1
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Armentrout PB, Lushchikova OV, Schuurman JL, Nooteboom S, Ghiassee M, Boles GC, Bakker JM. Infrared Spectroscopic Characterization of Early 4d Transition Metal Carbene Cations, ZrCH 2+ and NbCH 2. J Phys Chem A 2024; 128:6658-6667. [PMID: 39083656 DOI: 10.1021/acs.jpca.4c03553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2024]
Abstract
IR multiple-photon dissociation (IRMPD) action spectroscopy is combined with quantum chemical calculations to examine the [M,C,2H]+ species for the early 4d metals, M = Zr and Nb. These ions were formed by reacting laser ablated M+ ions with cyclopropane (c-C3H6) in a molecular beam apparatus. Both IRMPD spectra exhibit one major band near 700 cm-1 and a second weaker band at about twice that wavenumber, more evident when irradiated in focus. The [Nb,C,2H]+ species also has a sharp band at 800 cm-1. Comparison with B3LYP calculations allow assignment of the [M,C,2H]+ structures to agostic carbenes, which is similar to the structures found for the 5d analogues, WCH2+ and TaCH2+. A molecular orbital analysis traces the reasons for the agostic deformation from a classic C2v symmetric carbene.
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Affiliation(s)
- P B Armentrout
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Olga V Lushchikova
- Institute for Molecules and Materials, HFML-FELIX, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Jelle L Schuurman
- Institute for Molecules and Materials, HFML-FELIX, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Sjoerd Nooteboom
- Institute for Molecules and Materials, HFML-FELIX, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - Maryam Ghiassee
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Georgia C Boles
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, United States
| | - Joost M Bakker
- Institute for Molecules and Materials, HFML-FELIX, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
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2
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Wensink FJ, Smink CE, Stevenson BC, Steele RP, Bakker JM, Armentrout PB. IR spectroscopic characterization of [M,C,2H] + (M = Ru and Rh) products formed by reacting 4d transition metal cations with oxirane: Spectroscopic evidence for multireference character in RhCH 2. Phys Chem Chem Phys 2024; 26:11445-11458. [PMID: 38572552 PMCID: PMC11022548 DOI: 10.1039/d4cp00012a] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/13/2024] [Indexed: 04/05/2024]
Abstract
A combination of infrared multiple-photon dissociation (IRMPD) action spectroscopy and quantum chemical calculations was employed to investigate the [M,C,2H]+ (M = Ru and Rh) species. These ions were formed by reacting laser ablated M+ ions with oxirane (ethylene oxide, c-C2H4O) in a room-temperature ion trap. IRMPD spectra for the Ru species exhibit one major band and two side bands, whereas spectra for the Rh species contain more distinct bands. Comparison with density functional theory (DFT), coupled-cluster (CCSD), and equation-of-motion spin-flip CCSD (EOM-SF-CCSD) calculations allows assignment of the [M,C,2H]+ structures. For the spectrum of [Ru,C,2H]+, a combination of HRuCH+ and RuCH2+ structures reproduces the observed spectrum at all levels of theory. The well-resolved spectrum of [Rh,C,2H]+ could not be assigned unambiguously to any calculated structure using DFT approaches. The EOM-SF-CCSD calculations showed that the ground-state surface has multireference electronic character, and symmetric carbenes in both the 1A1 and 3A2 states are needed to reproduce the observed spectrum.
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Affiliation(s)
- Frank J Wensink
- Radboud University, Institute for Molecules and Materials, HFML-FELIX, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Corry E Smink
- Radboud University, Institute for Molecules and Materials, HFML-FELIX, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Brandon C Stevenson
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
| | - Ryan P Steele
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
| | - Joost M Bakker
- Radboud University, Institute for Molecules and Materials, HFML-FELIX, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - P B Armentrout
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
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3
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Wensink FJ, Smink CE, Armentrout PB, Bakker JM. IR spectroscopic characterization of 3d transition metal carbene cations, FeCH 2+ and CoCH 2+: periodic trends and a challenge for DFT approaches. Phys Chem Chem Phys 2024; 26:9948-9962. [PMID: 38497938 DOI: 10.1039/d4cp00026a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
A combination of IR multiple-photon dissociation (IRMPD) action spectroscopy and quantum chemical calculations was employed to investigate the [M,C,2H]+ (M = Fe and Co) species. These were formed by reacting laser ablated M+ ions with oxirane (ethylene oxide, c-C2H4O) in a room temperature ion trap. IRMPD spectra for the Fe and Co species are very similar and exhibit one major band. Comparison with density functional theory (DFT) and coupled cluster with single and double excitations (CCSD) calculations allows assignment of the spectra to MCH2+ carbene structures. For these 3d transition metal systems, experimental IRMPD spectra compare relatively poorly with DFT calculated IR spectra, but CCSD calculated spectra are a much better match primarily because the M-C stretch gains significant intensity. The origins of this behavior are explored in some detail. The present results are also compared to previous results for the 4d and 5d congeners and the periodic trends in these structures are evaluated.
