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Marcum JC, Metz RB. Vibrational Spectroscopy and Structural Analysis of V +(C 2H 6) n Clusters ( n = 1-4). J Phys Chem A 2023. [PMID: 37307201 DOI: 10.1021/acs.jpca.3c00301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The vibrational structure and binding motifs of vanadium cation-ethane clusters, V+(C2H6)n, for n = 1-4 are probed using infrared photodissociation spectroscopy in the C-H stretching region (2550-3100 cm-1). Comparison of spectra to scaled harmonic frequency spectra obtained using density functional theory suggests that ethane exhibits two primary binding motifs when interacting with the vanadium cation: an end-on η2 configuration and a side-on configuration. Determining the denticity of the side on isomer is complicated by the rotational motion of ethane, implying that structural analysis based solely on Born-Oppenheimer potential energy surface minimizations is insufficient and that a more sophisticated vibrationally adiabatic approach is necessary to interpret spectra. The lower-energy side-on configuration predominates in smaller clusters, but the end-on configuration becomes important for larger clusters as it helps to maintain a roughly square-planar geometry about the central vanadium. Proximate C-H bonds exhibit elongation and large red-shifts when compared to bare ethane, particularly in the case of the side-on isomer, demonstrating initial effects of C-H bond activation, which are underestimated by scaled harmonic frequency calculations. Tagging several of the clusters with argon and nitrogen results in nontrivial effects. The high binding energy of N2 can lead to the displacement of ethane from a side-on configuration into an end-on configuration. The presence of either one or two Ar or N2 can impact the overall symmetry of the cluster, which can alter the potential energy surface for ethane rotation in the side-on isomer and may affect the accessibility of low-lying electronic excited states of V+.
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Affiliation(s)
- Jesse C Marcum
- Department of Chemistry, Keene State College, Keene, New Hampshire 03435, United States
| | - Ricardo B Metz
- Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts 01003, United States
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Duncan MA. Invited review article: laser vaporization cluster sources. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2012; 83:041101. [PMID: 22559508 DOI: 10.1063/1.3697599] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The laser vaporization cluster source has been used for the production of gas phase atomic clusters and metal-molecular complexes for 30 years. Numerous experiments in the chemistry and physics of clusters have employed this source. Its operation is simple in principle, but there are many subtle design features that influence the number and size of clusters produced, as well as their composition, charge state, and temperature. This article examines all aspects of the design of these cluster sources, discussing the relevant chemistry, physics, and mechanical aspects of experimental configurations employed by different labs. The principles detailed here provide a framework for the design and implementation of this source for new applications.
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Affiliation(s)
- Michael A Duncan
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA.
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Mosley JD, Cheng TC, Hasbrouck SD, Ricks AM, Duncan MA. Electronic spectroscopy of CoNe+ via mass-selected photodissociation. J Chem Phys 2011; 135:104309. [DOI: 10.1063/1.3633472] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Walker NR, Walters RS, Duncan MA. Infrared photodissociation spectroscopy of V+(CO2)n and V+(CO2)nAr complexes. J Chem Phys 2006; 120:10037-45. [PMID: 15268025 DOI: 10.1063/1.1730217] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
V+(CO2)n and V+(CO2)nAr complexes are generated by laser vaporization in a pulsed supersonic expansion. The complexes are mass-selected within a reflectron time-of-flight mass spectrometer and studied by infrared resonance-enhanced (IR-REPD) photodissociation spectroscopy. Photofragmentation proceeds exclusively through loss of intact CO2 molecules from V+(CO2)n complexes or by elimination of Ar from V+(CO2)nAr mixed complexes. Vibrational resonances are identified and assigned in the region of the asymmetric stretch of free CO2 at 2349 cm(-1). A linear geometry is confirmed for V+(CO2). Small complexes have resonances that are blueshifted from the asymmetric stretch of free CO2, consistent with structures in which all ligands are bound directly to the metal ion. Fragmentation of the larger clusters terminates at the size of n=4, and a new vibrational band at 2350 cm(-1) assigned to external ligands is observed for V+(CO2)5 and larger cluster sizes. These combined observations indicate that the coordination number for CO2 molecules around V+ is exactly four. Fourfold coordination contrasts with that seen in condensed phase complexes, where a coordination number of six is typical for V+. The spectra of larger complexes provide evidence for an intracluster insertion reaction that produces a metal oxide-carbonyl species.
