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Mai NT, Ngo ST, Lievens P, Janssens E, Thanh Tung N. Photofragmentation Patterns of Cobalt Oxide Cations Co nO m+ ( n = 5–9, m = 4–13): From Oxygen-Deficient to Oxygen-Rich Species. J Phys Chem A 2020; 124:7333-7339. [DOI: 10.1021/acs.jpca.0c01545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nguyen Thi Mai
- Institute of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology,10307 Hanoi, Vietnam
| | - Son Tung Ngo
- Faculty of Applied Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Peter Lievens
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, 3001 Leuven, Belgium
| | - Ewald Janssens
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, 3001 Leuven, Belgium
| | - Nguyen Thanh Tung
- Institute of Materials Science and Graduate University of Science and Technology, Vietnam Academy of Science and Technology,10307 Hanoi, Vietnam
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2
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Lasserus M, Schnedlitz M, Messner R, Lackner F, Ernst WE, Hauser AW. Vanadium(V) oxide clusters synthesized by sublimation from bulk under fully inert conditions. Chem Sci 2019; 10:3473-3480. [PMID: 30996937 PMCID: PMC6432649 DOI: 10.1039/c8sc05699d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/23/2019] [Indexed: 12/01/2022] Open
Abstract
While laser ablation in combination with electron impact mass spectroscopy yield numerous fragments and reaction products, helium-mediated mass analysis reveals the sublimation from bulk in units of (V2O5)2.
Oxide nanoparticles in the size range of a few nanometers are typically synthesized in solution or via laser ablation techniques, which open numerous channels for structural change via chemical reactions or fragmentation processes. In this work, neutral vanadium oxide nanoparticles are instead synthesized by sublimation from bulk in combination with a pickup by superfluid helium droplets. Mass spectroscopy measurements clearly demonstrate the preservation of the bulk stoichiometric ratio of vanadium to oxygen in He-grown nanoparticles, indicating a tendency towards tetrahedral coordination of the vanadium centers in finite geometries. This unexpected finding opens up new possibilities for a combined on-the-fly synthesis of nanoparticles consisting of metal and metal-oxide layers. In comparison to mass spectra obtained via direct ionization of vanadium oxide in an effusive beam, where strong fragmentation occurred, we observe a clear preference for (V2O5)n oligomers with even n inside the He nanodroplets, which is further investigated and explained using the electronic structure theory.
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Affiliation(s)
- Maximilian Lasserus
- Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria . ; ; ; Tel: +43 316 873 8157 ; Tel: +43 316 873 8140
| | - Martin Schnedlitz
- Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria . ; ; ; Tel: +43 316 873 8157 ; Tel: +43 316 873 8140
| | - Roman Messner
- Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria . ; ; ; Tel: +43 316 873 8157 ; Tel: +43 316 873 8140
| | - Florian Lackner
- Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria . ; ; ; Tel: +43 316 873 8157 ; Tel: +43 316 873 8140
| | - Wolfgang E Ernst
- Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria . ; ; ; Tel: +43 316 873 8157 ; Tel: +43 316 873 8140
| | - Andreas W Hauser
- Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria . ; ; ; Tel: +43 316 873 8157 ; Tel: +43 316 873 8140
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3
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Topolski JE, Kafader JO, Marrero-Colon V, Iyengar SS, Hratchian HP, Jarrold CC. Exotic electronic structures of SmxCe3−xOy (x = 0-3; y = 2-4) clusters and the effect of high neutral density of low-lying states on photodetachment transition intensities. J Chem Phys 2018; 149:054305. [DOI: 10.1063/1.5043490] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Josey E. Topolski
- Department of Chemistry, Indiana University, 800 East Kirkwood Ave., Bloomington, Indiana 47405, USA
| | - Jared O. Kafader
- Department of Chemistry, Indiana University, 800 East Kirkwood Ave., Bloomington, Indiana 47405, USA
| | - Vicmarie Marrero-Colon
- Department of Chemistry, Indiana University, 800 East Kirkwood Ave., Bloomington, Indiana 47405, USA
| | - Srinivasan S. Iyengar
- Department of Chemistry, Indiana University, 800 East Kirkwood Ave., Bloomington, Indiana 47405, USA
| | - Hrant P. Hratchian
- Department of Chemistry and Chemical Biology, University of California, Merced, 5200 North Lake Road, Merced, California 95343, USA
| | - Caroline Chick Jarrold
- Department of Chemistry, Indiana University, 800 East Kirkwood Ave., Bloomington, Indiana 47405, USA
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4
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Hübner O, Himmel HJ. Metal Cluster Models for Heterogeneous Catalysis: A Matrix-Isolation Perspective. Chemistry 2018; 24:8941-8961. [PMID: 29457854 DOI: 10.1002/chem.201706097] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Indexed: 01/25/2023]
Abstract
Metal cluster models are of high relevance for establishing new mechanistic concepts for heterogeneous catalysis. The high reactivity and particular selectivity of metal clusters is caused by the wealth of low-lying electronically excited states that are often thermally populated. Thereby the metal clusters are flexible with regard to their electronic structure and can adjust their states to be appropriate for the reaction with a particular substrate. The matrix isolation technique is ideally suited for studying excited state reactivity. The low matrix temperatures (generally 4-40 K) of the noble gas matrix host guarantee that all clusters are in their electronic ground-state (with only a very few exceptions). Electronically excited states can then be selectively populated and their reactivity probed. Unfortunately, a systematic research in this direction has not been made up to date. The purpose of this review is to provide the grounds for a directed approach to understand cluster reactivity through matrix-isolation studies combined with quantum chemical calculations.
