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Martínez-Fernández L, Ranković ML, Canon F, Nahon L, Giuliani A, Milosavljević AR, Martin-Somer A. Photodissociation of leucine-enkephalin protonated peptide: an experimental and theoretical perspective. RSC Adv 2024; 14:16809-16820. [PMID: 38784408 PMCID: PMC11112675 DOI: 10.1039/d4ra01690d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
Understanding the competing processes that govern far ultraviolet photodissociation (FUV-PD) of biopolymers such as proteins is a challenge. Here, we report a combined experimental and theoretical investigation of FUV-PD of protonated leucine-enkephalin pentapeptide ([YGGFL + H]+) in the gas-phase. Time-dependent density functional theory (TD-DFT) calculations in combination with experiments and previous results for amino acids and shorter peptides help in rationalizing the evolution of the excited states. The results confirm that fragmentation of [YGGFL + H]+ results mainly from vibrationally excited species in the ground electronic state, populated after internal conversion. We also propose fragmentation mechanisms for specific photo-fragments such as tyrosine side chain loss (with an extra hydrogen) or hydrogen loss. In general, we observe the same mechanisms as for smaller peptides or protonated Tyr and Phe, that are not quenched by the presence of other amino acids. Nevertheless, we also found some differences, as for H loss, in part due to the fact that the charge is solvated by the peptide chain and not only by the COOH terminal group.
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Affiliation(s)
- Lara Martínez-Fernández
- Departamento de Química Física de Materiales, Instituto de Química Física de Materiales, Instituto de Química Física Blas Cabrera, CSIC 28006 Madrid Spain
| | - Miloš Lj Ranković
- Institute of Physics Belgrade, University of Belgrade Pregrevica 118 11080 Belgrade Serbia
| | - Francis Canon
- SOLEIL l'Orme des Merisiers, St Aubin, BP48, F-91192 Gif sur Yvette Cedex France
| | - Laurent Nahon
- SOLEIL l'Orme des Merisiers, St Aubin, BP48, F-91192 Gif sur Yvette Cedex France
| | - Alexandre Giuliani
- SOLEIL l'Orme des Merisiers, St Aubin, BP48, F-91192 Gif sur Yvette Cedex France
- INRAE, Dpet. Transform UAR1008, Rue de la Géraudière, BP 71627 F-44316 Nantes France
| | | | - Ana Martin-Somer
- Departamento de Química Física Aplicada, Universidad Autónoma de Madrid Módulo 14 28049 Spain
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2
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Foley CD, Lee C, Abou Taka A, Au K, Chollet E, Kubasik MA, McCaslin LM, Zwier TS. Site-Specific Photochemistry along a Protonated Peptide Scaffold. J Am Chem Soc 2024; 146:13282-13295. [PMID: 38687970 DOI: 10.1021/jacs.4c01576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
We present a detailed study of the time-dependent photophysics and photochemistry of a known conformation of the two protonated pentapeptides Leu-enkephalin (Tyrosine-Glycine-Glycine-Phenylalanine-Leucine, YGGFL) and its chromophore-swapped analogue FGGYL, carried out under cryo-cooled conditions in the gas phase. Using ultraviolet-infrared (UV-IR) double resonance, we record excited state IR spectra as a function of time delay between UV and IR pulses. We identify unique Tyr OH stretch transitions due to the S1 state and the vibrationally excited triplet state(s) formed by intersystem crossing, Tn(v). Photofragment mass spectra are recorded out of the S1 origin and following UV-IR double resonance. Several competing site-specific fragmentation pathways are discovered involving peptide backbone cleavage, Tyr side chain loss, and N-terminal NH3 loss mediated by electron transfer. In YGGFL, IR excitation in the S1 state promotes electron transfer (ET) from the aromatic ring to the N-terminal R-NH3+ group leading to loss of neutral NH3. This product channel is missing in FGGYL due to the larger distance for ET from Y(4) to NH3+. Selective loss of the Tyr side chain occurs out of an excited state process following UV excitation and is further enhanced by IR excitation in S1 and Tn(v) states of both YGGFL and FGGYL. Finally, IR excitation in the S1 or Tn(v) states fragments the peptide backbone exclusively at amide(4), producing the b4 cation. We postulate that this selective fragmentation results from intersystem crossing to produce vibrationally excited triplets with enough energy to launch the proton along a proton conduit present in the known starting structure.
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Affiliation(s)
- Casey D Foley
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Chin Lee
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Ali Abou Taka
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Kendrew Au
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Etienne Chollet
- Department of Chemistry and Biochemistry, Fairfield University, Fairfield, Connecticut 06824, United States
| | - Matthew A Kubasik
- Department of Chemistry and Biochemistry, Fairfield University, Fairfield, Connecticut 06824, United States
| | - Laura M McCaslin
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
| | - Timothy S Zwier
- Gas Phase Chemical Physics, Sandia National Laboratories, Livermore, California 94550, United States
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3
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Hartmann JC, Madlener SJ, van der Linde C, Ončák M, Beyer MK. Magic cluster sizes of cationic and anionic sodium chloride clusters explained by statistical modeling of the complete phase space. Phys Chem Chem Phys 2024; 26:10904-10918. [PMID: 38525830 PMCID: PMC10989714 DOI: 10.1039/d4cp00357h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 03/11/2024] [Indexed: 03/26/2024]
Abstract
As one of the main components of sea salt aerosols, sodium chloride is involved in numerous atmospheric processes. Gas-phase clusters are ideal models to study fundamental physical and chemical properties of sodium chloride, which are significantly affected by the cluster size. Of particular interest are magic cluster sizes, which exhibit high intensities in mass spectra. In order to understand the origin of these magic cluster sizes, quantum chemical calculations at the CCSD(T)//DFT level are performed, yielding structures and binding energies of neutral (NaCl)x, anionic (NaCl)xCl- and cationic (NaCl)xNa+ clusters up to x = 8. Our calculations show that the clusters can easily isomerize, enabling dissociation into the lowest-energy isomers of the fragments. Energetics can explain the special stability of (NaCl)4Cl-, but (NaCl)4Na+ actually offers low-lying dissociation channels, despite being a magic cluster size. Collision-induced dissociation experiments reveal that the loss of neutral clusters (NaCl)x, x = 2, 4, is in most cases more favorable than the loss of NaCl or the atomic ion, i.e. sodium chloride clusters actually fragment via the cleavage of the entire cluster, not by evaporating small cluster building blocks. This is rationalized by the calculated high stability of even-numbered neutral clusters (NaCl)x, especially x = 2, 4. Analysis of the density of states and rate constants calculated with a modified Rice-Ramsperger-Kassel-Marcus (RRKM) equation called AWATAR - considering all energetically accessible isomers of reactants and fragments - shows that entropic effects are responsible for the magic cluster character of (NaCl)4Na+. In particular, low-lying vibrational modes provide a high density of states of the near-planar cluster. Together with the small contribution of an atomic ion to the sum of states in a loose transition state for dissociation, this leads to a very small unimolecular rate constant for dissociation into (NaCl)4 and Na+, which is the lowest energy fragmentation pathway. Thus, entropic effects may override energetics for certain magic cluster sizes.