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Affiliation(s)
- Frank J Wensink
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - Corry E Smink
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
| | - P B Armentrout
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112, USA.
| | - Joost M Bakker
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
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4
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Blagojevic V, Böhme DK. Relativistic Effects on Rate and Product Formation in the Gas‐Phase Methane Chemistry of Late Atomic Transition Metal Cations. Isr J Chem 2023. [DOI: 10.1002/ijch.202300015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Affiliation(s)
| | - Diethard K. Böhme
- Department of Chemistry York University Toronto Ontario Canada M3J 1P3
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5
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Dramatic Size‐dependence of Rh
n
+
Clusters in Reacting with Small Hydrocarbons: Rh
3
+
Cluster Catalysis for Dehydrogenation. ChemistrySelect 2022. [DOI: 10.1002/slct.202203632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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6
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Yan L, Li S, Zhou S. On the origin of reactivity variation upon sequential ligation: the [Re(Cl) x] +/CH 4 ( x = 1-3) couples. Phys Chem Chem Phys 2021; 23:24319-24327. [PMID: 34673861 DOI: 10.1039/d1cp03468e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The potential of [ReClx]+ (x = 1-3) in activating methane has been explored by using a combination of gas-phase experiments and high-level quantum calculations. When the number of Cl ligands increases, the reactivity towards methane activation varies accordingly. While [ReClx]+ (x = 1-2) are able to dehydrogenate methane by a three-state reactivity scenario, [ReCl3]+ shows inertness towards methane at ambient conditions. Furthermore, the product ion [ClRe(H)CH]+ of the [ReCl]+/CH4 couple could continue to activate methane and liberate molecular dihydrogen but another product ion [Cl2ReCH2]+ is unreactive with methane. Obviously, the nature and the number of ligands make a difference to the reactivity towards methane activation. The associated reaction mechanism and the electron origins for the rather different reactivities are discussed in detail. Finally and more importantly, instructive information concerning the rational design of Re-catalysts for methane conversion is obtained.
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Affiliation(s)
- Linghui Yan
- College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, 310027 Hangzhou, P. R. China. .,Institute of Zhejiang University - Quzhou, 78 Jiuhua Boulevard North, 324000 Quzhou, P. R. China
| | - Shihan Li
- College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, 310027 Hangzhou, P. R. China. .,Institute of Zhejiang University - Quzhou, 78 Jiuhua Boulevard North, 324000 Quzhou, P. R. China
| | - Shaodong Zhou
- College of Chemical and Biological Engineering, Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, Zhejiang University, 310027 Hangzhou, P. R. China. .,Institute of Zhejiang University - Quzhou, 78 Jiuhua Boulevard North, 324000 Quzhou, P. R. China
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7
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Lam CS, Lau KC. High-Level ab Initio Predictions for the Ionization Energies, Bond Dissociation Energies, and Heats of Formation of Vanadium Methylidene, Vanadium Methyl Species, and Their Cations (VCH 2/VCH 2+, VCH 3/VCH 3+). J Phys Chem A 2021; 125:4957-4966. [PMID: 34076442 DOI: 10.1021/acs.jpca.1c01381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The ionization energies of VCH2 and VCH3, the various 0 K bond dissociation energies (D0s) in their neutrals and cations, and their respective heats of formation at 0 and 298 K are computed by the single-reference, wave function-based CCSDTQ/CBS procedure. The core of the composite method is the approximation to the complete basis set (CBS) limit at the coupled cluster (CC) level which includes up to full quadruple excitations. The zero-point vibrational energy, core-valence correlation, spin-orbit coupling, and scalar relativistic effects have their contributions incorporated in an additive manner. For the species in the current study, this protocol requires geometry optimizations and harmonic frequency calculations practically no higher than the CCSD(T)/aug-cc-pwCVTZ and CCSD(T)/aug-cc-pVTZ levels, respectively. The present calculations successfully predict D0(V+-CH3) = 2.126 eV and D0(V+-CH2) = 3.298 eV in remarkable agreement with the data recently measured by a spin-orbit state selected V+ + CH4 collision experiment (Phys. Chem. Chem. Phys. 2021, 23, 273-286). The good accord encourages the use of CCSDTQ/CBS protocol in thermochemical predictions of various feasible product channels identified in methane activation by transition metal species.