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Affiliation(s)
- Olaf Hübner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Hans-Jörg Himmel
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
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5
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Woodard MP, Akin ST, Dibble CJ, Duncan MA. Laser Synthesis and Spectroscopy of Ligand-Coated Chromium Oxide Nanoclusters. J Phys Chem A 2018. [DOI: 10.1021/acs.jpca.8b01219] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. P. Woodard
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - S. T. Akin
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - C. J. Dibble
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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6
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Affiliation(s)
- J. H. Marks
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - T. B. Ward
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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7
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Fernando A, Weerawardene KLDM, Karimova NV, Aikens CM. Quantum Mechanical Studies of Large Metal, Metal Oxide, and Metal Chalcogenide Nanoparticles and Clusters. Chem Rev 2015; 115:6112-216. [PMID: 25898274 DOI: 10.1021/cr500506r] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Amendra Fernando
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | | | - Natalia V Karimova
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | - Christine M Aikens
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
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8
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Adhikari D, Raghavachari K. Hydroxyl migration in heterotrimetallic clusters: an assessment of fluxionality pathways. J Phys Chem A 2014; 118:11047-55. [PMID: 25345598 DOI: 10.1021/jp5080835] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Water splitting at the unsaturated metal center and subsequent hydroxyl migration are key steps toward successful H2 liberation from cheap and abundant water using transition metal cluster anions. In this report we initiate a theoretical study (DFT) to assess the efficacy of heterometallic cores instead of the widely studied and well established homometallic cores. To accomplish this goal, one tungsten center in W3O6(-) core has been replaced by different transition metals such as titanium, technetium, and osmium. Introduction of the heterometal makes the core asymmetric and electronically anisotropic. To evaluate the efficiency of these heterometallic cores, fluxionality pathways for hydroxyl migration have been studied in detail. We show that the cores W2TcO6(-) (2) and W2OsO6(-) (3) can exhibit fluxionality for hydroxyl migration and thus can potentially facilitate H2 liberation from H2O. Notably, a new class of low-energy structures generated upon oxide bridge opening process and subsequent structural rearrangement facilitates the hydroxyl migration event. To illustrate the heterometallic effect further, we show that previously inaccessible energy barriers for hydroxyl migration in a homometallic trimolybdenum core become energetically achievable when one of the metals is replaced by a 5d element osmium.
