- Department of Chemistry and CNISM, University of Rome La Sapienza, Piazzale A. Moro, 00185 Rome, Italy.
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Schüller A, Winter H. Supernumerary rainbows in the angular distribution of scattered projectiles for grazing collisions of fast atoms with a LiF(001) surface. PHYSICAL REVIEW LETTERS 2008; 100:097602. [PMID: 18352749 DOI: 10.1103/physrevlett.100.097602] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Indexed: 05/26/2023]
Abstract
Fast atoms with keV energies are scattered under a grazing angle of incidence from a clean and flat LiF(001) surface. For scattering along low index azimuthal directions within the surface plane ("axial surface channeling") we observe pronounced peak structures in the angular distributions for scattered projectiles that are attributed to "supernumerary rainbows." This phenomenon can be understood in the framework of quantum scattering only and is observed here up to projectile energies of 20 keV. We demonstrate that the interaction potential and, in particular, its corrugation for fast atomic projectiles at surfaces can be derived with a high accuracy.
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Affiliation(s)
- A Schüller
- Institut für Physik, Humboldt Universität zu Berlin, Brook-Taylor-Strasse 6, D-12489 Berlin-Adlershof, Germany
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Accurate potential energy curves for Zn+–Rg (Rg=He–Rn): Spectroscopy and transport coefficients. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.10.104] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Antoniotti P, Borocci S, Bronzolino N, Cecchi P, Grandinetti F. Noble gas anions: a theoretical investigation of FNgBN- (Ng = He-Xe). J Phys Chem A 2007; 111:10144-51. [PMID: 17854163 DOI: 10.1021/jp0743673] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Noble gas anions of general formula FNgBN- (Ng = He-Xe) have been investigated by MP2, coupled-cluster, and multireference-CI calculations with correlation-consistent basis sets. These species reside in deep wells on the singlet potential energy surface and are thermodynamically stable with respect to the loss of F, F-, BN, and BN-. They are unstable with respect to Ng + FBN-, but at least for Ng = Ar, Kr, and Xe, the involved energy barriers are high enough to suggest their conceivable existence as metastable species. The stability of FNgBN- arises from the strong F--stabilization of the elusive NgBN. The character of the boron-noble gas bond passes from purely ionic for FHeBN- and FNeBN- to covalent for FXeBN-.
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Affiliation(s)
- Paola Antoniotti
- Dipartimento di Chimica Generale ed Organica Applicata, Università degli Studi di Torino, C.so M. D'Azeglio, 48, 10125 Torino, Italy
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Gray BR, Lee EPF, Yousef A, Shrestha S, Viehland LA, Wright TG. Accurate potential energy curves for Tl+–Rg (Rg=He–Rn): spectroscopy and transport coefficients. Mol Phys 2006. [DOI: 10.1080/00268970601075246] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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