1
|
Heller J, Cunningham EM, Hartmann JC, van der Linde C, Ončák M, Beyer MK. Size-dependent H and H 2 formation by infrared multiple photon dissociation spectroscopy of hydrated vanadium cations, V +(H 2O) n, n = 3-51. Phys Chem Chem Phys 2022; 24:14699-14708. [PMID: 35438100 PMCID: PMC9215701 DOI: 10.1039/d2cp00833e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infrared spectra of the hydrated vanadium cation (V+(H2O)n; n = 3–51) were measured in the O–H stretching region employing infrared multiple photon dissociation (IRMPD) spectroscopy. Spectral fingerprints, along with size-dependent fragmentation channels, were observed and rationalized by comparing to spectra simulated using density functional theory. Photodissociation leading to water loss was found for cluster sizes n = 3–7, consistent with isomers featuring intact water ligands. Loss of molecular hydrogen was observed as a weak channel starting at n = 8, indicating the advent of inserted isomers, HVOH+(H2O)n−1. The majority of ions for n = 8, however, are composed of two-dimensional intact isomers, concordant with previous infrared studies on hydrated vanadium. A third channel, loss of atomic hydrogen, is observed weakly for n = 9–11, coinciding with the point at which the H and H2O calculated binding energies become energetically competitive for intact isomers. A clear and sudden spectral pattern and fragmentation channel intensity at n = 12 suggest a structural change to inserted isomers. The H2 channel intensity decreases sharply and is not observed for n = 20 and 25–51. IRMPD spectra for clusters sizes n = 15–51 are qualitatively similar indicating no significant structural changes, and are thought to be composed of inserted isomers, consistent with recent electronic spectroscopy experiments. Infrared multiple photon dissociation spectra of V+(H2O)n depend on experiment conditions, with strong kinetic shift effects for large clusters.![]()
Collapse
Affiliation(s)
- Jakob Heller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Ethan M Cunningham
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Jessica C Hartmann
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| |
Collapse
|
2
|
Heller J, Pascher TF, van der Linde C, Ončák M, Beyer MK. Photochemical Hydrogen Evolution at Metal Centers Probed with Hydrated Aluminium Cations, Al + (H 2 O) n , n=1-10. Chemistry 2021; 27:16367-16376. [PMID: 34636449 PMCID: PMC9298212 DOI: 10.1002/chem.202103289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Indexed: 11/24/2022]
Abstract
Hydrated aluminium cations have been investigated as a photochemical model system with up to ten water molecules by UV action spectroscopy in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. Intense photodissociation was observed starting at 4.5 eV for two to eight water molecules with loss of atomic hydrogen, molecular hydrogen and water molecules. Quantum chemical calculations for n=2 reveal that solvation shifts the intense 3s-3p excitations of Al+ into the investigated photon energy range below 5.5 eV. During the photochemical relaxation, internal conversion from S1 to T2 takes place, and photochemical hydrogen formation starts on the T2 surface, which passes through a conical intersection, changing to T1 . On this triplet surface, the electron that was excited to the Al 3p orbital is transferred to a coordinated water molecule, which dissociates into a hydroxide ion and a hydrogen atom. If the system remains in the triplet state, this hydrogen radical is lost directly. If the system returns to singlet multiplicity, the reaction may be reversed, with recombination with the hydroxide moiety and electron transfer back to aluminium, resulting in water evaporation. Alternatively, the hydrogen radical can attack the intact water molecule, forming molecular hydrogen and aluminium dihydroxide. Photodissociation is observed for up to n=8. Clusters with n=9 or 10 occur exclusively as HAlOH+ (H2 O)n-1 and are transparent in the investigated energy range. For n=4-8, a mixture of Al+ (H2 O)n and HAlOH+ (H2 O)n-1 is present in the experiment.
Collapse
Affiliation(s)
- Jakob Heller
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Tobias F. Pascher
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| |
Collapse
|
3
|
Heller J, Pascher TF, Muß D, van der Linde C, Beyer MK, Ončák M. Photochemistry and UV/vis spectroscopy of hydrated vanadium cations, V +(H 2O) n, n = 1-41, a model system for photochemical hydrogen evolution. Phys Chem Chem Phys 2021; 23:22251-22262. [PMID: 34396372 PMCID: PMC8514045 DOI: 10.1039/d1cp02382a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/06/2021] [Indexed: 12/18/2022]
Abstract
Photochemical hydrogen evolution provides fascinating perspectives for light harvesting. Hydrated metal ions in the gas phase are ideal model systems to study elementary steps of this reaction on a molecular level. Here we investigate mass-selected hydrated monovalent vanadium ions, with a hydration shell ranging from 1 to 41 water molecules, by photodissociation spectroscopy. The most intense absorption bands correspond to 3d-4p transitions, which shift to the red from n = 1 to n = 4, corresponding to the evolution of a square-planar complex. Additional water molecules no longer interact directly with the metal center, and no strong systematic shift is observed in larger clusters. Evolution of atomic and molecular hydrogen competes with loss of water molecules for all V+(H2O)n, n ≤ 12. For n ≥ 15, no absorptions are observed, which indicates that the cluster ensemble is fully converted to HVOH+(H2O)n-1. For the smallest clusters, the electronic transitions are modeled using multireference methods with spin-orbit coupling. A large number of quintet and triplet states is accessible, which explains the broad features observed in the experiment. Water loss most likely occurs after a series of intersystem crossings and internal conversions to the electronic ground state or a low-lying quintet state, while hydrogen evolution is favored in low lying triplet states.