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Affiliation(s)
- Jessica C Hartmann
- Universität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Sarah J Madlener
- Universität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Christian van der Linde
- Universität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Universität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Universität Innsbruck, Institut für Ionenphysik und Angewandte Physik, Technikerstraße 25, 6020 Innsbruck, Austria.
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4
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Bersenkowitsch NK, Madlener SJ, Heller J, van der Linde C, Ončák M, Beyer MK. Spectroscopy of cluster aerosol models: IR and UV spectra of hydrated glyoxylate with and without sea salt. ENVIRONMENTAL SCIENCE: ATMOSPHERES 2023; 3:1396-1406. [PMID: 38013930 PMCID: PMC10569154 DOI: 10.1039/d3ea00039g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/29/2023] [Indexed: 11/29/2023]
Abstract
Glyoxylic acid is formed in the troposphere by oxidation of organic molecules. In sea salt aerosols, it is expected to be present as glyoxylate, integrated into the salt environment and strongly interacting with water molecules. In water, glyoxylate is in equilibrium with its gem-diol form. To understand the influence of water and salt on the photophysics and photochemistry of glyoxylate, we generate small model clusters containing glyoxylate by electrospray ionization and study them by Fourier-Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry. We used infrared multiple photon dissociation spectroscopy and UV/vis photodissociation spectroscopy for structural characterization as well as quantum chemical calculations to model the spectra and dissociation patterns. Resonant absorption of infrared radiation leads to water evaporation, which indicates that water and glyoxylate are separate molecular entities in a significant fraction of the clusters, in line with the observed absorption of UV light in the actinic region. Hydration of glyoxylate leads to a change of the dihedral angle in the CHOCOO-·H2O complex, causing a slight redshift of the S1 ← S0 transition. However, the barriers for internal rotation are below 5 kJ mol-1, which explains the broad S1 ← S0 absorption extending from about 320 to 380 nm. Most importantly, hydration hinders dissociation in the S1 state, thus enhancing the quantum yield of fluorescence combined with water evaporation. No C-C bond photolysis is observed, but due to the limited signal-to-noise ratio, it cannot be ruled out. The quantum yield, however, will be relatively low. Fluorescence dominates the photophysics of glyoxylate embedded in the dry salt cluster, but the quantum yield shifts towards internal conversion upon addition of one or two water molecules.
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Affiliation(s)
- Nina K Bersenkowitsch
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Sarah J Madlener
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Jakob Heller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck Technikerstraße 25 6020 Innsbruck Austria
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck Technikerstraße 25 6020 Innsbruck Austria
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5
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Pritzi M, Pascher TF, Grutza ML, Kurz P, Ončák M, Beyer MK. Decomposition of Halogenated Molybdenum Sulfide Dianions [Mo 3S 7X 6] 2- (X = Cl, Br, I). JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1753-1760. [PMID: 35904429 PMCID: PMC9460775 DOI: 10.1021/jasms.2c00162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 05/26/2023]
Abstract
Molybdenum sulfides are considered a promising and inexpensive alternative to platinum as a catalyst for the hydrogen evolution reaction. In this study, we perform collision-induced dissociation experiments in the gas phase with the halogenated molybdenum sulfides [Mo3S7Cl6]2-, [Mo3S7Br6]2-, and [Mo3S7I6]2-. We show that the first fragmentation step for all three dianions is charge separation via loss of a halide ion. As a second step, further halogen loss competes with the dissociation of a disulfur molecule, whereas the former becomes energetically more favorable and the latter becomes less favorable from chlorine via bromine to iodine. We show that the leaving S2 group is composed of sulfur atoms from two bridging groups. These decomposition pathways differ drastically from the pure [Mo3S13]2- clusters. The obtained insight into preferred dissociation pathways of molybdenum sulfides illustrate possible reaction pathways during the activation of these substances in a catalytic environment.
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Affiliation(s)
- Marco Pritzi
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Tobias F. Pascher
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Marie-Luise Grutza
- Institut
für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Philipp Kurz
- Institut
für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Milan Ončák
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
| | - Martin K. Beyer
- Institut
für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
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6
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Pritzi M, Pascher TF, Grutza ML, Kurz P, Ončák M, Beyer MK. Rearrangement and decomposition pathways of bare and hydrogenated molybdenum oxysulfides in the gas phase. Phys Chem Chem Phys 2022; 24:16576-16585. [PMID: 35775378 DOI: 10.1039/d2cp01189a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molybdenum sulfides and molybdenum oxysulfides are considered a promising and cheap alternative to platinum as a catalyst for the hydrogen evolution reaction (HER). To better understand possible rearrangements during catalyst activation, we perform collision induced dissociation experiments in the gas phase with eight different molybdenum oxysulfides, namely [Mo2O2S6]2-, [Mo2O2S6]-, [Mo2O2S5]2-, [Mo2O2S5]-, [Mo2O2S4]-, [HMo2O2S6]-, [HMo2O2S5]- and [HMo2O2S4]-, on a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. We identify fragmentation channels of the molybdenum oxysulfides and their interconnections. Together with quantum chemical calculations, the results show that [Mo2O2S4]- is a particularly stable species against further dissociation, which is reached from all starting species with relatively low collision energies. Most interestingly, H atom loss is the only fragmentation channel observed for [HMo2O2S4]- at low collision energies, which relates to potential HER activity, since two such H atom binding sites on a surface may act together to release H2. The calculations reveal that multiple isomers are often very close in energy, especially for the hydrogenated species, i.e., atomic hydrogen can bind at various sites of the clusters. S2 groups play a decisive role in hydrogen adsorption. These are further features with potential relevance for HER catalysis.
