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Dehn MH, Cao Y, Wang PX, Cottrell SP, MacLachlan MJ, Fleming DG, Kiefl RF. Direct observation of muonium reacting with uncapped gold nanoparticles in porous silica and nature of the final state. J Chem Phys 2020; 152:184706. [PMID: 32414252 DOI: 10.1063/5.0004210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report the reaction of muonium (Mu = [μ+e-]), a light isotopic analog of hydrogen, with uncapped gold nanoparticles embedded in mesoporous silica. Using the radio-frequency muon spin rotation (RF-μSR) technique, we directly observe and characterize the resulting final state on the nanoparticle surface, showing conclusively its diamagnetic nature. The magnetic environment experienced by the reacted muons is only weakly perturbed compared to that of muons in a silica reference, consistent with the surface of the gold nanoparticles being metallic and non-magnetic. We demonstrate the potential of RF-μSR for the investigation of the surface properties of nanoparticles and show the feasibility of Knight shift measurements of muons on metal surfaces.
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Affiliation(s)
- M H Dehn
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Y Cao
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - P-X Wang
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - S P Cottrell
- ISIS Facility, Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxon OX11 0QX, United Kingdom
| | - M J MacLachlan
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - D G Fleming
- TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - R F Kiefl
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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Fleming DG, Arseneau DJ, Cottrell SP, Peck JNT. Rate constants and kinetic isotope effects for H-atom abstraction reactions by muonium in the Mu + propane and Mu + n-butane reactions from 300 K to 435 K: challenges for theory. Phys Chem Chem Phys 2020; 22:6326-6334. [DOI: 10.1039/c9cp06822h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper reports measurements of the temperature dependence of the rate constants for H-atom abstraction reactions from propane and n-butane by the light isotopic H-atom muonium (Mu), kMu(T), over temperatures in the range 300 K to 435 K.
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Affiliation(s)
- Donald G. Fleming
- TRIUMF and Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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Arseneau DJ, Garner DM, Reid ID, Fleming DG. Muonium Addition Reactions and Kinetic Isotope Effects in the Gas Phase: k∞ Rate Constants for Mu + C2H2. J Phys Chem A 2015; 119:7247-56. [DOI: 10.1021/jp511604q] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Donald J. Arseneau
- TRIUMF and Department of
Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - David M. Garner
- TRIUMF and Department of
Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Ivan D. Reid
- TRIUMF and Department of
Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Donald G. Fleming
- TRIUMF and Department of
Chemistry, University of British Columbia, Vancouver, BC, Canada
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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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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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Fleming DG, Arseneau DJ, Sukhorukov O, Brewer JH, Mielke SL, Truhlar DG, Schatz GC, Garrett BC, Peterson KA. Kinetics of the reaction of the heaviest hydrogen atom with H2, the4Heμ + H2→4HeμH + H reaction: Experiments, accurate quantal calculations, and variational transition state theory, including kinetic isotope effects for a factor of 36.1 in isotopic mass. J Chem Phys 2011; 135:184310. [DOI: 10.1063/1.3657440] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Fleming DG, Bridges MD, Arseneau DJ, Chen YK, Wang YA. Isotope effects and the temperature dependences of the hyperfine coupling constants of muoniated sec-butyl radicals in condensed phases. J Phys Chem A 2011; 115:2778-93. [PMID: 21395224 DOI: 10.1021/jp109676b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reported here is the first μSR study of the muon (A(μ)) and proton (A(p)) β-hyperfine coupling constants (Hfcc) of muoniated sec-butyl radicals, formed by muonium (Mu) addition to 1-butene and to cis- and trans-2-butene. The data are compared with in vacuo spin-unrestricted MP2 and hybrid DFT/B3YLP calculations reported in the previous paper (I), which played an important part in the interpretation of the data. The T-dependences of both the (reduced) muon, A(μ)′(T), and proton, A(p)(T), Hfcc are surprisingly well explained by a simple model, in which the calculated Hfcc from paper I at energy minima of 0 and near ±120° are thermally averaged, assuming an energy dependence given by a basic 2-fold torsional potential. Fitted torsional barriers to A(μ)′(T) from this model are similar (~3 kJ/mol) for all muoniated butyl radicals, suggesting that these are dominated by ZPE effects arising from the C−Mu bond, but for A(p)(T) exhibit wide variations depending on environment. For the cis- and trans-2-butyl radicals formed from 2-butene, A(μ)′(T) exhibits clear discontinuities at bulk butene melting points, evidence for molecular interactions enhancing these muon Hfcc in the environment of the solid state, similar to that found in earlier reports for muoniated tert-butyl. In contrast, for Mu−sec-butyl formed from 1-butene, there is no such discontinuity. The muon hfcc for the trans-2-butyl radical are seemingly very well predicted by B3LYP calculations in the solid phase, but for sec-butyl from 1-butene, showing the absence of further interactions, much better agreement is found with the MP2 calculations across the whole temperature range. Examples of large proton Hfcc near 0 K are also reported, due to eclipsed C−H bonds, in like manner to C−Mu, which then also exhibit clear discontinuities in A(p)(T) at bulk melting points. The data suggest that the good agreement found between theory and experiment from the B3LYP calculations for eclipsed bonds in the solid phase may be fortuitous. For the staggered protons of the sec-butyl radicals formed, no discontinuities are seen at all in A(p)(T), also demonstrating no further effects of molecular interactions on these particular proton Hfcc.