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Affiliation(s)
- Debashis Adhikari
- Department of Chemistry and the Institute of Catalysis for Energy Processes, Northwestern University , Evanston, Illinois 60208, United States
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9
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Kim JB, Weichman ML, Neumark DM. Slow photoelectron velocity-map imaging spectroscopy of the Fe3O– and Co3O– anions. J Chem Phys 2014; 141:174307. [DOI: 10.1063/1.4900646] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jongjin B. Kim
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Marissa L. Weichman
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Daniel M. Neumark
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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10
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Tung NT, Tam NM, Nguyen MT, Lievens P, Janssens E. Influence of Cr doping on the stability and structure of small cobalt oxide clusters. J Chem Phys 2014; 141:044311. [DOI: 10.1063/1.4890500] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Wu L, Zhang C, Krasnokutski SA, Yang DS. Mass-analyzed threshold ionization and structural isomers of M3O4 (M = Sc, Y, and La). J Chem Phys 2012; 137:084312. [DOI: 10.1063/1.4747530] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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13
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Wu L, Liu Y, Zhang C, Li S, Dixon DA, Yang DS. Mass-analyzed threshold ionization of an excited state of lanthanum dioxide. J Chem Phys 2012; 137:034307. [DOI: 10.1063/1.4734312] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Dibble CJ, Akin ST, Ard S, Fowler CP, Duncan MA. Photodissociation of Cobalt and Nickel Oxide Cluster Cations. J Phys Chem A 2012; 116:5398-404. [DOI: 10.1021/jp302560p] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- C. J. Dibble
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556,
United States
| | - S. T. Akin
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556,
United States
| | - S. Ard
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556,
United States
| | - C. P. Fowler
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556,
United States
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556,
United States
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15
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Asmis KR. Structure characterization of metal oxide clusters by vibrational spectroscopy: possibilities and prospects. Phys Chem Chem Phys 2012; 14:9270-81. [PMID: 22569919 DOI: 10.1039/c2cp40762k] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
This article summarizes the methodological progress that has been made in the vibrational spectroscopy of isolated polynuclear metal oxide clusters, with particular emphasis on free electron laser-based infrared action spectroscopy of gas phase clusters, over the last decade. The possibilities, limitations and prospects of the various experimental approaches are discussed using representative examples from pivotal studies in the field.
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Affiliation(s)
- Knut R Asmis
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
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16
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17
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Hirabayashi S, Ichihashi M, Kondow T. Enhancement of Ammonia Dehydrogenation by Introduction of Oxygen onto Cobalt and Iron Cluster Cations. J Phys Chem A 2010; 114:13040-4. [DOI: 10.1021/jp109118d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Shinichi Hirabayashi
- East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan, and Cluster Research Laboratory, Toyota Technological Institute in East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan
| | - Masahiko Ichihashi
- East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan, and Cluster Research Laboratory, Toyota Technological Institute in East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan
| | - Tamotsu Kondow
- East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan, and Cluster Research Laboratory, Toyota Technological Institute in East Tokyo Laboratory, Genesis Research Institute, Inc., 717-86 Futamata, Ichikawa, Chiba 272-0001, Japan
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18
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Xie Y, Dong F, Heinbuch S, Rocca JJ, Bernstein ER. Oxidation reactions on neutral cobalt oxide clusters: experimental and theoretical studies. Phys Chem Chem Phys 2009; 12:947-59. [PMID: 20066380 DOI: 10.1039/b915590b] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Reactions of neutral cobalt oxide clusters (Co(m)O(n), m = 3-9, n = 3-13) with CO, NO, C(2)H(2), and C(2)H(4) in a fast flow reactor are investigated by time of flight mass spectrometry employing 118 nm (10.5 eV) single photon ionization. Strong cluster size dependent behavior is observed for all the oxidation reactions; the Co(3)O(4) cluster has the highest reactivity for reactions with CO and NO. Cluster reactivity is also highly correlated with either one or more following factors: cluster size, Co(iii) concentration, the number of the cobalt atoms with high oxidation states, and the presence of an oxygen molecular moiety (an O-O bond) in the Co(m)O(n) clusters. The experimental cluster observations are in good agreement with condensed phase Co(3)O(4) behavior. Density functional theory calculations at the BPW91/TZVP level are carried out to explore the geometric and electronic structures of the Co(3)O(4) cluster, reaction intermediates, transition states, as well as reaction mechanisms. CO, NO, C(2)H(2), and C(2)H(4) are predicted to be adsorbed on the Co(ii) site, and react with one of the parallel bridge oxygen atoms between two Co(iii) atoms in the Co(3)O(4) cluster. Oxidation reactions with CO, NO, and C(2)H(2) on the Co(3)O(4) cluster are estimated as thermodynamically favorable and overall barrierless processes at room temperature. The oxidation reaction with C(2)H(4) is predicted to have a very small overall barrier (<0.23 eV). The oxygen bridge between two Co(iii) sites in the Co(3)O(4) cluster is responsible for the oxidation reactions with CO, NO, C(2)H(2), and C(2)H(4). Based on the gas phase experimental and theoretical cluster studies, a catalytic cycle for these oxidation reactions on a condensed phase cobalt oxide catalyst is proposed.