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Affiliation(s)
- Marco Pritzi
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
| | - Tobias F Pascher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
| | - Marie-Luise Grutza
- Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Philipp Kurz
- Institut für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg, Germany
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
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7
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Marshall DL, Menzel JP, McKinnon BI, Blinco JP, Trevitt AJ, Barner-Kowollik C, Blanksby SJ. Laser Photodissociation Action Spectroscopy for the Wavelength-Dependent Evaluation of Photoligation Reactions. Anal Chem 2021; 93:8091-8098. [PMID: 34019383 DOI: 10.1021/acs.analchem.1c01584] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nitrile imine-mediated tetrazole-ene cycloaddition is a widely used class of photoligation. Optimizing the reaction outcome requires detailed knowledge of the tetrazole photoactivation profile, which can only partially be ascertained from absorption spectroscopy, or otherwise involves laborious reaction monitoring in solution. Photodissociation action spectroscopy (PDAS) combines the advantages of optical spectroscopy and mass spectrometry in that only absorption events resulting in a mass change are recorded, thus revealing the desired wavelength dependence of product formation. Moreover, the sensitivity and selectivity afforded by the mass spectrometer enable reliable assessment of the photodissociation profile even on small amounts of crude material, thus accelerating the design and synthesis of next-generation substrates. Using this workflow, we demonstrate that the photodissociation onset for nitrile imine formation is red-shifted by ca. 50 nm with a novel N-ethylcarbazole derivative relative to a phenyl-substituted archetype. Benchmarked against solution-phase tunable laser experiments and supported by quantum chemical calculations, these discoveries demonstrate that PDAS is a powerful tool for rapidly screening the efficacy of new substrates in the quest toward efficient visible light-triggered ligation for biological applications.
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Affiliation(s)
- David L Marshall
- Central Analytical Research Facility, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Jan P Menzel
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Benjamin I McKinnon
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - James P Blinco
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Adam J Trevitt
- Molecular Horizons and School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Christopher Barner-Kowollik
- Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Stephen J Blanksby
- Central Analytical Research Facility, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia.,Centre for Materials Science, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
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8
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Asymmetric Solvation of the Zinc Dimer Cation Revealed by Infrared Multiple Photon Dissociation Spectroscopy of Zn 2+(H 2O) n ( n = 1-20). Int J Mol Sci 2021; 22:ijms22116026. [PMID: 34199627 PMCID: PMC8199724 DOI: 10.3390/ijms22116026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/20/2021] [Accepted: 05/26/2021] [Indexed: 11/17/2022] Open
Abstract
Investigating metal-ion solvation—in particular, the fundamental binding interactions—enhances the understanding of many processes, including hydrogen production via catalysis at metal centers and metal corrosion. Infrared spectra of the hydrated zinc dimer (Zn2+(H2O)n; n = 1–20) were measured in the O–H stretching region, using infrared multiple photon dissociation (IRMPD) spectroscopy. These spectra were then compared with those calculated by using density functional theory. For all cluster sizes, calculated structures adopting asymmetric solvation to one Zn atom in the dimer were found to lie lower in energy than structures adopting symmetric solvation to both Zn atoms. Combining experiment and theory, the spectra show that water molecules preferentially bind to one Zn atom, adopting water binding motifs similar to the Zn+(H2O)n complexes studied previously. A lower coordination number of 2 was observed for Zn2+(H2O)3, evident from the highly red-shifted band in the hydrogen bonding region. Photodissociation leading to loss of a neutral Zn atom was observed only for n = 3, attributed to a particularly low calculated Zn binding energy for this cluster size.
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9
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Pascher TF, Ončák M, van der Linde C, Beyer MK. Spectroscopy and photochemistry of copper nitrate clusters. Phys Chem Chem Phys 2021; 23:9911-9920. [PMID: 33908510 DOI: 10.1039/d1cp00629k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The investigation of copper nitrate cluster anions Cu(ii)n(NO3)2n+1-, n ≤ 4, in the gas phase using ultraviolet/visible/near-infrared (UV/vis/NIR) spectroscopy provides detailed insight into the electronic structure of the copper salt and its intriguing photochemistry. In the experimentally studied region up to 5.5 eV, the spectra of copper(ii) nitrate exhibit a 3d-3d band in the vis/NIR and well-separated bands in the UV. The latter bands originate from Ligand-to-Metal Charge Transfer (LMCT) as well as n-π* transitions in the nitrate ligands. The clusters predominantly decompose by loss of neutral copper nitrate in the electronic ground state after internal conversion or via the photochemical loss of a neutral NO3 ligand after a LMCT. These two decomposition channels are in direct competition on the ground state potential energy surface for the smallest copper nitrate cluster, Cu(ii)(NO3)3-. Here, copper nitrate evaporation is thermochemically less favorable. Population of π* orbitals in the nitrate ligands may lead to N-O bond photolysis. This is observed in the UV region with a small quantum efficiency, with photochemical loss of either nitrogen dioxide or an oxygen atom.
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Affiliation(s)
- Tobias F Pascher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
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10
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Dörner S, Schwob L, Atak K, Schubert K, Boll R, Schlathölter T, Timm M, Bülow C, Zamudio-Bayer V, von Issendorff B, Lau JT, Techert S, Bari S. Probing Structural Information of Gas-Phase Peptides by Near-Edge X-ray Absorption Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:670-684. [PMID: 33573373 DOI: 10.1021/jasms.0c00390] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Near-edge X-ray absorption mass spectrometry (NEXAMS) is an action-spectroscopy technique of growing interest for investigations into the spatial and electronic structure of biomolecules. It has been used successfully to give insights into different aspects of the photodissociation of peptides and to probe the conformation of proteins. It is a current question whether the fragmentation pathways are sensitive toward effects of conformational isomerism, tautomerism, and intramolecular interactions in gas-phase peptides. To address this issue, we studied the cationic fragments of cryogenically cooled gas-phase leucine enkephalin ([LeuEnk+H]+) and methionine enkephalin ([MetEnk+H]+) produced upon soft X-ray photon absorption at the carbon, nitrogen, and oxygen K-edges. The interpretation of the experimental ion yield spectra was supported by density-functional theory and restricted-open-shell configuration interaction with singles (DFT/ROCIS) calculations. The analysis revealed several effects that could not be rationalized based on the peptide's amino acid sequences alone. Clear differences between the partial ion yields measured for both peptides upon C 1s → π*(C═C) excitations in the aromatic amino acid side chains give evidence for a sulfur-aromatic interaction between the methionine and phenylalanine side chain of [MetEnk+H]+. Furthermore, a peak associated with N 1s → π*(C═N) transitions, linked to a tautomeric keto-to-enol conversion of peptide bonds, was only present in the photon energy resolved ion yield spectra of [MetEnk+H]+.