Collapse
Affiliation(s)
- Jakob Heller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Tobias F Pascher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Dominik Muß
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| |
Collapse
|
4
|
Marks JH, Miliordos E, Duncan MA. Infrared spectroscopy of RG-Co +(H 2O) complexes (RG = Ar, Ne, He): The role of rare gas "tag" atoms. J Chem Phys 2021; 154:064306. [PMID: 33588546 DOI: 10.1063/5.0041069] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
RGn-Co+(H2O) cation complexes (RG = Ar, Ne, He) are generated in a supersonic expansion by pulsed laser vaporization. Complexes are mass-selected using a time-of-flight spectrometer and studied with infrared laser photodissociation spectroscopy, measuring the respective mass channels corresponding to the elimination of the rare gas "tag" atom. Spectral patterns and theory indicate that the structures of the ions with a single rare gas atom have this bound to the cobalt cation opposite the water moiety in a near-C2v arrangement. The O-H stretch vibrations of the complex are shifted compared to those of water because of the metal cation charge-transfer interaction; these frequencies also vary systematically with the rare gas atom attached. The efficiencies of photodissociation also vary with the rare gas atoms because of their widely different binding energies to the cobalt cation. The spectrum of the argon complex could only be measured when at least three argon atoms were attached. In the case of the helium complex, the low binding energy allows the spectra to be measured for the low-frequency H-O-H scissors bending mode and for the O-D stretches of the deuterated analog. The partially resolved rotational structure for the antisymmetric O-H and O-D stretches reveals the temperature of these complexes (6 K) and establishes the electronic ground state. The helium complex has the same 3B1 ground state as the tag-free complex studied previously by Metz and co-workers ["Dissociation energy and electronic and vibrational spectroscopy of Co+(H2O) and its isotopomers," J. Phys. Chem. A 117, 1254 (2013)], but the A rotational constant is contaminated by vibrational averaging from the bending motion of the helium.
Collapse
Affiliation(s)
- Joshua H Marks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, USA
| | - Michael A Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| |
Collapse
|
5
|
Carnegie PD, Marks JH, Brathwaite AD, Ward TB, Duncan MA. Microsolvation in V +(H 2O) n Clusters Studied with Selected-Ion Infrared Spectroscopy. J Phys Chem A 2020; 124:1093-1103. [PMID: 31961153 DOI: 10.1021/acs.jpca.9b11275] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Gas-phase ion-molecule clusters of the form V+(H2O)n (n = 1-30) are produced by laser vaporization in a supersonic expansion. These ions are analyzed and mass-selected with a time-of-flight mass spectrometer and investigated with infrared laser photodissociation spectroscopy. The small clusters (n ≤ 7) are studied with argon tagging, while the larger clusters are studied via the elimination of water molecules. The vibrational spectra for the small clusters include only free O-H stretching vibrations, while larger clusters exhibit redshifted hydrogen bonding vibrations. The spectral patterns reveal that the coordination around V+ ions is completed with four water molecules. A symmetric square-planar structure forms for the n = 4 ion, and this becomes the core ion in larger structures. Clusters up to n = 8 have mostly two-dimensional structures, but hydrogen bonding networks evolve to three-dimensional structures in larger clusters. The free O-H vibration of acceptor-acceptor-donor (AAD)-coordinated surface molecules converges to a frequency near that of bulk water by the cluster size of n = 30. However, the splitting of this vibration for AAD- versus AD-coordinated molecules is still different compared to other singly charged or doubly charged cation-water clusters. This indicates that cation identity and charge-site location in the cluster can produce discernable spectral differences for clusters in this size range.
Collapse
Affiliation(s)
- Prosser D Carnegie
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - Joshua H Marks
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - Antonio D Brathwaite
- Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States
| | - Timothy B Ward
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - Michael A Duncan
- Department of Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| |
Collapse
|
6
|
Ariyarathna IR, Miliordos E. Geometric and electronic structure analysis of calcium water complexes with one and two solvation shells. Phys Chem Chem Phys 2020; 22:22426-22435. [DOI: 10.1039/d0cp04309e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The stability of calcium water complexes is investigated quantum mechanically. Ground and excited electronic states are studied for hexa-, octa-, and octakaideca-coordinated complexes, where calcium valence electrons move to outer diffuse orbitals.
Collapse
|
7
|
Chen Y, Jin J, Xin K, Yu W, Xing X, Wang X, Wang G. Infrared photodissociation spectroscopic studies of ScO(H2O)n=1–3Ar+ cluster cations: solvation induced reaction of ScO+ and water. Phys Chem Chem Phys 2019; 21:15639-15646. [DOI: 10.1039/c9cp02171j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate the gaseous ScO(H2O)1–3Ar+ cations prepared by laser vaporization coupled with supersonic molecular beam using infrared photodissociation spectroscopy in the O–H stretching region.
Collapse
Affiliation(s)
- Yinjuan Chen
- School of Chemical Science and Engineering
- Shanghai Key Lab of Chemical Assessment and Sustainability
- Tongji University
- Shanghai
- China
| | - Jiaye Jin
- Department of Chemistry
- Collaborative Innovation Center of Chemistry for Energy Materials
- Fudan University
- Shanghai 200438
- China
| | - Ke Xin
- School of Chemical Science and Engineering
- Shanghai Key Lab of Chemical Assessment and Sustainability
- Tongji University
- Shanghai
- China
| | - Wenjie Yu
- School of Chemical Science and Engineering
- Shanghai Key Lab of Chemical Assessment and Sustainability
- Tongji University
- Shanghai
- China
| | - Xiaopeng Xing
- School of Chemical Science and Engineering
- Shanghai Key Lab of Chemical Assessment and Sustainability
- Tongji University
- Shanghai
- China
| | - Xuefeng Wang
- School of Chemical Science and Engineering
- Shanghai Key Lab of Chemical Assessment and Sustainability
- Tongji University
- Shanghai
- China
| | - Guanjun Wang
- Department of Chemistry
- Collaborative Innovation Center of Chemistry for Energy Materials
- Fudan University
- Shanghai 200438
- China
| |
Collapse
|
8
|
Ariyarathna IR, Miliordos E. Superatomic nature of alkaline earth metal–water complexes: the cases of Be(H2O)0,+4 and Mg(H2O)0,+6. Phys Chem Chem Phys 2019; 21:15861-15870. [DOI: 10.1039/c9cp01897b] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Beryllium– and magnesium–water complexes are shown to accommodate peripheral electrons around their Be2+(H2O)4 and Mg2+(H2O)6 cores in hydrogenic type orbitals.