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Affiliation(s)
- N R Walker
- Department of Chemistry, University of Georgia, Athens, GA 30602-2556, USA
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Citir M, Altinay G, Metz RB. Electronic and Vibrational Spectroscopy and Vibrationally Mediated Photodissociation of V+(OCO). J Phys Chem A 2006; 110:5051-7. [PMID: 16610824 DOI: 10.1021/jp060375s] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Electronic spectra of gas-phase V+(OCO) are measured in the near-infrared from 6050 to 7420 cm(-1) and in the visible from 15,500 to 16,560 cm(-1), using photofragment spectroscopy. The near-IR band is complex, with a 107 cm(-1) progression in the metal-ligand stretch. The visible band shows clearly resolved vibrational progressions in the metal-ligand stretch and rock, and in the OCO bend, as observed by Brucat and co-workers. A vibrational hot band gives the metal-ligand stretch frequency in the ground electronic state nu3'' = 210 cm(-1). The OCO antisymmetric stretch frequency in the ground electronic state (nu1'') is measured by using vibrationally mediated photodissociation. An IR laser vibrationally excites ions to nu1'' = 1. Vibrationally excited ions selectively dissociate following absorption of a second, visible photon at the nu1' = 1 <-- nu1'' = 1 transition. Rotational structure in the resulting vibrational action spectrum confirms that V+(OCO) is linear and gives nu1'' = 2392.0 cm(-1). The OCO antisymmetric stretch frequency in the excited electronic state is nu1' = 2368 cm(-1). Both show a blue shift from the value in free CO2, due to interaction with the metal. Larger blue shifts observed for complexes with fewer ligands agree with trends seen for larger V+(OCO)n clusters.
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Affiliation(s)
- Murat Citir
- Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003, USA
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Walker NR, Walters RS, Grieves GA, Duncan MA. Growth dynamics and intracluster reactions in Ni+(CO2)n complexes via infrared spectroscopy. J Chem Phys 2004; 121:10498-507. [PMID: 15549932 DOI: 10.1063/1.1806821] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Ni(+)(CO(2))(n), Ni(+)(CO(2))(n)Ar, Ni(+)(CO(2))(n)Ne, and Ni(+)(O(2))(CO(2))(n) complexes are generated by laser vaporization in a pulsed supersonic expansion. The complexes are mass-selected in a reflectron time-of-flight mass spectrometer and studied by infrared resonance-enhanced photodissociation (IR-REPD) spectroscopy. Photofragmentation proceeds exclusively through the loss of intact CO(2) molecules from Ni(+)(CO(2))(n) and Ni(+)(O(2))(CO(2))(n) complexes, and by elimination of the noble gas atom from Ni(+)(CO(2))(n)Ar and Ni(+)(CO(2))(n)Ne. Vibrational resonances are identified and assigned in the region of the asymmetric stretch of CO(2). Small complexes have resonances that are blueshifted from the asymmetric stretch of free CO(2), consistent with structures having linear Ni(+)-O=C=O configurations. Fragmentation of larger Ni(+)(CO(2))(n) clusters terminates at the size of n=4, and new vibrational bands assigned to external ligands are observed for n> or =5. These combined observations indicate that the coordination number for CO(2) molecules around Ni(+) is exactly four. Trends in the loss channels and spectra of Ni(+)(O(2))(CO(2))(n) clusters suggest that each oxygen atom occupies a different coordination site around a four-coordinate metal ion in these complexes. The spectra of larger Ni(+)(CO(2))(n) clusters provide evidence for an intracluster insertion reaction assisted by solvation, producing a metal oxide-carbonyl species as the reaction product.
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Affiliation(s)
- N R Walker
- Department of Chemistry, University of Georgia, Athens, GA 30602-2556, USA
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Bellert D, Breckenridge WH. Bonding in ground-state and excited-state A+.Rg van der Waals ions (A = atom, Rg = rare-gas atom): a model-potential analysis. Chem Rev 2002; 102:1595-622. [PMID: 11996545 DOI: 10.1021/cr980090e] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- D Bellert
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, UT 84112, USA
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Burns KL, Bellert D, Leung AWK, Breckenridge WH. M+/Rg bonding: The effects of M+ permanent quadrupole moments (M+= atomic metal ion; Rg=rare gas atom). J Chem Phys 2001. [DOI: 10.1063/1.1361250] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Burns KL, Bellert D, Leung AWK, Breckenridge WH. The effects of dispersive Cn/Rn-attraction on M+/Rg bonding (M+=atomic metal ion, Rg=rare gas atom). J Chem Phys 2001. [DOI: 10.1063/1.1328748] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Van Hooydonk G. A Universal Two-Parameter Kratzer-Potential and Its Superiority over Morse's for Calculating and Scaling First-Order Spectroscopic Constants of 300 Diatomic Bonds. Eur J Inorg Chem 1999. [DOI: 10.1002/(sici)1099-0682(199910)1999:10<1617::aid-ejic1617>3.0.co;2-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Linton C, Simard B, Loock HP, Wallin S, Rothschopf GK, Gunion RF, Morse MD, Armentrout PB. Rydberg and pulsed field ionization-zero electron kinetic energy spectra of YO. J Chem Phys 1999. [DOI: 10.1063/1.479759] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Leung AWK, Bellert D, Julian RR, Breckenridge WH. Resonant two-color photoionization threshold measurements of the Zn+(4s)⋅Ar bond strength: Model-potential analysis of M+(ns)⋅Ar interactions. J Chem Phys 1999. [DOI: 10.1063/1.478534] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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