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Affiliation(s)
- Chow-Shing Lam
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
| | - Kai-Chung Lau
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong
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8
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Armentrout PB, Stevenson BC, Yang F, Wensink FJ, Lushchikova OV, Bakker JM. Infrared Spectroscopy of Gold Carbene Cation (AuCH 2+): Covalent or Dative Bonding? J Phys Chem A 2019; 123:8932-8941. [PMID: 31542925 DOI: 10.1021/acs.jpca.9b08049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present work explores the structure of the gold carbene cation, AuCH2+, using infrared multiple photon dissociation action spectroscopy and density functional theory (DFT). Unlike several other 5d transition-metal cations (M+ = Ta+, W+, Os+, Ir+, and Pt+) that react with methane by dehydrogenation to form MCH2+ species, gold cations are unreactive with methane at thermal energies. Instead, the metal carbene is formed by reacting atomic gold cations formed in a laser ablation source with ethylene oxide (cC2H4O) pulsed into a reaction channel downstream. The resulting [Au,C,2H]+ product photofragmented by loss of H2 as induced by radiation provided by the free-electron laser for intracavity experiments in the 300-1800 cm-1 range. Comparison of the experimental spectrum, obtained by monitoring the appearance of AuC+, and DFT calculated spectra leads to the identification of the ground-state carbene, AuCH2+ (1A1), as the species formed, as previously postulated theoretically. Unlike the covalent double bonds formed by the lighter, open-shell 5d transition metals, the closed-shell Au+ (1S, 5d10) atom binds to methylene by donation of a pair of electrons from CH2(1A1) into the empty 6s orbital of gold coupled with π back-bonding, i.e., dative bonding, as explored computationally. Contributions to the AuC+ appearance spectrum from larger complexes are also considered, and H2CAu+(c-C2H4O) seems likely to contribute one band observed.
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Affiliation(s)
- P B Armentrout
- Department of Chemistry , University of Utah , 315 South 1400 East, Room 2020 , Salt Lake City , Utah 84112 , United States
| | - Brandon C Stevenson
- Department of Chemistry , University of Utah , 315 South 1400 East, Room 2020 , Salt Lake City , Utah 84112 , United States
| | - Fan Yang
- Department of Chemistry , University of Utah , 315 South 1400 East, Room 2020 , Salt Lake City , Utah 84112 , United States
| | - Frank J Wensink
- Institute for Molecules and Materials, FELIX Laboratory , Radboud University , Toernooiveld 7 , 6525 ED Nijmegen , The Netherlands
| | - Olga V Lushchikova
- Institute for Molecules and Materials, FELIX Laboratory , Radboud University , Toernooiveld 7 , 6525 ED Nijmegen , The Netherlands
| | - Joost M Bakker
- Institute for Molecules and Materials, FELIX Laboratory , Radboud University , Toernooiveld 7 , 6525 ED Nijmegen , The Netherlands
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9
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Armentrout PB, Kuijpers SEJ, Lushchikova OV, Hightower RL, Boles GC, Bakker JM. Spectroscopic Identification of the Carbyne Hydride Structure of the Dehydrogenation Product of Methane Activation by Osmium Cations. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:1781-1790. [PMID: 29633220 DOI: 10.1007/s13361-018-1929-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 02/15/2018] [Accepted: 02/23/2018] [Indexed: 06/08/2023]
Abstract
The present work explores the structures of species formed by dehydrogenation of methane (CH4) and perdeuterated methane (CD4) by the 5d transition metal cation osmium (Os+). Using infrared multiple photon dissociation (IRMPD) action spectroscopy and density functional theory (DFT), the structures of the [Os,C,2H]+ and [Os,C,2D]+ products are explored. This study complements previous work on the related species formed by dehydrogenation of methane by four other 5d transition metal cations (M+ = Ta+, W+, Ir+, and Pt+). Osmium cations are formed in a laser ablation source, react with methane pulsed into a reaction channel downstream, and the resulting products spectroscopically characterized through photofragmentation using the Free-Electron Laser for IntraCavity Experiments (FELICE) in the 300-1800 cm-1 range. Photofragmentation was monitored by the loss of H2/D2. Comparison of the experimental spectra and DFT calculated spectra leads to identification of the ground state carbyne hydride, HOsCH+ (2A') as the species formed, as previously postulated theoretically. Further, a full description of the systematic spectroscopic shifts observed for deuterium labeling of these complexes, some of the smallest systems to be studied using IRMPD action spectroscopy, is achieved. A full rotational contour analysis explains the observed linewidths as well as the observation of doublet structures in several bands, consistent with previous observations for HIrCH+ (2A'). Graphical Abstract ᅟ.
