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The Boundary between Two Modes of Gas Evolution: Oscillatory (H2 and O2) and Conventional Redox (O2 Only), in the Hydrocarbon/H2O2/Cu(II)/CH3CN System. HYDROGEN 2023. [DOI: 10.3390/hydrogen4010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
During the oxidation of hydrocarbons using hydrogen peroxide solutions, the evolution of gaseous oxygen is a side and undesirable process, in which the consumption of the oxidizer is not associated with the formation of target products. Therefore, no attention is paid to the systematic study of the chemical composition of the gas and the mechanisms of its formation. Filling this gap, the authors discovered a number of new, previously unidentified, interesting facts concerning both gas evolution and the oxidation of hydrocarbons. In a 33% H2O2/Cu2Cl4·2DMG/CH3CN system, where DMG is dimethylglyoxime (Butane-2,3-dione dioxime), and is at 50 °C, evidence of significant evolution of gaseous hydrogen, along with the evolution of gaseous oxygen was found. In the authors’ opinion, which requires additional verification, the ratio of gaseous hydrogen and oxygen in the discussed catalytic system can reach up to 1:1. The conditions in which only gaseous oxygen is formed are selected. Using a number of oxidizable hydrocarbons with the first adiabatic ionization potentials (AIPs) of a wide range of values, it was found that the first stage of such a process of evolving only gaseous oxygen was the single electron transfer from hydrogen peroxide molecules to trinuclear copper clusters with the formation, respectively, of hydrogen peroxide radical cations H2O2•+ and radical anions Cu3Cl5•− (AIP = 5 eV). When the conditions for the implementation of such a single electron transfer mechanism are exhausted, the channel of decomposition of hydrogen peroxide molecules into gaseous hydrogen and oxygen is switched on, which is accompanied by the transition of the system to an oscillatory mode of gas evolution. In some cases, the formation of additional amounts of gaseous products is provided by the catalytically activated decomposition of water molecules into hydrogen and oxygen after the complete consumption of hydrogen peroxide molecules in the reaction of gaseous oxygen evolution. The adiabatic electron affinity of various forms of copper molecules involved in chemical processes is calculated by the density functional theory method.
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Schio L, Alagia M, Toffoli D, Decleva P, Richter R, Schalk O, Thomas RD, Mucke M, Salvador F, Bertoch P, Benedetti D, Dri C, Cautero G, Sergo R, Stebel L, Vivoda D, Stranges S. Photoionization Dynamics of the Tetraoxo Complexes OsO 4 and RuO 4. Inorg Chem 2020; 59:7274-7282. [PMID: 32343896 PMCID: PMC8007099 DOI: 10.1021/acs.inorgchem.0c00683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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The
photoionization dynamics of OsO4 and RuO4, chosen
as model systems of small-size mononuclear heavy-metal complexes,
has been theoretically studied by the time-dependent density functional
theory (TDDFT). Accurate experimental measurements of photoionization
dynamics as a benchmarking test for the theory are reported for the
photoelectron asymmetry parameters of outer valence ionizations of
OsO4, measured in the 17–90 eV photon energy range.
The theoretical results are in good agreement with the available experimental
data. The observed dynamical behavior of partial cross sections and
asymmetry parameters has been related to both the coupling to the
continuum of discrete excited states, giving strong modulations in
the photon energy dependency, and the atomic composition of the initial
ionized states, which determines the rate of decay of ionization probability
for increasing excitation energies. Overall, an extensive analysis
of the photoionization dynamics for valence and core orbitals is presented,
showing good agreement with all the available experimental data. This
provides confidence for the validity of the TDDFT approach in describing
photoionization of heavy transition element compounds, with the perspective
of being used for larger systems. Further experimental work is suggested
for RuO4 to gather evidence of the sensitivity of the theoretical
method to the nature of the metal atom. In this work,
the time-dependent density functional theory
is used to calculate the photoionization dynamics of the valence and
core ionizations of OsO4 and RuO4 complexes,
which are chosen as model systems of small-size mononuclear heavy-metal
complexes. Accurate experimental measurements of the branching ratios
and photoelectron asymmetry parameters of outer valence ionizations
of OsO4 provide a sound benchmark of the computational
methodology.