Collapse
|
9
|
Ončák M, Taxer T, Barwa E, van der Linde C, Beyer MK. Photochemistry and spectroscopy of small hydrated magnesium clusters Mg +(H 2O) n, n = 1-5. J Chem Phys 2018; 149:044309. [PMID: 30068190 PMCID: PMC7075709 DOI: 10.1063/1.5037401] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Hydrated singly charged magnesium ions Mg+(H2O)n, n ≤ 5, in the gas phase are ideal model systems to study photochemical hydrogen evolution since atomic hydrogen is formed over a wide range of wavelengths, with a strong cluster size dependence. Mass selected clusters are stored in the cell of an Fourier transform ion cyclotron resonance mass spectrometer at a temperature of 130 K for several seconds, which allows thermal equilibration via blackbody radiation. Tunable laser light is used for photodissociation. Strong transitions to D1-3 states (correlating with the 3s-3px,y,z transitions of Mg+) are observed for all cluster sizes, as well as a second absorption band at 4-5 eV for n = 3-5. Due to the lifted degeneracy of the 3px,y,z energy levels of Mg+, the absorptions are broad and red shifted with increasing coordination number of the Mg+ center, from 4.5 eV for n = 1 to 1.8 eV for n = 5. In all cases, H atom formation is the dominant photochemical reaction channel. Quantum chemical calculations using the full range of methods for excited state calculations reproduce the experimental spectra and explain all observed features. In particular, they show that H atom formation occurs in excited states, where the potential energy surface becomes repulsive along the O⋯H coordinate at relatively small distances. The loss of H2O, although thermochemically favorable, is a minor channel because, at least for the clusters n = 1-3, the conical intersection through which the system could relax to the electronic ground state is too high in energy. In some absorption bands, sequential absorption of multiple photons is required for photodissociation. For n = 1, these multiphoton spectra can be modeled on the basis of quantum chemical calculations.
Collapse
Affiliation(s)
- Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Thomas Taxer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Erik Barwa
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| |
Collapse
|
10
|
Ward TB, Miliordos E, Carnegie PD, Xantheas SS, Duncan MA. Ortho-para interconversion in cation-water complexes: The case of V+(H2O) and Nb+(H2O) clusters. J Chem Phys 2017; 146:224305. [DOI: 10.1063/1.4984826] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- T. B. Ward
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | - E. Miliordos
- Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, USA
| | - P. D. Carnegie
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | - S. S. Xantheas
- Advanced Computing, Mathematics and Data Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, USA
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| |
Collapse
|
11
|
Chen XY, Jin B, Cheng Y, Wang DS, Yang SH. Photodissociation Study of Ca+-Dipropylamine Complex. CHINESE J CHEM PHYS 2016. [DOI: 10.1063/1674-0068/29/cjcp1607137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
|
12
|
Ward T, Carnegie P, Duncan M. Infrared spectroscopy of the Ti(H2O)Ar+ ion–molecule complex: Electronic state switching induced by argon. Chem Phys Lett 2016. [DOI: 10.1016/j.cplett.2016.04.065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
13
|
Lam TW, Zhang H, Siu CK. Reductions of oxygen, carbon dioxide, and acetonitrile by the magnesium(II)/magnesium(I) couple in aqueous media: theoretical insights from a nano-sized water droplet. J Phys Chem A 2015; 119:2780-92. [PMID: 25738586 DOI: 10.1021/jp511490n] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Reductions of O2, CO2, and CH3CN by the half-reaction of the Mg(II)/Mg(I) couple (Mg(2+) + e(-) → Mg(+•)) confined in a nanosized water droplet ([Mg(H2O)16](•+)) have been examined theoretically by means of density functional theory based molecular dynamics methods. The present works have revealed many intriguing aspects of the reaction dynamics of the water clusters within several picoseconds or even in subpicoseconds. The reduction of O2 requires an overall doublet spin state of the system. The reductions of CO2 and CH3CN are facilitated by their bending vibrations and the electron-transfer processes complete within 0.5 ps. For all reactions studied, the radical anions, i.e., O2(•-), CO2(•-), and CH3CN(•-), are initially formed on the cluster surface. O2(•-) and CO2(•-) can integrate into the clusters due to their high hydrophilicity. They are either solvated in the second solvation shell of Mg(2+) as a solvent-separated ion pair (ssip) or directly coordinated to Mg(2+) as a contact-ion pair (cip) having the (1)η-[MgO2](•+) and (1)η-[MgOCO](•+) coordination modes. The (1)η-[MgO2](•+) core is more crowded than the (1)η-[MgOCO](•+) core. The reaction enthalpies of the formation of ssip and cip of [Mg(CO2)(H2O)16](•+) are -36 ± 4 kJ mol(-1) and -30 ± 9 kJ mol(-1), respectively, which were estimated based on the average temperature changes during the ion-molecule reaction between CO2 and [Mg(H2O)16](•+). The values for the formation of ssip and cip of [Mg(O2)(H2O)16](•+) are estimated to be -112 ± 18 kJ mol(-1) and -128 ± 28 kJ mol(-1), respectively. CH3CN(•-) undergoes protonation spontaneously to form the hydrophobic [CH3CN, H](•). Both CH3CN and [CH3CN, H](•) cannot efficiently penetrate into the clusters with activation barriers of 22 kJ mol(-1) and ∼40 kJ mol(-1), respectively. These results provide fundamental insights into the solvation dynamics of the Mg(2+)/Mg(•+) couple on the molecular level.
Collapse
Affiliation(s)
- Tim-Wai Lam
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, P. R. China
| | - Han Zhang
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, P. R. China
| | - Chi-Kit Siu
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong SAR, P. R. China
| |
Collapse
|
14
|
Bandyopadhyay B, Reishus KN, Duncan MA. Infrared spectroscopy of solvation in small Zn+ (H2O)n complexes. J Phys Chem A 2013; 117:7794-803. [PMID: 23875934 DOI: 10.1021/jp4046676] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Singly charged zinc-water cations are produced in a pulsed supersonic expansion source using laser vaporization. Zn(+)(H2O)n (n = 1-4) complexes are mass selected and studied with infrared laser photodissociation spectroscopy, employing the method of argon tagging. Density functional theory (DFT) computations are used to obtain the structures and vibrational frequencies of these complexes and their isomers. Spectra in the O-H stretching region show sharp bands corresponding to the symmetric and asymmetric stretches, whose frequencies are lower than those in the isolated water molecule. Zn(+)(H2O)nAr complexes with n = 1-3 have O-H stretches only in the higher frequency region, indicating direct coordination to the metal. The Zn(+)(H2O)2-4Ar complexes have multiple bands here, indicating the presence of multiple low energy isomers differing in the attachment position of argon. The Zn(+)(H2O)4Ar cluster uniquely exhibits a broad band in the hydrogen bonded stretch region, indicating the presence of a second sphere water molecule. The coordination of the Zn(+)(H2O)n complexes is therefore completed with three water molecules.