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Affiliation(s)
- P B Armentrout
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA.
| | - Stach E J Kuijpers
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
| | - Olga V Lushchikova
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
| | - Randy L Hightower
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
| | - Georgia C Boles
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT, 84112, USA
| | - Joost M Bakker
- Radboud University, Institute for Molecules and Materials, FELIX Laboratory, Toernooiveld 7c, 6525 ED, Nijmegen, The Netherlands
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10
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Gentleman AS, Green AE, Price DR, Cunningham EM, Iskra A, Mackenzie SR. Infrared Spectroscopy of Au +(CH 4) n Complexes and Vibrationally-Enhanced C-H Activation Reactions. Top Catal 2017; 61:81-91. [PMID: 31258301 PMCID: PMC6560929 DOI: 10.1007/s11244-017-0868-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A combined spectroscopic and computational study of gas-phase Au+(CH4)n (n = 3–8) complexes reveals a strongly-bound linear Au+(CH4)2 core structure to which up to four additional ligands bind in a secondary coordination shell. Infrared resonance-enhanced photodissociation spectroscopy in the region of the CH4a1 and t2 fundamental transitions reveals essentially free internal rotation of the core ligands about the H4C–Au+–CH4 axis, with sharp spectral features assigned by comparison with spectral simulations based on density functional theory. In separate experiments, vibrationally-enhanced dehydrogenation is observed when the t2 vibrational normal mode in methane is excited prior to complexation. Clear infrared-induced enhancement is observed in the mass spectrum for peaks corresponding 4u below the mass of the Au+(CH4)n=2,3 complexes corresponding, presumably, to the loss of two H2 molecules.
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Affiliation(s)
- Alexander S Gentleman
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | - Alice E Green
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | - Daniel R Price
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | - Ethan M Cunningham
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | - Andreas Iskra
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
| | - Stuart R Mackenzie
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ UK
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11
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Zimmermann P, Limberg C. Activation of Small Molecules at Nickel(I) Moieties. J Am Chem Soc 2017; 139:4233-4242. [DOI: 10.1021/jacs.6b12434] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Philipp Zimmermann
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Christian Limberg
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
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12
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Silva López C, Faza ON, Mansell A, Theis Z, Bellert D. Three Reaction Channels with Signature Proton Transfers in the Ni(I)-Catalyzed Decomposition of Ethyl Acetate. Organometallics 2017. [DOI: 10.1021/acs.organomet.6b00769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Carlos Silva López
- Universidade de Vigo, Departamento de Quı́mica
Orgánica, Campus Lagoas-Marcosende, 36310 Vigo, Spain
| | - Olalla Nieto Faza
- Universidade de Vigo, Departamento de Quı́mica
Orgánica, Campus Lagoas-Marcosende, 36310 Vigo, Spain
| | - Adam Mansell
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Zachry Theis
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
| | - Darrin Bellert
- Department
of Chemistry and Biochemistry, Baylor University, Waco, Texas 76798, United States
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13
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Mansell A, Theis Z, Gutierrez MG, Faza ON, Lopez CS, Bellert DJ. Submerged Barriers in the Ni(+) Assisted Decomposition of Propionaldehyde. J Phys Chem A 2016; 120:2275-84. [PMID: 27054589 DOI: 10.1021/acs.jpca.5b08444] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The reaction dynamics of the Ni(+) mediated decarbonylation of propionaldehyde was assessed using the single photon initiated decomposition rearrangement reaction (SPIDRR) technique. The exothermic production of Ni(+)CO was temporally monitored and the associated rate constants, k(E), were extracted as a function of activating photon energy. In addition, the reaction potential energy surface was calculated at the UCCSD(T)/def2-TZVP//PBEPBE/cc-pVDZ level of theory to provide an atomistic description of the reaction profile. The decarbonylation of propionaldehyde can be understood as proceeding through parallel competitive reaction pathways that are initiated by Ni(+) insertion into either the C-C or C-H bond of the propionaldehyde carbonyl carbon. Both paths lead to the elimination of neutral ethane and are governed by submerged barriers. The lower energy sequence is a consecutive C-C/C-H addition process with a submerged barrier of 14 350 ± 600 cm(-1). The higher energy sequence is a consecutive C-H/C-C addition process with a submerged barrier of 15 400 ± 600 cm(-1). Both barriers were determined using RRKM calculations fit to the experimentally determined k(E) values. The measured energy difference between the two barriers agrees with the DFT computed difference in rate limiting transition-state energies, 18 413 and 19 495 cm(-1).