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Affiliation(s)
- Donald G Fleming
- TRIUMF and Department of Chemistry, University of British Columbia, Vancouver, BC v6T 1Z1, Canada.
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Dilger H, Stolmár M, Tregenna-Piggott PL, Roduner E, Reid ID. Gas phase addition kinetics of the tert-butyl radical to oxygen. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19971010610] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Pan JJ, Arseneau DJ, Senba M, Garner DM, Fleming DG, Xie T, Bowman JM. Termolecular kinetics for the Mu+CO+M recombination reaction: A unique test of quantum rate theory. J Chem Phys 2006; 125:014307. [PMID: 16863298 DOI: 10.1063/1.2209679] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The room-temperature termolecular rate constants, k0, for the Mu + CO + M<==>MuCO + M (M = He, N2, Ar) recombination reaction have been measured by the muSR technique, and are reported for moderator gas pressures of up to approximately 200 bar (densities less, similar 0.4 x 10(22) molec cm(-3)). The experimental relaxation rates reveal an unusual signature, in being dominated by the electron spin-rotation interaction in the MuCO radical that is formed in the addition step. In N2 moderator, k0 = 1.2+/-0.1 x 10(-34) cm(6) s(-1), only about 30% higher than found in Ar or He. The experimental results are compared with theoretical calculations carried out on the Werner-Keller-Schinke (WKS) surface [Keller et al., J. Chem. Phys. 105, 4983 (1996)], within the framework of the isolated resonance model (IRM). The positions and lifetimes of resonance states are obtained by solving the complex Hamiltonian for the nonrotating MuCO system, using an L2 method, with an absorbing potential in the asymptotic region. Accurate values of the vibrational bound and resonance states of MuCO reveal unprecedented isotope effects in comparisons with HCO, due to the remarkable effect of replacing H by the very light Mu atom (m(Mu) approximately (1/9)m(H)). Due to its pronounced zero-point energy shift, there are only two (J = 0) bound states in MuCO. Contributions from nonzero J states to the termolecular rate constants are evaluated through the J-shifting approximation, with rotational constants evaluated at the potential minimum. The value of the important A constant (181 cm(-1)) used in this approximation was supported by accurate J = K = 1 calculations, from which A = 180 cm(-1) was obtained by numerical evaluation. The calculations presented here, with a "weak collision factor" beta c = 0.001, indicative of the very sparse density of MuCO states, give a very good account of both the magnitude and pressure dependence of the experimental rates, but only when the fact that the two initially bound (J = 0) states become resonances for J > 0 is taken into account. This is the first time in IRM calculations of atom-molecule recombination reactions where J not equal to 0 states have proven to be so important, thus providing a truly unique test of quantum rate theory.