Collapse
|
15
|
Lam TW, van der Linde C, Akhgarnusch A, Hao Q, Beyer MK, Siu CK. Reduction of Acetonitrile by Hydrated Magnesium Cations Mg + (H 2 O) n (n≈20-60) in the Gas Phase. Chempluschem 2013; 78:1040-1048. [PMID: 31986721 DOI: 10.1002/cplu.201300170] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Indexed: 11/09/2022]
Abstract
Ion-molecule reactions of Mg+ (H2 O)n (n≈20-60) with CH3 CN are studied by Fourier-transform ion-cyclotron resonance mass spectrometry. Collision with CH3 CN initiates the formation of MgOH+ (H2 O)n-1 together with CH3 CHN. or CH3 CNH. , which is similar to the reaction of hydrated electrons (H2 O)n - with CH3 CN. In subsequent reaction steps, three more CH3 CN molecules are taken up by the clusters, to form MgOH+ (CH3 CN)3 after a reaction delay of 60 seconds. Density functional theory (DFT) calculations at the M06/6-31++G(d,p) level of theory suggest that the bending motion of CH3 CN allows the unpaired electron that is solvated out from the Mg center to localize in a π*(CN)-like orbital of the bent CH3 CN.- , which undergoes spontaneous proton transfer to form CH3 CNH. or CH3 CHN. , with the former being kinetically more favorable. The reaction energy for a cluster with the hexacoordinated Mg center is more exothermic than that with the pentacoordinated Mg. The CH3 CNH. or CH3 CHN. is preferentially solvated on the cluster surface rather than at the first solvation shell of the Mg center. By contrast, the three additional CH3 CN molecules taken up by the resulting MgOH+ (H2 O)n clusters coordinate directly to the first solvation shell of the MgOH+ core, as revealed by DFT calculations.
Collapse
Affiliation(s)
- Tim-Wai Lam
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong (P. R. China), Fax: (+852) 3442-0522
| | - Christian van der Linde
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098 Kiel (Germany), Fax: (+49) 431-880-2830
| | - Amou Akhgarnusch
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098 Kiel (Germany), Fax: (+49) 431-880-2830
| | - Qiang Hao
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong (P. R. China), Fax: (+852) 3442-0522
| | - Martin K Beyer
- Institut für Physikalische Chemie, Christian-Albrechts-Universität zu Kiel, Olshausenstraße 40, 24098 Kiel (Germany), Fax: (+49) 431-880-2830
| | - Chi-Kit Siu
- Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong (P. R. China), Fax: (+852) 3442-0522
| |
Collapse
|
16
|
Cabanillas-Vidosa I, Rossa M, Pino GA, Ferrero JC, Cobos CJ. Hydration of Barium Monohydroxide in (H2O)1–3 Clusters: Theory and Experiment. J Phys Chem A 2013; 117:4997-5006. [DOI: 10.1021/jp312678s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iván Cabanillas-Vidosa
- Instituto
de Investigaciones
Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Casilla de Correo
16, Sucursal 4, La Plata (1900), Argentina
| | - Maximiliano Rossa
- Centro Láser de Ciencias
Moleculares, INFIQC, Departamento de Fisicoquímica, Facultad
de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba (X5000IUS), Argentina
| | - Gustavo A. Pino
- Centro Láser de Ciencias
Moleculares, INFIQC, Departamento de Fisicoquímica, Facultad
de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba (X5000IUS), Argentina
| | - Juan C. Ferrero
- Centro Láser de Ciencias
Moleculares, INFIQC, Departamento de Fisicoquímica, Facultad
de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba (X5000IUS), Argentina
| | - Carlos J. Cobos
- Instituto
de Investigaciones
Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Casilla de Correo
16, Sucursal 4, La Plata (1900), Argentina
| |
Collapse
|
17
|
Structural and Infra Red Spectroscopic Aspects of Ion-Water Clusters: A Study Based on a Combined Stochastic and Quantum Chemical Approach. J CLUST SCI 2013. [DOI: 10.1007/s10876-013-0565-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
18
|
Li Y, Wang G, Wang C, Zhou M. Coordination and Solvation of the Au+ Cation: Infrared Photodissociation Spectroscopy of Mass-Selected Au(H2O)n+ (n = 1–8) Complexes. J Phys Chem A 2012; 116:10793-801. [DOI: 10.1021/jp3094963] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yuzhen Li
- Department of Chemistry, Shanghai
Key Laboratory of
Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Guanjun Wang
- Department of Chemistry, Shanghai
Key Laboratory of
Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Caixia Wang
- Department of Chemistry, Shanghai
Key Laboratory of
Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| | - Mingfei Zhou
- Department of Chemistry, Shanghai
Key Laboratory of
Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433, China
| |
Collapse
|
19
|
Neogi SG, Chaudhury P. Structure and spectroscopic aspects of water-halide ion clusters: A study based on a conjunction of stochastic and quantum chemical methods. J Comput Chem 2012; 34:471-91. [DOI: 10.1002/jcc.23156] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/01/2012] [Accepted: 09/07/2012] [Indexed: 01/17/2023]
|
20
|
Duncan MA. Invited review article: laser vaporization cluster sources. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:041101. [PMID: 22559508 DOI: 10.1063/1.3697599] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The laser vaporization cluster source has been used for the production of gas phase atomic clusters and metal-molecular complexes for 30 years. Numerous experiments in the chemistry and physics of clusters have employed this source. Its operation is simple in principle, but there are many subtle design features that influence the number and size of clusters produced, as well as their composition, charge state, and temperature. This article examines all aspects of the design of these cluster sources, discussing the relevant chemistry, physics, and mechanical aspects of experimental configurations employed by different labs. The principles detailed here provide a framework for the design and implementation of this source for new applications.