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Affiliation(s)
- Simon Dörner
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Lucas Schwob
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Kaan Atak
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Kaja Schubert
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
| | - Rebecca Boll
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
- European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany
| | - Thomas Schlathölter
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Martin Timm
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Christine Bülow
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Vicente Zamudio-Bayer
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - Bernd von Issendorff
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - J Tobias Lau
- Abteilung Hochempfindliche Röntgenspektroskopie, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Strasse 3, 79104 Freiburg, Germany
| | - Simone Techert
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
- Institut für Röntgenphysik, Georg-August-Universität Göttingen, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
| | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg, Germany
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11
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Cunningham EM, Taxer T, Heller J, Ončák M, van der Linde C, Beyer MK. Microsolvation of Zn cations: infrared multiple photon dissociation spectroscopy of Zn +(H 2O) n (n = 2-35). Phys Chem Chem Phys 2021; 23:3627-3636. [PMID: 33524092 DOI: 10.1039/d0cp06112c] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structures, along with solvation evolution, of size-selected Zn+(H2O)n (n = 2-35) complexes have been determined by combining infrared multiple photon photodissociation (IRMPD) spectroscopy and density functional theory. The infrared spectra were recorded in the O-H stretching region, revealing varying shifts in band position due to different water binding motifs. Concordant with previous studies, a coordination number of 3 is observed, determined by the sudden appearance of a broad, red-shifted band in the hydrogen bonding region for clusters n > 3. The coordination number of 3 seems to be retained even for the larger clusters, due to incoming ligands experiencing significant repulsion from the Zn+ valence 4s electron. Evidence of spectrally distinct single- and double-acceptor sites are presented for medium-sized clusters, 4 ≤n≤ 7, however for larger clusters, n≥ 8, the hydrogen bonding region is dominated by a broad, unresolved band, indicative of the increased number of second and third coordination sphere ligands. No evidence of a solvated, six-fold coordinated Zn2+ ion/solvated electron pair is present in the spectra.
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Affiliation(s)
- Ethan M Cunningham
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
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12
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Zhang K, Ma L, Zhou M, Shi Y, Li S, Wang Y, Kong X. Wavelength-Dependent Ultraviolet Photodissociation of Protonated Tryptamine. J Phys Chem A 2020; 124:5280-5287. [PMID: 32536155 DOI: 10.1021/acs.jpca.0c02528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Ultraviolet photodissociation (UVPD) experiments of protonated tryptamine ([Tryp+H]+) have been implemented by a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer combined with a wavelength-tunable optical parametric oscillator (OPO) laser. UVPD mass spectra under different laser wavelengths have been obtained, in which the dependence of the yield of fragment ions on the laser wavelength was observed. The UVPD spectrum of [Tryp+H]+ has been obtained in the range of 210-310 nm. Besides the previously reported two competitive channels of H loss and NH3 loss, two important channels of losing CH2NH and CH2NH2 units were observed and further studied by UV-UV tandem mass spectrometry and theoretical calculations. Interestingly, results show that the pair of competitive channels of CH2NH loss and CH2NH2 loss are both from the McLafferty-type rearrangement caused by ππ* electronic excited states. After the excitation, the two different dissociation pathways produce two different ion-neutral complexes, respectively. The wavelength-dependent dissociation and the existing competitive channels shown in this study reflect the diversity of UVPD processes of such organic molecules.
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Affiliation(s)
- Kailin Zhang
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China.,State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Lifu Ma
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Min Zhou
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.,Department of Physics, Anhui Normal University, Wuhu 241000, China
| | - Yingying Shi
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Shuqi Li
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China
| | - Yan Wang
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin 300072, China
| | - Xianglei Kong
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China.,Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin 300071, China
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13
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Pascher TF, Ončák M, van der Linde C, Beyer MK. UV/Vis Spectroscopy of Copper Formate Clusters: Insight into Metal-Ligand Photochemistry. Chemistry 2020; 26:8286-8295. [PMID: 32155292 PMCID: PMC7384192 DOI: 10.1002/chem.202000280] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Indexed: 12/13/2022]
Abstract
The electronic structure and photochemistry of copper formate clusters, CuI2(HCO2)3− and CuIIn(HCO2)2n+1−, n≤8, are investigated in the gas phase by using UV/Vis spectroscopy in combination with quantum chemical calculations. A clear difference in the spectra of clusters with CuI and CuII copper ions is observed. For the CuI species, transitions between copper d and s/p orbitals are recorded. For stoichiometric CuII formate clusters, the spectra are dominated by copper d–d transitions and charge‐transfer excitations from formate to the vacant copper d orbital. Calculations reveal the existence of several energetically low‐lying isomers, and the energetic position of the electronic transitions depends strongly on the specific isomer. The oxidation state of the copper centers governs the photochemistry. In CuII(HCO2)3−, fast internal conversion into the electronic ground state is observed, leading to statistical dissociation; for charge‐transfer excitations, specific excited‐state reaction channels are observed in addition, such as formyloxyl radical loss. In CuI2(HCO2)3−, the system relaxes to a local minimum on an excited‐state potential‐energy surface and might undergo fluorescence or reach a conical intersection to the ground state; in both cases, this provides substantial energy for statistical decomposition. Alternatively, a CuII(HCO2)3Cu0− biradical structure is formed in the excited state, which gives rise to the photochemical loss of a neutral copper atom.
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Affiliation(s)
- Tobias F Pascher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
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14
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Bersenkowitsch NK, Ončák M, Heller J, Pascher TF, van der Linde C, Beyer MK. Evidence for lactone formation during infrared multiple photon dissociation spectroscopy of bromoalkanoate doped salt clusters. Phys Chem Chem Phys 2020; 22:12028-12038. [PMID: 32421138 PMCID: PMC7116335 DOI: 10.1039/d0cp00272k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction mechanisms of organic molecules in a salt environment are of
fundamental interest and are potentially relevant for atmospheric chemistry, in
particular sea-salt aerosols. Here, we found evidence for lactone formation upon
infrared multiple photon dissociation (IRMPD) of non-covalent bromoalkanoate
complexes as well as bromoalkanoate embedded in sodium iodide clusters. The
mechanism of lactone formation from bromoalkanoates of different chain lengths
is studied in the gas phase with and without salt environment by a combination
of IRMPD and quantum chemical calculations. IRMPD spectra are recorded in the
833-3846 cmT1 range by
irradiating the clusters with tunable laser systems while they are stored in the
cell of a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer.
The measurements of the binary complex
Br(CH2)mCOOH·Br(CH2)mCOO- for
m = 4 indicate valerolactone formation without salt
environment while lactone formation is hindered for longer chain lengths. When
embedded in sodium iodide clusters, butyrolactone formation from 4-bromobutyrate
seems to take place already during formation of the doped clusters in the
electrospray process, evidenced by the infrared (IR) signature of the lactone.