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Affiliation(s)
- A Mansell
- Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76798, United States
| | - Z Theis
- Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76798, United States
| | - M G Gutierrez
- Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76798, United States
| | - O Nieto Faza
- Departamento de Quimica Organica, Universidad de Vigo , 36310, Vigo, Spain
| | - C Silva Lopez
- Departamento de Quimica Organica, Universidad de Vigo , 36310, Vigo, Spain
| | - D J Bellert
- Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76798, United States
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14
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Cox RM, Armentrout PB, de Jong WA. Activation of CH4 by Th+ as Studied by Guided Ion Beam Mass Spectrometry and Quantum Chemistry. Inorg Chem 2015; 54:3584-99. [DOI: 10.1021/acs.inorgchem.5b00137] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Richard M Cox
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - P. B. Armentrout
- Department
of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
| | - Wibe A. de Jong
- Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, United States
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15
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Zhao L, Ding Q, Xu W, Sang P, He X, Shi Z, Chi Y, Lu X, Guo W. The ligand effect on the selective C–H versus C–C bond activation of propane by NiBr+: a theoretical study. Theor Chem Acc 2015. [DOI: 10.1007/s00214-015-1628-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Schwarz H. How and Why Do Cluster Size, Charge State, and Ligands Affect the Course of Metal-Mediated Gas-Phase Activation of Methane? Isr J Chem 2014. [DOI: 10.1002/ijch.201300134] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Kocak A, Sallese Z, Johnston MD, Metz RB. Vibrational Spectroscopy of Co+(CH4)n and Ni+(CH4)n (n = 1–4). J Phys Chem A 2014; 118:3253-65. [DOI: 10.1021/jp500617n] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Abdulkadir Kocak
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Zachary Sallese
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Michael D. Johnston
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Ricardo B. Metz
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
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18
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Armentrout PB. Gas-phase perspective on the thermodynamics and kinetics of heterogeneous catalysis. Catal Sci Technol 2014. [DOI: 10.1039/c4cy00435c] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase studies of small transition metal cluster cations provide thermochemistry of utility to surface science and heterogeneous catalysis.
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19
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Armentrout PB, Parke L, Hinton C, Citir M. Activation of Methane by Os+: Guided-Ion-Beam and Theoretical Studies. Chempluschem 2013; 78:1157-1173. [DOI: 10.1002/cplu.201300147] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Indexed: 11/05/2022]
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20
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Roffe GW, Cox H. Computational Study of the Coordination of Methane to First Row Transition Metal Dication Complexes. J Phys Chem A 2013; 117:3017-24. [DOI: 10.1021/jp309739s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gavin W. Roffe
- Department of Chemistry, School
of Life Sciences, University of Sussex,
Brighton BN1 9QJ, U.K
| | - Hazel Cox
- Department of Chemistry, School
of Life Sciences, University of Sussex,
Brighton BN1 9QJ, U.K
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Kretschmer R, Schlangen M, Schwarz H. C–N coupling in the gas-phase reactions of ammonia and [M(CH)]+ (M = Ni, Pd, Pt): a combined experimental/computational exercise. Dalton Trans 2013; 42:4153-62. [DOI: 10.1039/c3dt32596b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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22
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Villarroel OJ, Laboren IE, Bellert DJ. Co(+)-assisted decomposition of h6-acetone and d6-acetone: acquisition of reaction rate constants and dynamics of the dissociative mechanism. J Phys Chem A 2012; 116:3081-8. [PMID: 22352987 DOI: 10.1021/jp2047135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Reaction rate constants have been acquired for the gaseous unimolecular decomposition reaction of the Co(+)(OC(CH(3))(2)) cluster ion and its deuterium labeled analog. Each rate constant is measured at a well resolved cluster internal energy within the range 12,300-16,100 cm(-1). The weighted, averaged kinetic isotope effect (KIE), k(H)/k(D) = 1.54 ± 0.05, is about three times smaller than the KIE measured for the rate-determining rate constants in the similar Ni(+)(OC(CH(3))(2)) decomposition reaction. These reactions likely follow the same oxidative addition-reductive elimination mechanism. Thus, this unexpected change in the KIE magnitudes is not due to differences in the dissociative reaction coordinates. Rather, we propose that the unique dissociation dynamics of these two similar systems is due to differences in the low-lying electronic structure of each transition metal ion.