Collapse
Affiliation(s)
- Michael A Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA.
| |
Collapse
|
21
|
|
22
|
Cabanillas-Vidosa I, Rossa M, Pino GA, Ferrero JC, Cobos CJ. Photoionization and ab initio study of Ba(H2O)n (n = 1–4) clusters. Phys Chem Chem Phys 2012; 14:4276-86. [DOI: 10.1039/c2cp23510b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
23
|
|
24
|
Cabanillas-Vidosa I, Rossa M, Pino GA, Ferrero JC. Unexpected size distribution of Ba(H2O)n clusters: why is the intensity of the Ba(H2O)1 cluster anomalously low? Phys Chem Chem Phys 2011; 13:13387-94. [PMID: 21701713 DOI: 10.1039/c0cp02881a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An experimental and theoretical study on the reactivity of neutral Ba atoms with water clusters has been conducted to unravel the origin of the irregular intensity pattern observed in one-photon ionization mass spectra of a Ba(H(2)O)(n)/BaOH(H(2)O)(n-1) (n = 1-4) cluster distribution, which was generated in a laser vaporization-supersonic expansion source. The most remarkable irregular feature is the finding for n = 1 of a lower intensity for the Ba(+)(H(2)O)(n) peak with respect to that of BaOH(+)(H(2)O)(n-1), which is opposite to the trend for n = 2-4. Rationalization of the data required consideration of a distinct behavior of ground-state and electronically excited state Ba atoms in inelastic and reactive Ba + (H(2)O)(n) encounters that can occur in the cluster source. Within this picture, the generation of Ba(H(2)O)(n) (n > 1) association products results from stabilizing collisions with atoms of the carrier gas, which are favored by intramolecular vibrational redistribution that operates on the corresponding collision intermediates prior to stabilization; the latter is unlikely to occur for Ba + (H(2)O) encounters. Overall, this interpretation is consistent with additional in-source laser excitation and quenching experiments, which aimed to explore qualitatively the effect of perturbing the Ba atom electronic state population distribution on the observed intensity pattern, as well as with the energetics of various possible reactions for the Ba + H(2)O system that derive from high level ab initio calculations.
Collapse
Affiliation(s)
- Iván Cabanillas-Vidosa
- Centro Láser de Ciencias Moleculares, INFIQC and Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, X5000IUS Córdoba, Argentina
| | | | | | | |
Collapse
|
25
|
Carnegie PD, Bandyopadhyay B, Duncan MA. Infrared spectroscopy of Mn+ (H2O) and Mn2+ (H2O) via argon complex predissociation. J Phys Chem A 2011; 115:7602-9. [PMID: 21619058 DOI: 10.1021/jp203501n] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Singly and doubly charged manganese-water cations, and their mixed complexes with attached argon atoms, are produced by laser vaporization in a pulsed nozzle source. Complexes of the form Mn(+)(H(2)O)Ar(n) (n = 1-4) and Mn(2+)(H(2)O)Ar(4) are studied via mass-selected infrared photodissociation spectroscopy, detected in the mass channels corresponding to the elimination of argon. Sharp resonances are detected for all complexes in the region of the symmetric and asymmetric stretch vibrations of water. With the guidance of density functional theory computations, specific vibrational band resonances are assigned to complexes having different argon attachment configurations. In the small singly charged complexes, argon adds first to the metal ion site and later in larger clusters to the hydrogens of water. The doubly charged complex has argon only on the metal ion. Vibrations in all of these complexes are shifted to lower frequencies than those of the free water molecule. These shifts are greater when argon is attached to hydrogen and also greater for the dication compared to the singly charged species. Cation binding also causes the IR intensities for water vibrations to be much greater than those of the free water molecule, and the relative intensities are greater for the symmetric stretch than the asymmetric stretch. This latter effect is also enhanced for the dication complex.
Collapse
Affiliation(s)
- P D Carnegie
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, United States
| | | | | |
Collapse
|
26
|
Puskar L, Stace AJ. UV photofragmentation of gas phase M and M2 complexes with ketones, where M = Cu and Ag. Mol Phys 2011. [DOI: 10.1080/00268970500062691] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- L. Puskar
- a Department of Chemistry , University of Sussex , Falmer, Brighton , BN1 9QJ , UK
| | - A. J. Stace
- a Department of Chemistry , University of Sussex , Falmer, Brighton , BN1 9QJ , UK
| |
Collapse
|
27
|
Carnegie PD, Bandyopadhyay B, Duncan MA. Infrared spectroscopy of Sc+(H2O) and Sc2+(H2O) via argon complex predissociation: The charge dependence of cation hydration. J Chem Phys 2011; 134:014302. [DOI: 10.1063/1.3515425] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
28
|
Duncan MA. Infrared spectroscopy to probe structure and dynamics in metal ion-molecule complexes. INT REV PHYS CHEM 2010. [DOI: 10.1080/0144235031000095201] [Citation(s) in RCA: 280] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Michael A. Duncan
- a Department of Chemistry , University of Georgia , Athens , GA , 30602-2556 , USA
| |
Collapse
|
29
|
Fox-Beyer BS, Sun Z, Balteanu I, Balaj OP, Beyer MK. Hydrogen formation in the reaction of Zn+ (H2O)n with HCl. Phys Chem Chem Phys 2009; 7:981-5. [PMID: 19791389 DOI: 10.1039/b415583a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrated singly charged zinc cations Zn (H2O)n, n approximately 6-53, were studied by Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. Black-body radiation induced dissociation results exclusively in sequential loss of individual water molecules. In the reaction of Zn+ (H2O)n with gaseous HCl, Zn is oxidized and hydrogen reduced when a second HCl molecule is taken up, leading to the formation of ZnCl+ (HCl)(H2O)n-m cluster ions and evaporation of atomic hydrogen together with m H2O molecules. The results are compared with earlier studies of Mg+ (H2O)n, for which hydrogen formation is already observed without HCl in a characteristic size region. The difference between zinc and magnesium is rationalized with the help of density functional theory calculations, which indicate a distinct difference in the thermochemistry of the reactions involved. The generally accepted hydrated electron model for hydrogen formation in Mg+ (H2O)n is modified for zinc to account for the different reactivity.