In contrast, IRMPD spectra of sodium iodide clusters containing 5-bromovalerate
contain signatures for both valerate as well as valerolactone. In both cases,
however, a neutral fragment corresponding to the mass of valerolactone is
eliminated, indicating that ring formation can be activated by IR light in the
salt cluster. Quantum chemical calculations show that already complexation with
one sodium ion significantly increases the barrier for lactone formation for all
chain lengths. IRMPD of sodium iodide clusters doped with neutral bromoalkanoic
acid molecules proceeds by elimination of HI or desorption of the intact acid
molecule from the cluster.
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Affiliation(s)
- Nina K Bersenkowitsch
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Jakob Heller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Tobias F Pascher
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
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15
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Schwob L, Dörner S, Atak K, Schubert K, Timm M, Bülow C, Zamudio-Bayer V, von Issendorff B, Lau JT, Techert S, Bari S. Site-Selective Dissociation upon Sulfur L-Edge X-ray Absorption in a Gas-Phase Protonated Peptide. J Phys Chem Lett 2020; 11:1215-1221. [PMID: 31978303 DOI: 10.1021/acs.jpclett.0c00041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Site-selective dissociation induced by core photoexcitation of biomolecules is of key importance for the understanding of radiation damage processes and dynamics and for its promising use as "chemical scissors" in various applications. However, identifying products of site-selective dissociation in large molecules is challenging at the carbon, nitrogen, and oxygen edges because of the high recurrence of these atoms and related chemical groups. In this paper, we present the observation of site-selective dissociation at the sulfur L-edge in the gas-phase peptide methionine enkephalin, which contains only a single sulfur atom. Near-edge X-ray absorption mass spectrometry has revealed that the resonant S 2p → σ*C-S excitation of the sulfur contained in the methionine side chain leads to site-selective dissociation, which is not the case after core ionization above the sulfur L-edge. The prospects of such results for the study of charge dynamics in biomolecular systems are discussed.
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Affiliation(s)
- Lucas Schwob
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Simon Dörner
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Kaan Atak
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Kaja Schubert
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
| | - Martin Timm
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Christine Bülow
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Vicente Zamudio-Bayer
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
| | - Bernd von Issendorff
- Physikalisches Institut , Universität Freiburg , Hermann-Herder-Straße 3 , 79104 Freiburg , Germany
| | - J Tobias Lau
- Abteilung für Hochempfindliche Röntgenspektroskopie , Helmholtz Zentrum Berlin für Materialien und Energie , Albert-Einstein-Strasse 15 , 12489 Berlin , Germany
- Physikalisches Institut , Universität Freiburg , Hermann-Herder-Straße 3 , 79104 Freiburg , Germany
| | - Simone Techert
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
- Institute of X-ray Physics , University of Göttingen , Friedrich-Hund-Platz 1 , 37077 Göttingen , Germany
| | - Sadia Bari
- Deutsches Elektronen-Synchrotron DESY , Notkestrasse 85 , 22607 Hamburg , Germany
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16
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Abstract
This paper is the fortieth consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2017 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY, 11367, United States.
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17
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Barwa E, Ončák M, Pascher TF, Herburger A, van der Linde C, Beyer MK. Infrared Multiple Photon Dissociation Spectroscopy of Hydrated Cobalt Anions Doped with Carbon Dioxide CoCO 2 (H 2 O) n - , n=1-10, in the C-O Stretch Region. Chemistry 2020; 26:1074-1081. [PMID: 31617628 PMCID: PMC7051846 DOI: 10.1002/chem.201904182] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Indexed: 11/05/2022]
Abstract
We investigate anionic [Co,CO2 ,nH2 O]- clusters as model systems for the electrochemical activation of CO2 by infrared multiple photon dissociation (IRMPD) spectroscopy in the range of 1250-2234 cm-1 using an FT-ICR mass spectrometer. We show that both CO2 and H2 O are activated in a significant fraction of the [Co,CO2 ,H2 O]- clusters since it dissociates by CO loss, and the IR spectrum exhibits the characteristic C-O stretching frequency. About 25 % of the ion population can be dissociated by pumping the C-O stretching mode. With the help of quantum chemical calculations, we assign the structure of this ion as Co(CO)(OH)2 - . However, calculations find Co(HCOO)(OH)- as the global minimum, which is stable against IRMPD under the conditions of our experiment. Weak features around 1590-1730 cm-1 are most likely due to higher lying isomers of the composition Co(HOCO)(OH)- . Upon additional hydration, all species [Co,CO2 ,nH2 O]- , n≥2, undergo IRMPD through loss of H2 O molecules as a relatively weakly bound messenger. The main spectral features are the C-O stretching mode of the CO ligand around 1900 cm-1 , the water bending mode mixed with the antisymmetric C-O stretching mode of the HCOO- ligand around 1580-1730 cm-1 , and the symmetric C-O stretching mode of the HCOO- ligand around 1300 cm-1 . A weak feature above 2000 cm-1 is assigned to water combination bands. The spectral assignment clearly indicates the presence of at least two distinct isomers for n ≥2.
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Affiliation(s)
- Erik Barwa
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Tobias F. Pascher
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Andreas Herburger
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
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18
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Pascher TF, Ončák M, van der Linde C, Beyer MK. Decomposition of Copper Formate Clusters: Insight into Elementary Steps of Calcination and Carbon Dioxide Activation. ChemistryOpen 2019; 8:1453-1459. [PMID: 31871848 PMCID: PMC6916659 DOI: 10.1002/open.201900282] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/13/2019] [Indexed: 11/29/2022] Open
Abstract
The decomposition of copper formate clusters is investigated in the gas phase by infrared multiple photon dissociation of Cu(II) n (HCO2)2n+1 -, n≤8. In combination with quantum chemical calculations and reactivity measurements using oxygen, elementary steps of the decomposition of copper formate are characterized, which play a key role during calcination as well as for the function of copper hydride based catalysts. The decomposition of larger clusters (n >2) takes place exclusively by the sequential loss of neutral copper formate units Cu(II)(HCO2)2 or Cu(II)2(HCO2)4, leading to clusters with n=1 or n=2. Only for these small clusters, redox reactions are observed as discussed in detail previously, including the formation of formic acid or loss of hydrogen atoms, leading to a variety of Cu(I) complexes. The stoichiometric monovalent copper formate clusters Cu(I) m (HCO2) m+1 -, (m=1,2) decompose exclusively by decarboxylation, leading towards copper hydrides in oxidation state +I. Copper oxide centers are obtained via reactions of molecular oxygen with copper hydride centers, species containing carbon dioxide radical anions as ligands or a Cu(0) center. However, stoichiometric copper(I) and copper(II) formate Cu(I)(HCO2)2 - and Cu(II)(HCO2)3 -, respectively, is unreactive towards oxygen.