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Affiliation(s)
- Yan Xie
- Department of Chemistry, NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, Fort Collins, CO 80523, USA
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19
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Gong Y, Zhou M, Andrews L. Spectroscopic and Theoretical Studies of Transition Metal Oxides and Dioxygen Complexes. Chem Rev 2009; 109:6765-808. [DOI: 10.1021/cr900185x] [Citation(s) in RCA: 324] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yu Gong
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
| | - Mingfei Zhou
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Advanced Materials Laboratory, Fudan University, Shanghai 200433, China
| | - Lester Andrews
- Department of Chemistry, University of Virginia, Charlottesville, Virginia 22901
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20
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Liu L, Zhao RN, Han JG, Liu FY, Pan GQ, Sheng LS. Does the Incoming Oxygen Atom Influence the Geometries and the Electronic and Magnetic Structures of Con Clusters? J Phys Chem A 2008; 113:360-6. [DOI: 10.1021/jp8080244] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Li Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China
| | - Run-Ning Zhao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China
| | - Ju-Guang Han
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China
| | - Fu-Yi Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China
| | - Guo-Qiang Pan
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China
| | - Liu-Si Sheng
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, People’s Republic of China
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21
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Johnson GE, Reveles JU, Reilly NM, Tyo EC, Khanna SN, Castleman AW. Influence of Stoichiometry and Charge State on the Structure and Reactivity of Cobalt Oxide Clusters with CO. J Phys Chem A 2008; 112:11330-40. [DOI: 10.1021/jp805186r] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Grant E. Johnson
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000
| | - J. Ulises Reveles
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000
| | - Nelly M. Reilly
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000
| | - Eric C. Tyo
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000
| | - Shiv N. Khanna
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000
| | - A. W. Castleman
- Departments of Chemistry and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284-2000
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22
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Reed ZD, Duncan MA. Photodissociation of Yttrium and Lanthanum Oxide Cluster Cations. J Phys Chem A 2008; 112:5354-62. [DOI: 10.1021/jp800588r] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Z. D. Reed
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
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23
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Molek KS, Anfuso-Cleary C, Duncan MA. Photodissociation of Iron Oxide Cluster Cations. J Phys Chem A 2008; 112:9238-47. [DOI: 10.1021/jp8009436] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- K. S. Molek
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - C. Anfuso-Cleary
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
| | - M. A. Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556
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Molek KS, Reed ZD, Ricks AM, Duncan MA. Photodissociation of Chromium Oxide Cluster Cations. J Phys Chem A 2007; 111:8080-9. [PMID: 17665887 DOI: 10.1021/jp073789+] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Chromium oxide cluster cations, Cr(n)O(m)+, are produced by laser vaporization in a pulsed nozzle cluster source and detected with time-of-flight mass spectrometry. The mass spectrum exhibits a limited number of stoichiometries for each value of n, where m > n. The cluster cations are mass selected and photodissociated using the second (532 nm) or third (355 nm) harmonic output of a Nd:YAG laser. At either wavelength, multiphoton absorption is required to dissociate these clusters, which is consistent with their expected strong bonding. Cluster dissociation occurs via elimination of molecular oxygen, or by fission processes producing stable cation species and/or eliminating stable neutrals such as CrO3, Cr(2)O(5), or Cr(4)O(10). Specific cation clusters identified to be stable because they are produced repeatedly in the decomposition of larger clusters include Cr(2)O(4)+, Cr(3)O(6)+, Cr(3)O(7)+, Cr(4)O(9)+, and Cr(4)O(10)+.
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Affiliation(s)
- K S Molek
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
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Wyrwas RB, Yoder BL, Maze JT, Jarrold CC. Reactivity of Small MoxOy- Clusters toward Methane and Ethane. J Phys Chem A 2006; 110:2157-64. [PMID: 16466251 DOI: 10.1021/jp057195n] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The reactions of Mo2Oy- suboxide clusters with both methane and ethane have been studied with a combination of mass spectrometry, anion photoelectron spectroscopy, and density functional theory calculations. Reactions were carried out under "gentle" and "violent" conditions. For methane, a number of products appeared under the gentler source conditions that were more logically attributed to dissociation of Mo2Oy- clusters upon reacting with methane to form MoCH2-, Mo(O)CH2-, and HMo(O2)CH3-. With ethane, products observed under the same gentle conditions were Mo(O)C2H2-, Mo(O)C2H4-, Mo(O2)C2H4-, and Mo(O2)(C2H5)2-. As expected, more products were observed when the reactions were carried out under violent conditions. The photoelectron spectra obtained for these species were compared to calculated adiabatic and vertical electron affinities and vibrational frequencies, leading to definitive structural assignments for several of the products.