Collapse
Affiliation(s)
- Brigitte S Fox-Beyer
- Department Chemie, Physikalische Chemie 2, Technische Universität München, Lichtenbergstr. 4, D-85747 Garching, Germany.
| | | | | | | | | |
Collapse
|
30
|
Donald WA, Leib RD, O’Brien JT, Williams ER. Directly relating gas-phase cluster measurements to solution-phase hydrolysis, the absolute standard hydrogen electrode potential, and the absolute proton solvation energy. Chemistry 2009; 15:5926-34. [PMID: 19440999 PMCID: PMC2757329 DOI: 10.1002/chem.200900334] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Solution-phase, half-cell potentials are measured relative to other half-cell potentials, resulting in a thermochemical ladder that is anchored to the standard hydrogen electrode (SHE), which is assigned an arbitrary value of 0 V. A new method for measuring the absolute SHE potential is demonstrated in which gaseous nanodrops containing divalent alkaline-earth or transition-metal ions are reduced by thermally generated electrons. Energies for the reactions 1) M(H(2)O)(24)(2+)(g) + e(-)(g)-->M(H(2)O)(24)(+)(g) and 2) M(H(2)O)(24)(2+)(g) + e(-)(g)-->MOH(H(2)O)(23)(+)(g) + H(g) and the hydrogen atom affinities of MOH(H(2)O)(23)(+)(g) are obtained from the number of water molecules lost through each pathway. From these measurements on clusters containing nine different metal ions and known thermochemical values that include solution hydrolysis energies, an average absolute SHE potential of +4.29 V vs. e(-)(g) (standard deviation of 0.02 V) and a real proton solvation free energy of -265 kcal mol(-1) are obtained. With this method, the absolute SHE potential can be obtained from a one-electron reduction of nanodrops containing divalent ions that are not observed to undergo one-electron reduction in aqueous solution.
Collapse
Affiliation(s)
- William A. Donald
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460 (USA), Fax: (+1) 510-642-7714
| | - Ryan D. Leib
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460 (USA), Fax: (+1) 510-642-7714
| | - Jeremy T. O’Brien
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460 (USA), Fax: (+1) 510-642-7714
| | - Evan R. Williams
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720-1460 (USA), Fax: (+1) 510-642-7714
| |
Collapse
|
31
|
Hashimoto K, Daigoku K. Ground and low-lying excited states of Na(NH3)n and Na(H2O)n clusters: Formation and localization of solvated electron. Chem Phys Lett 2009. [DOI: 10.1016/j.cplett.2008.12.079] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
32
|
Hashimoto K, Daigoku K. Formation and localization of a solvated electron in ground and low-lying excited states of Li(NH3)n and Li(H2O)n clusters: a comparison with Na(NH3)n and Na(H2O)n. Phys Chem Chem Phys 2009; 11:9391-400. [DOI: 10.1039/b907766a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
|
33
|
Carnegie PD, Bandyopadhyay B, Duncan MA. Infrared spectroscopy of Cr+(H2O) and Cr2+(H2O): the role of charge in cation hydration. J Phys Chem A 2008; 112:6237-43. [PMID: 18563888 DOI: 10.1021/jp803086v] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Singly and doubly charged chromium-water ion-molecule complexes are produced by laser vaporization in a pulsed-nozzle cluster source. These species are detected and mass-selected in a specially designed time-of-flight mass spectrometer. Vibrational spectroscopy is measured for these complexes in the O-H stretching region using infrared photodissociation spectroscopy and the method of rare gas atom predissociation. Infrared excitation is not able to break the ion-water bonds in these systems, but it leads to elimination of argon, providing an efficient mechanism for detecting the spectrum. The O-H stretches for both singly and doubly charged complexes are shifted to frequencies lower than those for the free water molecule, and the intensity of the symmetric stretch band is strongly enhanced relative to the asymmetric stretch. Partially resolved rotational structure for both complexes shows that the H-O-H bond angle is greater than it is in the free water molecule. These polarization-induced effects are enhanced in the doubly charged ion relative to its singly charged analog.
Collapse
Affiliation(s)
- P D Carnegie
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | | | | |
Collapse
|
34
|
Abstract
Studying metal ion solvation, especially hydration, in the gas phase has developed into a field that is dominated by a tight interaction between experiment and theory. Since the studied species carry charge, mass spectrometry is an indispensable tool in all experiments. Whereas gas-phase coordination chemistry and reactions of bare metal ions are reasonably well understood, systems containing a larger number of solvent molecules are still difficult to understand. This review focuses on the rich chemistry of hydrated metal ions in the gas phase, covering coordination chemistry, charge separation in multiply charged systems, as well as intracluster and ion-molecule reactions. Key ideas of metal ion solvation in the gas phase are illustrated with rare-gas solvated metal ions.
Collapse
Affiliation(s)
- Martin K Beyer
- Institut für Chemie, Sekr. C4, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany.
| |
Collapse
|
35
|
Walker NR, Walters RS, Tsai MK, Jordan KD, Duncan MA. Infrared photodissociation spectroscopy of Mg(+)(H2O)Ar(n) complexes: isomers in progressive microsolvation. J Phys Chem A 2007; 109:7057-67. [PMID: 16834068 DOI: 10.1021/jp051877t] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ion-molecule complexes of the form Mg(H2O)Ar(n)+ (n = 1-8) are produced by laser vaporization in a pulsed-nozzle cluster source. These complexes are mass-selected and studied with infrared photodissociation spectroscopy in the O-H stretch region. The spectra are interpreted with the aid of ab initio calculations on the n = 1-5 complexes, including examination of various isomeric structures. The combined spectroscopic and theoretical studies reveal the presence of multiple isomeric structures at each cluster size, as the argon atoms assemble around the Mg(+)(H2O) unit. Distinct infrared resonances are measured for argon-on-metal, argon-on-OH and argon-on-two-OH isomers.
Collapse
Affiliation(s)
- N R Walker
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | | | | | | | | |
Collapse
|
36
|
Kasalova V, Allen WD, Schaefer HF, Pillai ED, Duncan MA. Model Systems for Probing Metal Cation Hydration: The V+(H2O) and ArV+(H2O) Complexes. J Phys Chem A 2007; 111:7599-610. [PMID: 17511435 DOI: 10.1021/jp071206q] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In support of mass-selected infrared photodissociation (IRPD) spectroscopy experiments, coupled-cluster methods including all single and double excitations (CCSD) and a perturbative contribution from connected triple excitations [CCSD(T)] have been used to study the V+(H2O) and ArV+(H2O) complexes. Equilibrium geometries, harmonic vibrational frequencies, and dissociation energies were computed for the four lowest-lying quintet states (5A1, 5A2, 5B1, and 5B2), all of which appear within a 6 kcal mol(-1) energy range. Moreover, anharmonic vibrational analyses with complete quartic force fields were executed for the 5A1 states of V+(H2O) and ArV+(H2O). Two different basis sets were used: a Wachters+f V[8s6p4d1f] basis with triple-zeta plus polarization (TZP) for O, H, and Ar; and an Ahlrichs QZVPP V[11s6p5d3f2g] and Ar[9s6p4d2f1g] basis with aug-cc-pVQZ for O and H. The ground state is predicted to be 5A1 for V+(H2O), but argon tagging changes the lowest-lying state to 5B1 for ArV+(H2O). Our computations show an opening of 2 degrees -3 degrees in the equilibrium bond angle of H2O due to its interaction with the metal ion. Zero-point vibrational averaging increases the effective bond angle further by 2.0 degrees -2.5 degrees, mostly because of off-axis motion of the heavy vanadium atom rather than changes in the water bending potential. The total theoretical shift in the bond angle of about +4 degrees is significantly less than the widening near 9 degrees deduced from IRPD experiments. The binding energies (D0) for the successive addition of H2O and Ar to the vanadium cation are 36.2 and 9.4 kcal mol(-1), respectively.