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Affiliation(s)
- Tobias F. Pascher
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
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19
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Shi Y, Zhou M, Zhang K, Ma L, Kong X. Chiral Differentiation of Non-Covalent Diastereomers Based on Multichannel Dissociation Induced by 213-nm Ultraviolet Photodissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2297-2305. [PMID: 31410655 DOI: 10.1007/s13361-019-02302-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 07/10/2019] [Accepted: 07/23/2019] [Indexed: 06/10/2023]
Abstract
Here we present the implementation of 213-nm ultraviolet photodissociation (UVPD) in a FT-ICR mass spectrometer for chiral differentiation in the gas phase. The L/D amino acid-substituted serine octamer ions were selected as examples of diastereoisomers for chiral analysis. Several kinds of fragment ions were observed in these experiments, including fragment ions that are similar to the ones observed in corresponding collision-activated dissociation (CAD) experiments, fragment ions generated with different protonation sites by only destroying non-covalent bonds, and unique non-covalent cluster radical ions. The latter two kinds of fragment ions are found to be more sensitive to the chirality of the substituted units. Further experiments suggest that the formation of radical ions is mainly affected by chromophores on side chains of the substituted units and micro surroundings of the characterized non-covalent diastereoisomers. A comparing experiment performed by only changing the wavelength of UV laser to 266 nm shows that the 213-nm UV laser has the priority in the diversity of fragmentation pathways and potential of further application in chiral differentiation experiments.
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Affiliation(s)
- Yingying Shi
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
| | - Min Zhou
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
- Department of Physics, Anhui Normal University, Wuhu, 241000, People's Republic of China
| | - Kailin Zhang
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Lifu Ma
- School of Precision Instrument and Opto-Electronics Engineering, Tianjin University, Tianjin, 300072, China
| | - Xianglei Kong
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin, 300071, China.
- Collaborative Innovation Center of Chemical Science and Engineering, Nankai University, Tianjin, 300071, China.
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20
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Plattner M, Baloglou A, Ončák M, van der Linde C, Beyer MK. Structural Properties of Gas-Phase Molybdenum Oxide Clusters [Mo 4O 13] 2-, [HMo 4O 13] -, and [CH 3Mo 4O 13] - Studied by Collision-Induced Dissociation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1946-1955. [PMID: 31420847 PMCID: PMC6805806 DOI: 10.1007/s13361-019-02294-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 05/31/2023]
Abstract
Molybdenum oxide-based catalysts are widely used for the ammoxidation of toluene, methanation of CO, or hydrodeoxygenation. As a first step towards a gas-phase model system, we investigate here structural properties of mass-selected [Mo4O13]2-, [HMo4O13]-, and [CH3Mo4O13]- by a combination of collision-induced dissociation (CID) experiments and quantum chemical calculations. According to calculations, the common structural motif is an eight-membered ring composed of four MoO2 units and four O atoms. The 13th O atom is located above the center of the ring and connects two to four Mo centers. For [Mo4O13]2- and [HMo4O13]-, dissociation requires opening or rearrangement of the ring structure, which is quite facile for the doubly charged [Mo4O13]2-, but energetically more demanding for [HMo4O13]-. In the latter case, the hydrogen atom is found to stay preferentially with the negatively charged fragments [HMo2O7]- or [HMoO4]-. The doubly charged species [Mo4O13]2- loses one MoO3 unit at low energies while Coulomb explosion into the complementary fragments [Mo2O6]- and [Mo2O7]- dominates at elevated collision energies. [CH3Mo4O13]- affords rearrangements of the methyl group with low barriers, preferentially eliminating formaldehyde, while the ring structure remains intact. [CH3Mo4O13]- also reacts efficiently with water, leading to methanol or formaldehyde elimination.
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Affiliation(s)
- Manuel Plattner
- Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Aristeidis Baloglou
- Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020, Innsbruck, Austria.
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21
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Taxer T, Ončák M, Barwa E, van der Linde C, Beyer MK. Electronic spectroscopy and nanocalorimetry of hydrated magnesium ions [Mg(H 2O) n] +, n = 20-70: spontaneous formation of a hydrated electron? Faraday Discuss 2019; 217:584-600. [PMID: 30994636 PMCID: PMC6677030 DOI: 10.1039/c8fd00204e] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 12/07/2018] [Indexed: 11/26/2022]
Abstract
Hydrated singly charged magnesium ions [Mg(H2O)n]+ are thought to consist of an Mg2+ ion and a hydrated electron for n > 15. This idea is based on mass spectra, which exhibit a transition from [MgOH(H2O)n-1]+ to [Mg(H2O)n]+ around n = 15-22, black-body infrared radiative dissociation, and quantum chemical calculations. Here, we present photodissociation spectra of size-selected [Mg(H2O)n]+ in the range of n = 20-70 measured for photon energies of 1.0-5.0 eV. The spectra exhibit a broad absorption from 1.4 to 3.2 eV, with two local maxima around 1.7-1.8 eV and 2.1-2.5 eV, depending on cluster size. The spectra shift slowly from n = 20 to n = 50, but no significant change is observed for n = 50-70. Quantum chemical modeling of the spectra yields several candidates for the observed absorptions, including five- and six-fold coordinated Mg2+ with a hydrated electron in its immediate vicinity, as well as a solvent-separated Mg2+/e- pair. The photochemical behavior resembles that of the hydrated electron, with barrierless interconversion into the ground state following the excitation.
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Affiliation(s)
- Thomas Taxer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Erik Barwa
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
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22
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Pascher TF, Ončák M, van der Linde C, Beyer MK. Release of Formic Acid from Copper Formate: Hydride, Proton-Coupled Electron and Hydrogen Atom Transfer All Play their Role. Chemphyschem 2019; 20:1420-1424. [PMID: 30958610 PMCID: PMC6563433 DOI: 10.1002/cphc.201900095] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/22/2019] [Indexed: 01/27/2023]
Abstract
Although the mechanism for the transformation of carbon dioxide to formate with copper hydride is well understood, it is not clear how formic acid is ultimately released. Herein, we show how formic acid is formed in the decomposition of the copper formate clusters Cu(II)(HCOO)3- and Cu(II)2 (HCOO)5- . Infrared irradiation resonant with the antisymmetric C-O stretching mode activates the cluster, resulting in the release of formic acid and carbon dioxide. For the binary cluster, electronic structure calculations indicate that CO2 is eliminated first, through hydride transfer from formate to copper. Formic acid is released via proton-coupled electron transfer (PCET) to a second formate ligand, evidenced by close to zero partial charge and spin density at the hydrogen atom in the transition state. Concomitantly, the two copper centers are reduced from Cu(II) to Cu(I). Depending on the detailed situation, either PCET or hydrogen atom transfer (HAT) takes place.