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Affiliation(s)
- Richard B Wyrwas
- Indiana University, Department of Chemistry, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, USA
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Molek KS, Jaeger TD, Duncan MA. Photodissociation of vanadium, niobium, and tantalum oxide cluster cations. J Chem Phys 2005; 123:144313. [PMID: 16238397 DOI: 10.1063/1.2050650] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Transition-metal oxide clusters of the form M(n)O(m) (+)(M=V,Nb,Ta) are produced by laser vaporization in a pulsed nozzle cluster source and detected with time-of-flight mass spectrometry. Consistent with earlier work, cluster oxides for each value of n produce only a limited number of stoichiometries, where m>n. The cluster cations are mass selected and photodissociated using the second (532 nm) or third (355 nm) harmonic of a Nd:YAG (yttrium aluminum garnet) laser. All of these clusters require multiphoton conditions for dissociation, consistent with their expected strong bonding. Dissociation occurs by either elimination of oxygen or by fission, repeatedly producing clusters having the same specific stoichiometries. In oxygen elimination, vanadium species tend to lose units of O(2), whereas niobium and tantalum lose O atoms. For each metal increment n, oxygen elimination proceeds until a terminal stoichiometry is reached. Clusters having this stoichiometry do not eliminate more oxygen, but rather undergo fission, producing smaller M(n)O(m) (+) species. The smaller clusters produced as fission products represent the corresponding terminal stoichiometries for those smaller n values. The terminal stoichiometries identified are the same for V, Nb, and Ta oxide cluster cations. This behavior suggests that these clusters have stable bonding networks at their core, but additional excess oxygen at their periphery. These combined results determine that M(2)O(4) (+), M(3)O(7) (+), M(4)O(9) (+), M(5)O(12) (+), M(6)O(14) (+), and M(7)O(17) (+) have the greatest stability for V, Nb, and Ta oxide clusters.
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Affiliation(s)
- K S Molek
- Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556, USA
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Liu F, Li FX, Armentrout PB. Guided ion-beam studies of the reactions of Con+ (n=2–20) with O2: Cobalt cluster-oxide and -dioxide bond energies. J Chem Phys 2005; 123:64304. [PMID: 16122305 DOI: 10.1063/1.1998836] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The kinetic-energy dependence for the reactions of Co(n)+ (n=2-20) with O2 is measured as a function of kinetic energy over a range of 0 to 10 eV in a guided ion-beam tandem mass spectrometer. A variety of Co(m)+, Co(m)O+, and Co(m)O2+ (m < or = n) product ions is observed, with the dioxide cluster ions dominating the products for all larger clusters. Reaction efficiencies of Co(n)+ cations with O2 are near unity for all but the dimer. Bond dissociation energies for both cobalt cluster oxides and dioxides are derived from threshold analysis of the energy dependence of the endothermic reactions using several different methods. These values show little dependence on cluster size for clusters larger than three atoms. The trends in this thermochemistry and the stabilities of oxygenated cobalt clusters are discussed. The bond energies of Co(n)+-O for larger clusters are found to be very close to the value for desorption of atomic oxygen from bulk-phase cobalt. Rate constants for O2 chemisorption on the cationic clusters are compared with results from previous work on cationic, anionic, and neutral cobalt clusters.