Collapse
Affiliation(s)
- Veronika Kasalova
- Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525, USA
| | | | | | | | | |
Collapse
|
37
|
Structures, Spectroscopies, and Reactions of Atomic Ions with Water Clusters. ADVANCES IN CHEMICAL PHYSICS 2007. [DOI: 10.1002/9780470141694.ch7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
38
|
Hashimoto K, Shimizu T, Daigoku K. Electronic States of Sodium Dimer in Ammonia Clusters: Theoretical Study of Photoelectron Spectra for Na2-(NH3)n (n = 0−6). J Phys Chem A 2007; 111:1990-7. [PMID: 17388273 DOI: 10.1021/jp0652188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The geometries, energetics, and vertical detachment energies of Na2-(NH3)n (n = 0-6) were examined by ab initio molecular orbital methods in connection with their photoelectron spectra. One of the Na atoms is selectively solvated in the most stable structures for each n. The solvated Na is spontaneously ionized and the formation of a solvated electron occurs with increasing n, giving rise to the Na-Na+(NH3)n(e-)-type state. The ground and two lowest-lying excited states derived from the 11Sigma g+, 13Sigma u+, and 13Pi u states of Na2, respectively, are of ion-pair character though the 13Sigma u+-type state has an intermediate nature slowly changing to the radical-pair state with increasing n. On the other hand, the higher states stemming from the 11Sigma u+, 13Sigma g+, and 11Pi u states of Na2 show a developing radical-pair nature as n increases. The size dependences of the photoelectron spectra such as the near parallel shifts of the first and second bands, as well as the rapid red shifts of the higher bands, are studied on the basis of the electronic change of the neutrals by solvation.
Collapse
Affiliation(s)
- Kenro Hashimoto
- Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami-Ohsawa, Hachioji, Tokyo 192-0397, Japan.
| | | | | |
Collapse
|
39
|
|
40
|
Salter TE, Mikhailov VA, Evans CJ, Ellis AM. Infrared spectroscopy of Li(NH3)n clusters for n=4–7. J Chem Phys 2006; 125:34302. [PMID: 16863345 DOI: 10.1063/1.2208349] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Infrared spectra of Li(NH3)(n) clusters as a function of size are reported for the first time. Spectra have been recorded in the N-H stretching region for n=4-->7 using a mass-selective photodissociation technique. For the n=4 cluster, three distinct IR absorption bands are seen over a relatively narrow region, whereas the larger clusters yield additional features at higher frequencies. Ab initio calculations have been carried out in support of these experiments for the specific cases of n=4 and 5 for various isomers of these clusters. The bands observed in the spectrum for Li(NH3)(4) can all be attributed to N-H stretching vibrations from solvent molecules in the first solvation shell. The appearance of higher frequency N-H stretching bands for n > or =5 is assigned to the presence of ammonia molecules located in a second solvent shell. These data provide strong support for previous suggestions, based on gas phase photoionization measurements, that the first solvation shell for Li(NH3)(n) is complete at n=4. They are also consistent with neutron diffraction studies of concentrated lithium/liquid ammonia solutions, where Li(NH3)(4) is found to be the basic structural motif.
Collapse
Affiliation(s)
- Tom E Salter
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom
| | | | | | | |
Collapse
|
41
|
Walters RS, Pillai ED, Duncan MA. Solvation dynamics in Ni+ (H2O)n clusters probed with infrared spectroscopy. J Am Chem Soc 2006; 127:16599-610. [PMID: 16305249 DOI: 10.1021/ja0542587] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared photodissociation spectroscopy is reported for mass-selected Ni+ (H2O)n complexes in the O-H stretching region up to cluster sizes of n = 25. These clusters fragment by the loss of one or more intact water molecules, and their excitation spectra show distinct bands in the region of the symmetric and asymmetric stretches of water. The first evidence for hydrogen bonding, indicated by a broad band strongly red-shifted from the free OH region, appears at the cluster size of n = 4. At larger cluster sizes, additional red-shifted structure evolves over a broader wavelength range in the hydrogen-bonding region. In the free OH region, the symmetric stretch gradually diminishes in intensity, while the asymmetric stretch develops into a closely spaced doublet near 3700 cm(-1). The data indicate that essentially all of the water molecules are in a hydrogen-bonded network by the size of n = 10. However, there is no evidence for the formation of clathrate structures seen recently via IR spectroscopy of protonated water clusters.
Collapse
Affiliation(s)
- Richard S Walters
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
| | | | | |
Collapse
|
42
|
Velasquez J, Pillai ED, Carnegie PD, Duncan MA. IR Spectroscopy of M+(Acetone) Complexes (M = Mg, Al, Ca): Cation−Carbonyl Binding Interactions. J Phys Chem A 2006; 110:2325-30. [PMID: 16480290 DOI: 10.1021/jp0574899] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
M(+)(acetone) ion-molecule complexes (M = Mg, Al, Ca) are produced in a pulsed molecular beam by laser vaporization and studied with infrared photodissociation spectroscopy in the carbonyl stretch region. All of the spectra exhibit carbonyl stretches that are shifted significantly to lower frequencies than the free-molecule value, consistent with metal cation binding on the oxygen of the carbonyl. Density functional theory is employed to elucidate the shifts and patterns in these spectra. Doublet features are measured for the carbonyl region of Mg(+) and Ca(+) complexes, and these are assigned to Fermi resonances between the symmetric carbonyl stretch and the overtone of the symmetric carbon stretch. The carbonyl stretch red shift is greater for Al(+) than it is for the Mg(+) and Ca(+) complexes. This is attributed to the smaller size of the closed-shell Al(+), which enhances its ability to polarize the carbonyl electrons. Density functional theory correctly predicts the direction of the carbonyl stretch shift and the relative trend for the three metals.