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Affiliation(s)
- Otsmar J Villarroel
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place No. 97348, Waco, Texas 76798-7348, USA
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Schlangen M, Schwarz H. Probing elementary steps of nickel-mediated bond activation in gas-phase reactions: Ligand- and cluster-size effects. J Catal 2011. [DOI: 10.1016/j.jcat.2011.03.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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Liu S, Geng Z, Wang Y, Yan Y. DFT studies for dehydrogenation of methane by gas-phase Ru+. COMPUT THEOR CHEM 2011. [DOI: 10.1016/j.comptc.2011.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Laboren IE, Villarroel OJ, Dee SJ, Castleberry VA, Klausmeyer K, Bellert DJ. Reaction rate constants and mechanistic detail of the Ni+ + butanone reaction. J Phys Chem A 2011; 115:1810-20. [PMID: 21338169 DOI: 10.1021/jp111487r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The unimolecular decomposition kinetics of the jet-cooled Ni(+)-butanone cluster ion has been monitored over a range of internal energies (16000-18800 cm⁻¹). First-order rate constants are acquired for the precursor ion dissociation into three product channels. The temporal growth of each fragment ion is selectively monitored in a custom instrument and yields similar valued rate constants at a common ion internal energy. The decomposition reaction is proposed to proceed along two parallel reaction coordinates. Each dissociative pathway is rate-limited by the initial Ni(+) oxidative addition into either the C-CH₃ or C-C₂H₅ σ-bond in the butanone molecule. Ratios of integrated product ion intensities as well as the measured rate constants are used to determine values for each σ-bond activation rate constant. The lowest energy measurement presented in this study occurs when the binary complex ion possesses an internal energy of 16000 cm⁻¹. Under this condition, the Ni(+) assisted decomposition of the butanone molecule is rate limited by k(act)(C-C₂H₅) = (0.92 ± 0.08) × 10⁵ s⁻¹ and k(act)(C-CH₃) = (0.37 ± 0.03) × 10⁵ s⁻¹. The relative magnitudes of the two rate constants reflect the greater probability for reaction to occur along the C-C₂H₅ σ-bond insertion pathway, consistent with thermodynamic arguments. DFT calculations at the B3LYP/6-311++G(d,p) level of theory suggest the most likely geometries and relative energies of the reactants, intermediates, and products.
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Affiliation(s)
- Ivanna E Laboren
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798-7348, USA
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Zhang X, Schwarz H. Bonding in cationic MOH n + (M = K − La, Hf − Rn; n = 0–2): DFT performances and periodic trends. Theor Chem Acc 2010. [DOI: 10.1007/s00214-010-0861-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhang X, Schwarz H. Bonding in Cationic MCH2+(M=K-La, Hf-Rn): A Theoretical Study on Periodic Trends. Chemistry 2010; 16:5882-8. [DOI: 10.1002/chem.201000567] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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28
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Roithová J, Schröder D. Selective activation of alkanes by gas-phase metal ions. Chem Rev 2010; 110:1170-211. [PMID: 20041696 DOI: 10.1021/cr900183p] [Citation(s) in RCA: 377] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jana Roithová
- Department of Organic Chemistry, Charles University in Prague, Faculty of Sciences, Hlavova 8, 12843 Prague 2, Czech Republic.
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Dee SJ, Castleberry VA, Villarroel OJ, Laboren IE, Bellert DJ. Low-energy reaction rate constants for the Ni+-assisted decomposition of acetaldehyde: observation of C-H and C-C activation. J Phys Chem A 2010; 114:1783-9. [PMID: 20050634 DOI: 10.1021/jp910396t] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rate constants for the low-energy Ni(+)-assisted dissociative reaction of acetaldehyde have been measured under jet-cooled conditions in the gas phase. The rate constants are acquired through monitoring the time dependence of fragment Ni(+)CO formation. The decomposition of the precursor Ni(+)-acetaldehyde cluster ion proceeds via consecutive, parallel reaction coordinates that originate with the Ni(+)-assisted cleavage of either a C-C or an aldehyde C-H bond. The energies used to initiate these reactions are well below that required to cleave sigma-bonds in the isolated acetaldehyde molecule. Direct measurement of the reaction kinetics over a range of energies indicates that the rate-limiting step in the dissociative mechanism changes at cluster ion internal energies = 17,200 +/- 400 cm(-1). Arguments are presented that this energy marks the closure of the dissociative coordinate that initiates with C-H sigma-bond activation and thus provides a measure of the activation energy of this dissociative pathway.
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Affiliation(s)
- S Jason Dee
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place 97348, Waco, Texas 76798-7348, USA
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30
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Dee SJ, Castleberry VA, Villarroel OJ, Laboren IE, Frey SE, Ashley D, Bellert DJ. Rate-limiting step in the low-energy unimolecular decomposition reaction of Ni+* acetone into Ni+CO + ethane. J Phys Chem A 2009; 113:14074-80. [PMID: 19877648 DOI: 10.1021/jp906912d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rate constants for the low-energy Ni(+)-assisted C-C bond cleavage reaction of deuterium-labeled acetone have been acquired under jet-cooled conditions in the gas phase. The energies used to initiate the dissociative reactions of the precursor complex ion Ni(+)(d(6)-Ac) are well below that required to cleave C-C sigma-bonds in isolated organic molecules. The rate constants are compared to those acquired previously for the lighter Ni(+)(h(6)-Ac) isotope and result in a substantial kinetic isotope effect (k(H)/k(D) approximately 5.5). Arguments are made that implicate isomerization leading to C-C bond coupling as the rate-limiting step (not C-C sigma-bond activation) in the dissociative reaction.