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Affiliation(s)
- Tobias F. Pascher
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
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23
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Baloglou A, Ončák M, Grutza ML, van der Linde C, Kurz P, Beyer MK. Structural Properties of Gas Phase Molybdenum Sulfide Clusters [Mo 3S 13] 2-, [HMo 3S 13] -, and [H 3Mo 3S 13] + as Model Systems of a Promising Hydrogen Evolution Catalyst. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:8177-8186. [PMID: 30984322 PMCID: PMC6453024 DOI: 10.1021/acs.jpcc.8b08324] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/04/2018] [Indexed: 05/31/2023]
Abstract
Amorphous molybdenum sulfide (MoS x ) is a potent catalyst for the hydrogen evolution reaction (HER). Since mechanistic investigations on amorphous solids are particularly difficult, we use a bottom-up approach and study the [Mo3S13]2- nanocluster and its protonated forms. The mass selected pure [Mo3S13]2- as well as singly and triply protonated [HMo3S13]- and [H3Mo3S13]+ ions, respectively, were investigated by a combination of collision induced dissociation (CID) experiments and quantum chemical calculations. A rich variety of H x S y elimination channels was observed, giving insight into the structural flexibility of the clusters. In particular, it was calculated that the observed clusters tend to keep the Mo3 ring structure found in the bulk and that protons adsorb primarily on terminal disulfide units of the cluster. Mo-H bonds are formed only for quasi-linear species with Mo centers featuring empty coordination sites. Protonation leads to increased cluster stability against CID. The rich variety of CID dissociation products for the triply protonated [H3Mo3S13]+ ion, however, suggests that it has a large degree of structural flexibility, with roaming H/SH moieties, which could be a key feature of MoS x to facilitate HER catalysis via a Volmer-Heyrovsky mechanism.
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Affiliation(s)
- Aristeidis Baloglou
- Institut
für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Milan Ončák
- Institut
für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Marie-Luise Grutza
- Institut
für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - Christian van der Linde
- Institut
für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Philipp Kurz
- Institut
für Anorganische und Analytische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstraße 21, 79104 Freiburg, Germany
| | - Martin K. Beyer
- Institut
für Ionenphysik und Angewandte Physik, Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
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24
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Heller J, Ončák M, Bersenkowitsch NK, van der Linde C, Beyer MK. Infrared multiple photon dissociation of cesium iodide clusters doped with mono-, di- and triglycine. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2019; 25:122-132. [PMID: 30284923 PMCID: PMC7100558 DOI: 10.1177/1469066718803307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Charged cesium iodide clusters doped with mono-, di- and triglycine serve as a model system for sea salt aerosols containing biological molecules. Here, we investigate reactions of these complexes under infrared irradiation, with spectra obtained by infrared multiple photon dissociation. The cluster ions are generated via electrospray ionization and analyzed in the cell of a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer. Depending on the cluster size and peptide length, loss of HI or loss of a glycine unit is observed. The experimental measurements are supported by quantum chemical calculations. We show that N-H and O-H stretching modes dominate the spectrum, with large shifts depending on local interactions, namely due to interaction with iodide anions or intramolecular hydrogen bonding. Both experiment and theory indicate that several isomers are present in the experimental mixture, with different infrared fingerprints as well as dissociation pathways.
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Affiliation(s)
- Jakob Heller
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | - Nina K Bersenkowitsch
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
| | | | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
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25
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Bersenkowitsch NK, Ončák M, Heller J, van der Linde C, Beyer MK. Photodissociation of Sodium Iodide Clusters Doped with Small Hydrocarbons. Chemistry 2018; 24:12433-12443. [PMID: 29979470 PMCID: PMC6120481 DOI: 10.1002/chem.201803017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Indexed: 11/07/2022]
Abstract
Marine aerosols consist of a variety of compounds and play an important role in many atmospheric processes. In the present study, sodium iodide clusters with their simple isotope pattern serve as model systems for laboratory studies to investigate the role of iodide in the photochemical processing of sea-salt aerosols. Salt clusters doped with camphor, formate and pyruvate are studied in a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) coupled to a tunable laser system in both UV and IR range. The analysis is supported by ab initio calculations of absorption spectra and energetics of dissociative channels. We provide quantitative analysis of IRMPD measurements by reconstructing one-photon spectra and comparing them with the calculated ones. While neutral camphor is adsorbed on the cluster surface, the formate and pyruvate ions replace an iodide ion. The photodissociation spectra revealed several wavelength-specific fragmentation pathways, including the carbon dioxide radical anion formed by photolysis of pyruvate. Camphor and pyruvate doped clusters absorb in the spectral region above 290 nm, which is relevant for tropospheric photochemistry, leading to internal conversion followed by intramolecular vibrational redistribution, which leads to decomposition of the cluster. Potential photodissociation products of pyruvate in the actinic region may be formed with a cross section of <2×10-20 cm2 , determined by the experimental noise level.
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Affiliation(s)
- Nina K. Bersenkowitsch
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Jakob Heller
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
| | - Martin K. Beyer
- Institut für Ionenphysik und Angewandte PhysikUniversität InnsbruckTechnikerstraße 256020InnsbruckAustria
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26
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Ončák M, Taxer T, Barwa E, van der Linde C, Beyer MK. Photochemistry and spectroscopy of small hydrated magnesium clusters Mg +(H 2O) n, n = 1-5. J Chem Phys 2018; 149:044309. [PMID: 30068190 PMCID: PMC7075709 DOI: 10.1063/1.5037401] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Hydrated singly charged magnesium ions Mg+(H2O)n, n ≤ 5, in the gas phase are ideal model systems to study photochemical hydrogen evolution since atomic hydrogen is formed over a wide range of wavelengths, with a strong cluster size dependence. Mass selected clusters are stored in the cell of an Fourier transform ion cyclotron resonance mass spectrometer at a temperature of 130 K for several seconds, which allows thermal equilibration via blackbody radiation. Tunable laser light is used for photodissociation. Strong transitions to D1–3 states (correlating with the 3s-3px,y,z transitions of Mg+) are observed for all cluster sizes, as well as a second absorption band at 4–5 eV for n = 3-5. Due to the lifted degeneracy of the 3px,y,z energy levels of Mg+, the absorptions are broad and red shifted with increasing coordination number of the Mg+ center, from 4.5 eV for n = 1 to 1.8 eV for n = 5. In all cases, H atom formation is the dominant photochemical reaction channel. Quantum chemical calculations using the full range of methods for excited state calculations reproduce the experimental spectra and explain all observed features. In particular, they show that H atom formation occurs in excited states, where the potential energy surface becomes repulsive along the O⋅⋅⋅H coordinate at relatively small distances. The loss of H2O, although thermochemically favorable, is a minor channel because, at least for the clusters n = 1-3, the conical intersection through which the system could relax to the electronic ground state is too high in energy. In some absorption bands, sequential absorption of multiple photons is required for photodissociation. For n = 1, these multiphoton spectra can be modeled on the basis of quantum chemical calculations.