Collapse
|
43
|
Liu H, Hu Y, Yang S, Guo W, Lu X, Zhao L. Experimental and Computational Studies of Intracomplex Reactions in Mg+(Primary, Secondary Alkylamine) Complexes Induced by Photoexcitation of Mg+. Chemistry 2005; 11:6392-406. [PMID: 16086333 DOI: 10.1002/chem.200401325] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We report herein a comprehensive study of photoinduced reactions in complexes of Mg+ with primary (n-propyl- and isopropylamine) and secondary amines (dipropyl- and diisopropylamine) in the spectral range of 230-440 nm. Similar to the methyl- and ethylamine complexes studied previously, N-H bond activation of these complexes is very unfavorable. Instead, the C(alpha)-C, C-N, and C(alpha)-H bond-cleavage photoproducts are observed after photoexcitation of the Mg+ complexes (3(2)P<--3(2)S). For Mg+(primary amine) complexes, for example, Mg+-NH2CH2CH2CH3, and Mg+-NH2CH(CH3)2, the photoproducts resulting from C(alpha)--C rupture prevail after P(z) and charge-transfer excitations, whereas the Mg+ photofragment is predominant upon P(x,y) excitation. However, with further N-alkyl substitution, as in Mg+(secondary amine) complexes, for example, Mg+-NH(CH2CH2CH3)2 and Mg+-NH[CH(CH3)2]2, a novel intracomplex C-C coupling photoreaction dominates on P(x,y) excitation of Mg+, which is believed to arise from Mg+* insertion into the C-N bond. With P(z) and charge-transfer excitation, the Mg-R elimination photoproducts, arising from C(alpha)-C bond cleavage, predominate. The energetics and possible mechanisms of the intracomplex photoreactions are analyzed in detail with the help of extensive quantum mechanics calculations.
Collapse
Affiliation(s)
- Haichuan Liu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, PR China
| | | | | | | | | | | |
Collapse
|
44
|
|
45
|
Abate Y, Kleiber PD. Photodissociation spectroscopy of Zn+(H2O) and Zn+(D2O). J Chem Phys 2005; 122:84305. [PMID: 15836037 DOI: 10.1063/1.1847610] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
We report on a study of the photodissociation spectroscopy of weakly bound Zn+(H2O) and Zn+(D2O) complexes. The work is supported by ab initio electronic structure calculations of the ground and low-lying excited energy surfaces. We assign two molecular absorption bands in the near UV correlating to Zn+ (4s-4p)-based transitions, and identify vibrational progressions associated with both intermolecular and intramolecular vibrational modes of the cluster. Partially resolved rotational structure is consistent with a C(2V) equilibrium complex geometry. Experimental spectroscopic constants are in very good agreement with ab initio theoretical predictions. Results are compared with previous work on main group and transition metal ion-H2O clusters.
Collapse
Affiliation(s)
- Y Abate
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52242, USA
| | | |
Collapse
|
46
|
Okai N, Yoshida S, Aranishi K, Takahata A, Fuke K. Multiphoton ionization and oxidation processes of Mg–ammonia clusters. Phys Chem Chem Phys 2005; 7:921-9. [DOI: 10.1039/b415964k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
47
|
Sun JL, Liu H, Yin HM, Han KL, Yang S. Photodissociation of Solvated Metal Cation Complexes Mg+(OCNC2H5)n (n = 1−3). J Phys Chem A 2004. [DOI: 10.1021/jp0380529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Ju-Long Sun
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, 116023 Dalian, China
| | - Haichuan Liu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, 116023 Dalian, China
| | - Hong-Ming Yin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, 116023 Dalian, China
| | - Ke-Li Han
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, 116023 Dalian, China
| | - Shihe Yang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China, and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, 116023 Dalian, China
| |
Collapse
|
48
|
Lee JI, Sperry DC, Farrar JM. Spectroscopy and reactivity of size-selected Mg[sup +]-ammonia clusters. J Chem Phys 2004; 121:8375-84. [PMID: 15511158 DOI: 10.1063/1.1802498] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Photodissociation spectra for mass-selected Mg(+)(NH(3))(n) clusters for n=1 to 7 are reported over the photon energy range from 7000 to 38 500 cm(-1). The singly solvated cluster, which dissociates primarily via a N-H bond cleavage, exhibits a resolved vibrational structure corresponding to two progressions in the intracluster Mg(+)-NH(3) modes. The addition of the second, third, and fourth solvent molecules results in monotonic redshifts that appear to halt near 8500 cm(-1), where a sharp feature in the electronic spectrum is correlated with the formation of a Mg(+)(NH(3))(4) complex with T(d) symmetry and the closing of the first solvation shell. The spectra for the clusters with 5 to 7 solvent molecules strongly resemble that for the tetramer, suggesting that these solvent molecules occupy a second solvation shell. The wavelength-dependent branching-ratio measurements show that increasing the photon energies generally result in the loss of additional solvent molecules but that enhancements for a specific solvent number loss may reveal special stability for the resultant fragments. The majority of the experimental evidence suggests that the decay of these clusters occurs via the internal conversion of the initially excited electronic states to the ground state, followed by dissociation. In the case of the monomer, the selective cleavage of a N-H bond in the solvent suggests that this internal-conversion process may populate regions of the ground-state surface in the vicinity of an insertion complex H-Mg(+)-NH(2), whose existence is predicted by ab initio calculations.
Collapse
Affiliation(s)
- James I Lee
- Department of Chemistry, University of Rochester, Rochester, NY 14627-0216, USA
| | | | | |
Collapse
|
49
|
Schulz CP, Bobbert C, Shimosato T, Daigoku K, Miura N, Hashimoto K. Electronically excited states of sodium–water clusters. J Chem Phys 2003. [DOI: 10.1063/1.1624599] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
50
|
Liu H, Hu Y, Yang S. Photodissociation Studies of Mass-Selected Complex Cations Mg +( N, N-dimethylformamide) 1,2. J Phys Chem A 2003. [DOI: 10.1021/jp036110k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Haichuan Liu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yihua Hu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Shihe Yang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| |
Collapse
|