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Affiliation(s)
- S Jason Dee
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798-7348, USA
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Castleberry VA, Dee SJ, Villarroel OJ, Laboren IE, Frey SE, Bellert DJ. The low-energy unimolecular reaction rate constants for the gas phase, Ni+-mediated dissociation of the C-C sigma bond in acetone. J Phys Chem A 2009; 113:10417-24. [PMID: 19725574 DOI: 10.1021/jp904561y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The time dependence of the gaseous unimolecular decomposition of the jet-cooled adduct ion, Ni+-OC(CH3)2, was monitored through selective detection of the Ni+CO fragment ion. Various resolved amounts of energy in the range 15600-18800 cm(-1) were supplied to initiate the dissociation reaction through absorption of laser photons by the title molecular complex. First-order rate constants, k(E), ranged from 113000 to 55000 s(-1) and decreased with decreasing amounts of internal excitation. The energy used to initiate the reaction is well below that required to fragment C-C sigma bonds and indicates the necessity of the Ni+ cation to induce bond activation and fragmentation. These measurements are carried out in a unique apparatus and represent the first direct kinetic study of such catalytic type reactions.
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Affiliation(s)
- Vanessa A Castleberry
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798-7348, USA
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Di Santo E, Michelini MC, Russo N. Activation of Ethane C−H and C−C Bonds by Gas Phase Th+ and U+: A Theoretical Study. J Phys Chem A 2009; 113:14699-705. [DOI: 10.1021/jp9048154] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E. Di Santo
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d’Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
| | - M. C. Michelini
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d’Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
| | - N. Russo
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d’Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
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Shayesteh A, Lavrov VV, Koyanagi GK, Bohme DK. Reactions of atomic cations with methane: gas phase room-temperature kinetics and periodicities in reactivity. J Phys Chem A 2009; 113:5602-11. [PMID: 19371125 DOI: 10.1021/jp900671c] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Reactions of methane have been measured with 59 atomic metal cations at room temperature in helium bath gas at 0.35 Torr using an inductively-coupled plasma/selected-ion flow tube (ICP/SIFT) tandem mass spectrometer. The atomic cations were produced at approximately 5500 K in an ICP source and allowed to decay radiatively and to thermalize by collisions with argon and helium atoms prior to reaction. Rate coefficients and product distributions are reported for the reactions of fourth-row atomic cations from K(+) to Se(+), of fifth-row atomic cations from Rb(+) to Te(+) (excluding Tc(+)), of sixth-row atomic cations from Cs(+) to Bi(+), and of the lanthanide cations from La(+) to Lu(+) (excluding Pm(+)). Two primary reaction channels were observed: C-H bond insertion with elimination of H(2), and CH(4) addition. The bimolecular H(2) elimination was observed in the reactions of CH(4) with As(+), Nb(+), and some sixth-row metal cations, i.e., Ta(+), W(+), Os(+), Ir(+), Pt(+); secondary and higher-order H(2) elimination was observed exclusively for Ta(+), W(+), and Ir(+) ions. All other transition-metal cations except Mn(+) and Re(+) were observed to react with CH(4) exclusively by addition, and up to two methane molecules were observed to add sequentially to most transition-metal ions. CH(4) addition was also observed for Ge(+), Se(+), La(+), Ce(+), and Gd(+) ions, while the other main-group and lanthanide cations did not react measurably with methane.