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Affiliation(s)
- James J Pan
- TRIUMF and Department of Chemistry, University of British Columbia, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
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Ghandi K, Bridges MD, Arseneau DJ, Fleming DG. Muonium Formation as a Probe of Radiation Chemistry in Sub- and Supercritical Carbon Dioxide. J Phys Chem A 2004. [DOI: 10.1021/jp046166u] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Khashayar Ghandi
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Michael D. Bridges
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Donald J. Arseneau
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Donald G. Fleming
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
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Senba M, Fleming DG, Arseneau DJ, Mayne HR. Hot atom reaction yields in Mu*+H2 and T*+H2 from quasiclassical trajectory cross sections on the Liu–Siegbahn–Truhlar–Horowitz surface. J Chem Phys 2000. [DOI: 10.1063/1.481558] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Himmer U, Dilger H, Roduner E, Pan JJ, Arseneau DJ, Fleming DG, Senba M. Kinetic Isotope Effect in the Gas-Phase Reaction of Muonium with Molecular Oxygen. J Phys Chem A 1999. [DOI: 10.1021/jp984422v] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | | | | | | | - Masayoshi Senba
- Department of Physics, Dalhousie University, Halifax, NS, Canada, B3H 3J5
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Stadlbauer JM, Venkateswaran K, Porter GB, Walker DC. Fast Muonium Reactions in Solution: An Electron Spin Exchange Interaction with Cr(NCS)63- in Water and Reaction with Iodine in Organic Solvents. J Phys Chem A 1997. [DOI: 10.1021/jp970508x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- John M. Stadlbauer
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Krishnan Venkateswaran
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - Gerald B. Porter
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver V6T 1Z1, Canada
| | - David C. Walker
- Department of Chemistry and TRIUMF, University of British Columbia, Vancouver V6T 1Z1, Canada
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Fleming DG, Pan JJ, Senba M, Arseneau DJ, Kiefl RF, Shelley MY, Cox SFJ, Percival PW, Brodovitch J. Spin relaxation of muonium‐substituted ethyl radicals (MuCH2ĊH2) in the gas phase. J Chem Phys 1996. [DOI: 10.1063/1.472578] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Dilger H, Schwager M, Tregenna-Piggott PLW, Roduner E, Reid ID, Arseneau DJ, Pan JJ, Senba M, Shelley M, Fleming DG. Addition Kinetics and Spin Exchange in the Gas Phase Reaction of the Ethyl Radical with Oxygen. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp9525853] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | - Ivan D. Reid
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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Stallcop JR, Partridge H, Levin E. Ab initio potential-energy surfaces and electron-spin-exchange cross sections for H-O2 interactions. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1996; 53:766-771. [PMID: 9912948 DOI: 10.1103/physreva.53.766] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Senba M. Electron spin exchange with O2: Effects on the muon spin rotation, the electron spin resonance, and the positronium lifetime. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 52:4599-4615. [PMID: 9912799 DOI: 10.1103/physreva.52.4599] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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19
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Chemical reaction kinetics and Heisenberg spin exchange of the ethyl radical with oxygen. ACTA ACUST UNITED AC 1994. [DOI: 10.1007/bf02068480] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Sugai T, Sakamoto M, Matsushita A, Nishiyama K, Nagamine K, Kondow T. Studies on dynamics of Mu reaction with NO2 by muon spin resonance and relaxation techniques. J Chem Phys 1994. [DOI: 10.1063/1.467716] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Senba M. Muonium spin exchange in spin-polarized media: Spin-flip and -nonflip collisions. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1994; 50:214-227. [PMID: 9910885 DOI: 10.1103/physreva.50.214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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22
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Pan JJ, Senba M, Arseneau DJ, Kempton JR, Fleming DG, Baer S, Gonzalez AC, Snooks R. Muonium atom spin exchange with alkali-metal vapors: Mu+Cs. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1993; 48:1218-1226. [PMID: 9909725 DOI: 10.1103/physreva.48.1218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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23
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Matsushita A, Kadono R, Nishiyama K, Miyake Y, Nakao A, Takahashi J, Iwaki M, Nagamine K. Muonium formation on powdered platinum surfaces. Chem Phys Lett 1992. [DOI: 10.1016/0009-2614(92)85772-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sugai T, Kondow T, Matsushita A, Nishiyama K, Nagamine K. Direct observation of a diamagnetic product in gas-phase reactions of muonium by muon spin resonance. Chem Phys Lett 1992. [DOI: 10.1016/0009-2614(92)85095-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Reid ID, Roduner E. Structure and hyperfine coupling constants of radicals in muon-irradiated single-crystal naphthalene. Struct Chem 1991. [DOI: 10.1007/bf00672235] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Garner DM, Fleming DG, Arseneau DJ, Senba M, Reid ID, Mikula RJ. Muonium addition reactions in the gas phase: Quantum tunneling in Mu+C2H4 and Mu+C2D4. J Chem Phys 1990. [DOI: 10.1063/1.459099] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Turner RE, Snider RF, Fleming DG. Spin relaxation of hydrogen-atom isotopes via electron spin exchange with paramagnetic gases. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1990; 41:1505-1516. [PMID: 9903247 DOI: 10.1103/physreva.41.1505] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Gonzalez AC, Reid ID, Garner DM, Senba M, Fleming DG, Arseneau DJ, Kempton JR. Reaction kinetics of muonium with the halogen gases (F2, Cl2, and Br2). J Chem Phys 1989. [DOI: 10.1063/1.457435] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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