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Affiliation(s)
- Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Thomas Taxer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Erik Barwa
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria
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27
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Bersenkowitsch NK, Ončák M, van der Linde C, Herburger A, Beyer MK. Photochemistry of glyoxylate embedded in sodium chloride clusters, a laboratory model for tropospheric sea-salt aerosols. Phys Chem Chem Phys 2018; 20:8143-8151. [PMID: 29517776 PMCID: PMC5885371 DOI: 10.1039/c8cp00399h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although marine aerosols undergo extensive photochemical processing in the troposphere, a molecular level understanding of the elementary steps involved in these complex reaction sequences is still missing.
Although marine aerosols undergo extensive photochemical processing in the troposphere, a molecular level understanding of the elementary steps involved in these complex reaction sequences is still missing. As a defined laboratory model system, the photodissociation of sea salt clusters doped with glyoxylate, [NanCln–2(C2HO3)]+, n = 5–11, is studied by a combination of mass spectrometry, laser spectroscopy and ab initio calculations. Glyoxylate acts as a chromophore, absorbing light below 400 nm via two absorption bands centered at about 346 and 231 nm. Cluster fragmentation dominates, which corresponds to internal conversion of the excited state energy into vibrational modes of the electronic ground state and subsequent unimolecular dissociation. Photochemical dissociation pathways in electronically excited states include CO and HCO elimination, leading to [Nan–xCln–x–2HCOO]+ and [NanCln–2COO˙]+ with typical quantum yields in the range of 1–3% and 5–10%, respectively, for n = 5. The latter species contains CO2˙– stabilized by the salt environment. The comparison of different cluster sizes shows that the fragments containing a carbon dioxide radical anion appear in a broad spectral region of 310–380 nm. This suggests that the elusive CO2˙– species may be formed by natural processes in the troposphere. Based on the photochemical cross sections obtained here, the photolysis lifetime of glyoxylate in a dry marine aerosol is estimated as 10 h. Quantum chemical calculations show that dissociation along the C–C bond in glyoxylic acid as well as glyoxylate embedded in the salt cluster occurs after reaching the S1/S0 conical intersection, while this conical intersection is absent in free glyoxylate ions.
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Affiliation(s)
- Nina K Bersenkowitsch
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Milan Ončák
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Christian van der Linde
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Andreas Herburger
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
| | - Martin K Beyer
- Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
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28
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Becher S, Spengler B, Heiles S. Effects of wavelength, fluence, and dose on fragmentation pathways and photoproduct ion yield in 213 nm and 266 nm ultraviolet photodissociation experiments. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2018; 24:54-65. [PMID: 29141443 DOI: 10.1177/1469066717741747] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Ultraviolet photodissociation tandem mass spectrometry is a powerful tool to investigate the structure of biomolecules, due to its ability to generate rich fragmentation patterns or bond selective cleavage, as a function of used laser wavelength, laser fluence, dose (number of accumulated laser pulses), and available chromophores. Herein, we report first results obtained with a newly developed two-wavelength (266 nm and 213 nm) ultraviolet photodissociation setup coupled to a Fourier-transform ion cyclotron resonance mass spectrometer. Photoproduct yields for protonated 3-iodo-l-tyrosine were up to ∼75%. Dose and fluence dependent measurements for protonated 3-iodo-l-tyrosine, doubly charged protonated bradykinin and Fe(II) attached to 1,2-dioleoyl-sn-glycero-3-phosphocholine reveal that the ultraviolet photodissociation mechanism for photoproduct formation qualitatively differs between these model systems. Three derived photodissociation models were used to interpret the experimental results and show that while protonated 3-iodo-l-tyrosine and Fe(II) attached to 1,2-dioleoyl-sn-glycero-3-phosphocholine most likely dissociates via a single-photon process, fragmentation of doubly charged bradykinin ions was found to be most consistent with sequential two-photon dissociation (213 nm). The introduced dissociation models present an easy means to study the mechanism of ultraviolet photodissociation processes for a variety of analytes without prior knowledge of their photochemistry or to optimize experimental conditions by adjusting laser fluence or number of laser pulses.
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Affiliation(s)
- Simon Becher
- 426460 Institute of Inorganic and Analytical Chemistry, Justus Liebig University , Giessen, Germany
| | - Bernhard Spengler
- 426460 Institute of Inorganic and Analytical Chemistry, Justus Liebig University , Giessen, Germany
| | - Sven Heiles
- 426460 Institute of Inorganic and Analytical Chemistry, Justus Liebig University , Giessen, Germany
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29
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Menzel JP, Noble BB, Lauer A, Coote ML, Blinco JP, Barner-Kowollik C. Wavelength Dependence of Light-Induced Cycloadditions. J Am Chem Soc 2017; 139:15812-15820. [DOI: 10.1021/jacs.7b08047] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Jan P. Menzel
- School
of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
- Macromolecular
Architectures, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76131 Karlsruhe, Germany
| | - Benjamin B. Noble
- Australian
Research Council Centre of Excellence for Electromaterials Science,
Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Andrea Lauer
- School
of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
- Macromolecular
Architectures, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76131 Karlsruhe, Germany
- Institut
für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Michelle L. Coote
- Australian
Research Council Centre of Excellence for Electromaterials Science,
Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - James P. Blinco
- School
of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
| | - Christopher Barner-Kowollik
- School
of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology (QUT), 2 George Street, Brisbane, QLD 4000, Australia
- Macromolecular
Architectures, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76131 Karlsruhe, Germany
- Institut
für Biologische Grenzflächen, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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