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Affiliation(s)
- Alireza Shayesteh
- Department of Chemistry, Centre for Research in Mass Spectrometry, York University, Toronto, Ontario, M3J 1P3, Canada
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Di Santo E, Michelini MDC, Russo N. Methane C−H Bond Activation by Gas-Phase Th+ and U+: Reaction Mechanisms and Bonding Analysis. Organometallics 2009. [DOI: 10.1021/om900156f] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Emanuela Di Santo
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d’Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
| | - Maria del Carmen Michelini
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d’Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
| | - Nino Russo
- Dipartimento di Chimica and Centro di Calcolo ad Alte Prestazioni per Elaborazioni Parallele e Distribuite-Centro d’Eccellenza MURST, Università della Calabria, I-87030 Arcavacata di Rende, Italy
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Schlangen M, Schwarz H. Ligand Effects on the Mechanisms of Thermal Bond Activation in the Gas-Phase Reactions NiX+/CH4→Ni(CH3)+/HX (X=H, CH3, OH, F). Short Communication. Helv Chim Acta 2008. [DOI: 10.1002/hlca.200890238] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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36
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Schröder D, Schwarz H. Gas-phase activation of methane by ligated transition-metal cations. Proc Natl Acad Sci U S A 2008; 105:18114-9. [PMID: 18955709 PMCID: PMC2587635 DOI: 10.1073/pnas.0801849105] [Citation(s) in RCA: 203] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Indexed: 11/18/2022] Open
Abstract
Motivated by the search for ways of a more efficient usage of the large, unexploited resources of methane, recent progress in the gas-phase activation of methane by ligated transition-metal ions is discussed. Mass spectrometric experiments demonstrate that the ligands can crucially influence both reactivity and selectivity of transition-metal cations in bond-activation processes, and the most reactive species derive from combinations of transition metals with the electronegative elements fluorine, oxygen, and chlorine. Furthermore, the collected knowledge about intramolecular kinetic isotope effects associated with the activation of C-H(D) bonds of methane can be used to distinguish the nature of the bond activation as a mere hydrogen-abstraction, a metal-assisted mechanism or more complex reactions such as formation of insertion intermediates or sigma-bond metathesis.
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Affiliation(s)
- Detlef Schröder
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague, Czech Republic; and
| | - Helmut Schwarz
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610 Prague, Czech Republic; and
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Schlangen M, Schröder D, Schwarz H. Ligand and Substrate Effects in Gas-Phase Reactions of NiX+/RH Couples (X=F, Cl, Br, I; R=CH3, C2H5,nC3H7,nC4H9). Chemistry 2007; 13:6810-6. [PMID: 17591727 DOI: 10.1002/chem.200700506] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The reactions of small saturated hydrocarbons by gaseous nickel cations NiX+ (X=F, Cl, Br, I) are investigated by means of electrospray ionization mass spectrometry. The halide cations are obtained from solutions of the corresponding Ni(II) salts in water or methanol as solvents. NiF+ is the only Ni(II) halide complex that brings about thermal activation of methane. The branching ratios of the observed reactions with C2H6, C3H8, and nC4H10 are shifted systematically by changing the nature of both the ligand X and the substrate RH. In the elimination of HX (X=F, Cl, Br, I), the formal oxidation state of the metal ion appears to be conserved, and the importance of this reaction channel decreases in going from NiF+ to NiI+. A reversed trend is observed in the losses of small closed-shell neutral molecules, that is, H2, CH4 and C2H6, which dominate the gas-phase ion chemistry of NiI+/RH couples. Additionally, inner-sphere electron-transfer reactions take place for a few systems, that is, the delivery of hydride or methanide ions from the hydrocarbon to NiX+ in the course of which the hydrocarbon is converted to a carbenium ion and the cationic metal complex gives rise to a neutral RNiX molecule (R=H, CH3). This process gains importance with decreasing atomic number of the halides and with increasing the size of the alkane. Thus, it constitutes the major pathway in the reactions of NiF+ with propane and n-butane, whereas it is not observed for any of the NiI+/RH couples investigated. Concerning the regioselectivity of the reactions with propane and n-butane, heterolytic cleavage of secondary carbon--hydrogen bonds is clearly preferred compared to that of primary ones, as revealed by deuterium labeling studies. For the NiF+/C3H8 couple, the selectivity of the hydride transfer is as large as 360 in favor of the secondary positions. Though smaller, large preferences for the activation of secondary C--H bonds are also operative in homolytic bond activation of RH (R=nC3H7, nC4H9).
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Affiliation(s)
- Maria Schlangen
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
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Schlangen M, Schröder D, Schwarz H. Pronounced ligand effects and the role of formal oxidation states in the nickel-mediated thermal activation of methane. Angew Chem Int Ed Engl 2007; 46:1641-4. [PMID: 17262870 DOI: 10.1002/anie.200603266] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Maria Schlangen
- Institut für Chemie der Technischen Universität Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
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Schlangen M, Schwarz H, Schröder D. Specific Processes and Scrambling in the Dehydrogenation of Ethane and the Degenerate Hydrogen Exchange in the Gas-Phase Ion Chemistry of the Ni(C,H3,O)+/C2H6 Couple. Helv Chim Acta 2007. [DOI: 10.1002/hlca.200790088] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Schlangen M, Schröder D, Schwarz H. Thermische Aktivierung von Methan durch kationische Nickelkomplexe: Einfluss von Liganden und formaler Oxidationsstufe. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200603266] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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