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Ghandi K, Landry C, Du T, Lainé M, Saul A, Le Caër S. Influence of confinement on free radical chemistry in layered nanostructures. Sci Rep 2019; 9:17165. [PMID: 31748626 PMCID: PMC6868163 DOI: 10.1038/s41598-019-52662-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 10/18/2019] [Indexed: 11/08/2022] Open
Abstract
The purpose of the present work was to study how chemical reactions and the electronic structure of atoms are affected by confinement at the sub-nanometer scale. To reach this goal, we studied the H atom in talc, a layered clay mineral. Talc is a highly 2D-confining material with the width of its interlayer space close to angstrom. We investigated talc with a particle accelerator-based spectroscopic method that uses elementary particles. This technique generates an exotic atom, muonium (Mu), which can be considered as an isotope of the H atom. Moreover, the technique allows us to probe a single atom (H atom) at any time and explore the effects of the layered clay on a single ion (proton) or atom. The cation/electron recombination happens in two time windows: one faster than a nanosecond and the other one at longer than microseconds. This result suggests that two types of electron transfer processes take place in these clay minerals. Calculations demonstrated that the interlayer space acts as a catalytic surface and is the primary location of cation/electron recombination in talc. Moreover, the studies of the temperature dependence of Mu decay rates, due to the formation of the surrogate of H2, is suggestive of an "H2" formation reaction that is thermally activated above 25 K, but governed by quantum diffusion below 25 K. The experimental and computational studies of the hyperfine coupling constant of Mu suggest that it is formed in the interlayer space of talc and that its electronic structure is extremely changed due to confinement. All these results imply that the chemistry could be strongly affected by confinement in the interlayer space of clays.
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Affiliation(s)
- Khashayar Ghandi
- University of Guelph, Department of chemistry, Guelph, ON, N1G 2W1, Canada.
| | - Cody Landry
- University of Guelph, Department of chemistry, Guelph, ON, N1G 2W1, Canada
| | - Tait Du
- Université de Sherbrooke, Faculté de médecine, Sherbrooke, QC, J1H 5N4, Canada
| | - Maxime Lainé
- LIONS, NIMBE, CEA, CNRS, Université Paris Saclay, CEA Saclay, F-91191, Gif-sur-Yvette, Cedex, France
| | - Andres Saul
- Aix-Marseille University, CINaM-CNRS UMR 7325 Campus de Luminy, F-13288, Marseille, Cedex 9, France
| | - Sophie Le Caër
- LIONS, NIMBE, CEA, CNRS, Université Paris Saclay, CEA Saclay, F-91191, Gif-sur-Yvette, Cedex, France
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Fleming DG, Cottrell SP, McKenzie I, Ghandi K. Rate constants for the slow Mu + propane abstraction reaction at 300 K by diamagnetic RF resonance. Phys Chem Chem Phys 2015; 17:19901-10. [DOI: 10.1039/c5cp02576a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The rate constant for the slow Mu + propane abstraction reaction has been determined by diamagnetic RF resonance. The curves show simulations of the μSR resonance signal. This study provides an important new test of reaction rate theory for the alkanes.
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Affiliation(s)
- Donald G. Fleming
- TRIUMF Laboratory and Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | | | - Iain McKenzie
- ISIS Facility
- STFC Rutherford Appleton Laboratory
- Didcot
- UK
- CMMS Facility
| | - Khashayar Ghandi
- Department of Chemistry and Biochemistry
- Mount Allison University
- Sackville
- Canada
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3
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Cormier PJ, Alcorn C, Legate G, Ghandi K. Muon radiolysis affected by density inhomogeneity in near-critical fluids. Radiat Res 2014; 181:396-406. [PMID: 24641627 DOI: 10.1667/rr13516.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In this article we show the significant tunability of radiation chemistry in supercritical ethane and to a lesser extent in near critical CO2. The information was obtained by studies of muonium (Mu = μ(+)e(-)), which is formed by the thermalization of positive muons in different materials. The studies of the proportions of three fractions of muon polarization, PMu, diamagnetic PD and lost fraction, PL provided the information on radiolysis processes involved in muon thermalization. Our studies include three different supercritical fluids, water, ethane and carbon dioxide. A combination of mobile electrons and other radiolysis products such as (•)C2H5 contribute to interesting behavior at densities ∼40% above the critical point in ethane. In carbon dioxide, an increase in electron mobility contributes to the lost fraction. The hydrated electron in water is responsible for the lost fraction and decreases the muonium fraction.