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Affiliation(s)
- Luca Schio
- SBAI Department, Sapienza University, P.le A. Moro 5, I-00185 Rome, Italy
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Michele Alagia
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Daniele Toffoli
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
| | - Piero Decleva
- Dipartimento di Scienze Chimiche e Farmaceutiche, Università degli Studi di Trieste, Via L. Giorgieri 1, I-34127 Trieste, Italy
| | - Robert Richter
- Elettra Sincrotrone Trieste, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Oliver Schalk
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Richard D. Thomas
- Department of Physics, Stockholm University, Roslagstullsbacken 21, 10691 Stockholm, Sweden
| | - Melanie Mucke
- Department of Physics and Astronomy, University of Uppsala, Box 516, SE-75120 Uppsala, Sweden
| | - Federico Salvador
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Paolo Bertoch
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Davide Benedetti
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Carlo Dri
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Giuseppe Cautero
- Elettra Sincrotrone Trieste, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Rudi Sergo
- Elettra Sincrotrone Trieste, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Luigi Stebel
- Elettra Sincrotrone Trieste, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Davide Vivoda
- Elettra Sincrotrone Trieste, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
| | - Stefano Stranges
- IOM-CNR Tasc, SS-14, Km 163.5, Area Science Park, Basovizza, I-34149 Trieste, Italy
- Department of Chemistry and Drug Technologies, Sapienza University, P.le A. Moro 5, I-00185 Rome, Italy
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Changala PB, Nguyen TL, Baraban JH, Ellison GB, Stanton JF, Bross DH, Ruscic B. Active Thermochemical Tables: The Adiabatic Ionization Energy of Hydrogen Peroxide. J Phys Chem A 2017; 121:8799-8806. [DOI: 10.1021/acs.jpca.7b06221] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- P. Bryan Changala
- JILA, National Institute of Standards and Technology and University of Colorado Boulder, Boulder, CO 80309, United States
| | - T. Lam Nguyen
- Quantum
Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, FL 32611, United States
| | - Joshua H. Baraban
- Department
of Chemistry, University of Colorado, Boulder, CO 80302, United States
| | - G. Barney Ellison
- Department
of Chemistry, University of Colorado, Boulder, CO 80302, United States
| | - John F. Stanton
- Quantum
Theory Project, Departments of Chemistry and Physics, University of Florida, Gainesville, FL 32611, United States
| | - David H. Bross
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, United States
| | - Branko Ruscic
- Chemical
Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439, United States
- Computation
Institute, The University of Chicago, Chicago, IL 60637, United States
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Falcinelli S, Alagia M, Farrar JM, Kalogerakis KS, Pirani F, Richter R, Schio L, Stranges S, Rosi M, Vecchiocattivi F. Angular and energy distributions of fragment ions in dissociative double photoionization of acetylene molecules in the 31.9-50.0 eV photon energy range. J Chem Phys 2016. [DOI: 10.1063/1.4962915] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Stefano Falcinelli
- Dipartimento di Ingegneria Civile ed Ambientale, Università di Perugia, 06125 Perugia, Italy
| | | | - James M. Farrar
- Department of Chemistry, University of Rochester, Rochester, New York 14627, USA
| | | | - Fernando Pirani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, 06123 Perugia, Italy
| | - Robert Richter
- Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy
| | - Luca Schio
- IOM CNR Laboratorio TASC, 34012 Trieste, Italy
| | - Stefano Stranges
- IOM CNR Laboratorio TASC, 34012 Trieste, Italy
- Dipartimento di Chimica e Tecnologia del Farmaco, Università di Roma “La Sapienza,” 00185 Rome, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile ed Ambientale, Università di Perugia, 06125 Perugia, Italy
| | - Franco Vecchiocattivi
- Dipartimento di Ingegneria Civile ed Ambientale, Università di Perugia, 06125 Perugia, Italy
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