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Affiliation(s)
- Fuyi Liu
- Department of Chemistry, University of Utah, Salt Lake City, Utah 84112, USA
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Yoder BL, Maze JT, Raghavachari K, Jarrold CC. Structures of Mo2Oy− and Mo2Oy (y=2, 3, and 4) studied by anion photoelectron spectroscopy and density functional theory calculations. J Chem Phys 2005; 122:094313. [PMID: 15836134 DOI: 10.1063/1.1853379] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The competitive structural isomers of the Mo(2)O(y) (-)Mo(2)O(y) (y=2, 3, and 4) clusters are investigated using a combination of anion photoelectron (PE) spectroscopy and density functional theory calculations. The PE spectrum and calculations for MoO(3) (-)MoO(3) are also presented to show the level of agreement to be expected between the spectra and calculations. For MoO(3) (-) and MoO(3), the calculations predict symmetric C(3v) structures, an adiabatic electron affinity of 3.34 eV, which is above the observed value 3.17(2) eV. However, there is good agreement between observed and calculated vibrational frequencies and band profiles. The PE spectra of Mo(2)O(2) (-) and Mo(2)O(3) (-) are broad and congested, with partially resolved vibrational structure on the lowest energy bands observed in the spectra. The electron affinities (EA(a)s) of the corresponding clusters are 2.24(2) and 2.33(7) eV, respectively. Based on the calculations, the most stable structure of Mo(2)O(2) (-) is Y shaped, with the two Mo atoms directly bonded. Assignment of the Mo(2)O(3) (-) spectrum is less definitive, but a O-Mo-O-Mo-O structure is more consistent with overall electronic structure observed in the spectrum. The PE spectrum of Mo(2)O(4) (-) shows cleanly resolved vibrational structure and electronic bands, and the EA of the corresponding Mo(2)O(4) is determined to be 2.13(4) eV. The structure most consistent with the observed spectrum has two oxygen bridge bonds between the Mo atoms.
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Affiliation(s)
- Bruce L Yoder
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405-7102, USA
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Matsuda Y, Bernstein ER. On the Titanium Oxide Neutral Cluster Distribution in the Gas Phase: Detection through 118 nm Single-Photon and 193 nm Multiphoton Ionization. J Phys Chem A 2004; 109:314-9. [PMID: 16833349 DOI: 10.1021/jp040670h] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Titanium oxide clusters are generated in a supersonic expansion by laser ablation of the metal and reaction with oxygen (0.1-6%) in He expansion gas. Mass spectra of the titanium oxide clusters are observed by photoionization with lasers of three different wavelengths: 118, 193, and 355 nm. Only the 118 nm (10.5 eV) light can ionize Ti(m)O(n) neutral clusters without fragmentation. Both the 193 nm (6.4 eV) and 355 nm (3.5 eV) multiphoton ionization cause fragmentation of the neutral clusters during the ionization process and, thus, can complicate the determination of the stable neutral Ti(m)O(n) gas-phase species. Employing 118 nm single-photon ionization and line-width data, the Ti(m)O(2m) and Ti(m)O(2m+1) series are found to be the most stable neutral cluster species for high oxygen content in the expansion gas. Fragmentation during the multiphoton ionization process for 193 nm light yields the cluster ions Ti(m)O(2m-1,-2)+. These ions are formed by the loss of one or two oxygen atoms from Ti(m)O(2m,2m+1) neutral species. The dominant cluster growth process is suggested to be through the addition of TiO2 species. For low oxygen content (<2%) in the expansion gas, oxygen-deficient clusters of the form Ti(m)O(2m-1,-2) are also observed. These latter series are not fragmented by the 193 nm ionization process.
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Affiliation(s)
- Yoshiyuki Matsuda
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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Matsuda Y, Shin DN, Bernstein ER. On the zirconium oxide neutral cluster distribution in the gas phase: Detection through 118 nm single photon, and 193 and 355 nm multiphoton, ionization. J Chem Phys 2004; 120:4142-9. [PMID: 15268580 DOI: 10.1063/1.1643731] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Zirconium oxide clusters are generated in the gas phase by laser ablation of the metal into a flow of ca. 5% O2/95% He at 100 psig and supersonic expansion into a vacuum chamber. Mass spectra of neutral gas phase zirconium oxide clusters are obtained through photoionization at three different laser wavelengths: 118, 193, and 355 nm. Ionization of the clusters with 118 nm laser radiation is through a single photon ionization mechanism, while ionization by 193 and 355 nm laser radiation is through a multiphoton (three or more photon) mechanism. Fragment ion features are observed in the mass spectra of ZrmOn+ for only the 193 nm and 355 nm ionization schemes. The true neutral ZrmOn cluster distribution is obtained only through 118 nm single photon ionization, as verified by mass spectral peak linewidths and calculations of the cluster binding energies, ionization energies, and fragmentation rates. The neutral cluster distribution consists mainly of the series ZrmO2m and ZrmO(2m+1) for m = 1,..., approximately 30.
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Affiliation(s)
- Y Matsuda
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA
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