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Affiliation(s)
- P J Cormier
- Mount Allison University, New Brunswick, Canada
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Cormier PJ, Clarke RM, McFadden RML, Ghandi K. Selective free radical reactions using supercritical carbon dioxide. J Am Chem Soc 2014; 136:2200-3. [PMID: 24476090 DOI: 10.1021/ja408438s] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report herein a means to modify the reactivity of alkenes, and particularly to modify their selectivity toward reactions with nonpolar reactants (e.g., nonpolar free radicals) in supercritical carbon dioxide near the critical point. Rate constants for free radical addition of the light hydrogen isotope muonium to ethylene, vinylidene fluoride, and vinylidene chloride in supercritical carbon dioxide are compared over a range of pressures and temperatures. Near carbon dioxide's critical point, the addition to ethylene exhibits critical speeding up, while the halogenated analogues display critical slowing. This suggests that supercritical carbon dioxide as a solvent may be used to tune alkene chemistry in near-critical conditions.
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Affiliation(s)
- Philip J Cormier
- Department of Chemistry and Biochemistry, Mount Allison University , 63C York Street, Sackville, New Brunswick E4L 1G8, Canada
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Ghandi K, McFadden RML, Cormier PJ, Satija P, Smith M. Radical kinetics in sub- and supercritical carbon dioxide: thermodynamic rate tuning. Phys Chem Chem Phys 2012; 14:8502-5. [DOI: 10.1039/c2cp41170a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Fleming DG, Cottrell SP, McKenzie I, Macrae RM. New results for the formation of a muoniated radical in the Mu + Br2 system: a van der Waals complex or evidence for vibrational bonding in Br–Mu–Br? Phys Chem Chem Phys 2012; 14:10953-66. [DOI: 10.1039/c2cp41366c] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Chen YK, Fleming DG, Wang YA. Theoretical Calculations of Hyperfine Coupling Constants for Muoniated Butyl Radicals. J Phys Chem A 2011; 115:2765-77. [DOI: 10.1021/jp1096212] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ya Kun Chen
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Donald G. Fleming
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Yan Alexander Wang
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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Cormier P, Arseneau DJ, Brodovitch JC, Lauzon JM, Taylor BA, Ghandi K. Free Radical Formation in Supercritical CO2, Using Muonium as a Probe and Implication for H Atom Reaction with Ethene. J Phys Chem A 2008; 112:4593-600. [DOI: 10.1021/jp801023v] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- P. Cormier
- Department of Chemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada; TRIUMF, Vancouver, British Columbia, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - D. J. Arseneau
- Department of Chemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada; TRIUMF, Vancouver, British Columbia, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - J. C. Brodovitch
- Department of Chemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada; TRIUMF, Vancouver, British Columbia, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - J. M. Lauzon
- Department of Chemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada; TRIUMF, Vancouver, British Columbia, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - B. A. Taylor
- Department of Chemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada; TRIUMF, Vancouver, British Columbia, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - K. Ghandi
- Department of Chemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada; TRIUMF, Vancouver, British Columbia, Canada; Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
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Ghandi K, Clark IP, Lord JS, Cottrell SP. Laser-muon spin spectroscopy in liquids—A technique to study the excited state chemistry of transients. Phys Chem Chem Phys 2007; 9:353-9. [PMID: 17199151 DOI: 10.1039/b615184c] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This study introduces laser-muon spin spectroscopy in the liquid phase, which extends muonium chemistry in liquids to the realm of excited states and enables the detection of muoniated molecules by their spin evolution after laser excitation. This leads to new opportunities to study the Kinetic Isotope Effects (KIEs) of muonium/atomic hydrogen reactions and to probe transient chemistry in radiolysis processes involved in muonium formation, as well as muoniated intermediates in excited states.
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