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Kveder M, Rakvin B, You J. A quantum many body model for the embedded electron spin decoherence in organic solids. J Chem Phys 2019; 151:164124. [DOI: 10.1063/1.5124561] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Marina Kveder
- Division of Physical Chemistry, Ruder Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Boris Rakvin
- Division of Physical Chemistry, Ruder Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Jiangyang You
- Division of Physical Chemistry, Ruder Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
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Meier T, Petitgirard S, Khandarkhaeva S, Dubrovinsky L. Observation of nuclear quantum effects and hydrogen bond symmetrisation in high pressure ice. Nat Commun 2018; 9:2766. [PMID: 30018359 PMCID: PMC6050302 DOI: 10.1038/s41467-018-05164-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/15/2018] [Indexed: 11/19/2022] Open
Abstract
Hydrogen bond symmetrisations in H-bonded systems triggered by pressure-induced nuclear quantum effects (NQEs) is a long-known concept but experimental evidence in high-pressure ices has remained elusive with conventional methods. Theoretical works predicted quantum-mechanical tunneling of protons within water ices to occur at pressures above 30 GPa, and the H-bond symmetrisation transition to occur above 60 GPa. Here we used 1H-NMR on high-pressure ice up to 97 GPa, and demonstrate that NQEs govern the behavior of the hydrogen bonded protons in ice VII already at significantly lower pressures than previously expected. A pronounced tunneling mode was found to be present up to the highest pressures of 97 GPa, well into the stability field of ice X, where NQEs are not anticipated in a fully symmetrised H-bond network. We found two distinct transitions in the NMR shift data at about 20 GPa and 75 GPa attributed to the step-wise symmetrisation of the H-bond.
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Affiliation(s)
- Thomas Meier
- Bayerisches Geoinstitut, Bayreuth University, Universitätsstraße 30, 95447, Bayreuth, Germany.
| | - Sylvain Petitgirard
- Bayerisches Geoinstitut, Bayreuth University, Universitätsstraße 30, 95447, Bayreuth, Germany
| | - Saiana Khandarkhaeva
- Bayerisches Geoinstitut, Bayreuth University, Universitätsstraße 30, 95447, Bayreuth, Germany
| | - Leonid Dubrovinsky
- Bayerisches Geoinstitut, Bayreuth University, Universitätsstraße 30, 95447, Bayreuth, Germany
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Zhang B, Horsewill AJ. Methyl tunnelling sidebands in the low-field NMR spectrum of 3-pentanone: Driving A-E transitions using rf irradiation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2015; 258:33-39. [PMID: 26183303 DOI: 10.1016/j.jmr.2015.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/18/2015] [Accepted: 06/20/2015] [Indexed: 06/04/2023]
Abstract
Using magnetic field-cycling at cryogenic temperatures, low-field dipole-dipole driven NMR spectra have been recorded on 3-pentanone (CH3CH2C(O)CH2CH3). The spectra are characterised by tunnelling sidebands arising from the quantum dynamics of the methyl (CH3) rotors. From the sideband frequencies, the CH3 tunnelling frequency is determined to be νt=3.05±0.01MHz. The tunnelling sidebands are characterised by A-E transitions in nuclear spin-symmetry, involving simultaneous changes in tunnelling and nuclear spin states. To gain further insight, a theoretical analysis of the spin Hamiltonian matrix has been used to calculate the sideband transition probabilities. These are subsequently used in a thermodynamic model to simulate the low-field NMR spectrum which is compared with experiment. The level-crossings encountered as part of the magnetic field-cycling NMR sequence are found to play an essential role in determining the tunnelling sideband intensities.
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Affiliation(s)
- Bo Zhang
- School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Anthony J Horsewill
- School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
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Horsewill AJ, Goh K, Rols S, Ollivier J, Johnson MR, Levitt MH, Carravetta M, Mamone S, Murata Y, Chen JYC, Johnson JA, Lei X, Turro NJ. Quantum rotation and translation of hydrogen molecules encapsulated inside C₆₀: temperature dependence of inelastic neutron scattering spectra. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2013; 371:20110627. [PMID: 23918709 DOI: 10.1098/rsta.2011.0627] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The quantum dynamics of a hydrogen molecule encapsulated inside the cage of a C60 fullerene molecule is investigated using inelastic neutron scattering (INS). The emphasis is on the temperature dependence of the INS spectra which were recorded using time-of-flight spectrometers. The hydrogen endofullerene system is highly quantum mechanical, exhibiting both translational and rotational quantization. The profound influence of the Pauli exclusion principle is revealed through nuclear spin isomerism. INS is shown to be exceptionally able to drive transitions between ortho-hydrogen and para-hydrogen which are spin-forbidden to photon spectroscopies. Spectra in the temperature range 1.6≤T≤280 K are presented, and examples are given which demonstrate how the temperature dependence of the INS peak amplitudes can provide an effective tool for assigning the transitions. It is also shown in a preliminary investigation how the temperature dependence may conceivably be used to probe crystal field effects and inter-fullerene interactions.
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Affiliation(s)
- A J Horsewill
- School of Physics and Astronomy, University of Nottingham, , Nottingham NG7 2RD, UK.
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Horsewill AJ, Abu-Khumra SMM. Dynamic tunneling polarization as a quantum rotor analogue of dynamic nuclear polarization and the NMR solid effect. PHYSICAL REVIEW LETTERS 2011; 107:127602. [PMID: 22026802 DOI: 10.1103/physrevlett.107.127602] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Indexed: 05/31/2023]
Abstract
The populations of the tunneling states of CH(3) are manipulated by rf irradiation of weakly allowed sideband transitions within the manifold of tunneling-magnetic levels. Substantial positive and negative CH(3) tunneling polarizations are observed, providing a quantum rotor analogue of dynamic nuclear polarization and the solid effect in NMR. The field-cycling NMR technique used in the experiments employs level crossings between tunneling and Zeeman systems to report on the tunneling polarization. The tunneling lifetimes are measured and the field dependence investigated.
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Affiliation(s)
- A J Horsewill
- School of Physics and Astronomy, University of Nottingham, Nottingham, NG7 2RD, United Kingdom.
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Schurrer C, Pérez S, Wolfenson A. Proton resonance for oscillating field of the order of static magnetic field. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2010; 204:76-81. [PMID: 20207179 DOI: 10.1016/j.jmr.2010.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 02/03/2010] [Accepted: 02/06/2010] [Indexed: 05/28/2023]
Abstract
A spin decoupling method in nuclear quadrupole resonance spin echo experiment is used to detect the proton magnetic resonance absorption spectrum. The behavior of proton resonance in alpha phase of polycrystalline p-dichlorobenzene as a function of the intensity of the proton decoupling oscillating field (H(2)) is measured. Good agreement between the experimental resonance frequency and Shirley's theory for a non-interacting 1/2 spin system is observed. To our knowledge this is the first time the NMR proton frequency dependence on linear polarized excitation field intensity for H(2)/H(o) as high as 1.8 is measured.
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Affiliation(s)
- Clemar Schurrer
- Facultad de Matemática, Astronomia y Fisica, Universidad Nacional de Córdoba, IFEG-CONICET, Medina Allende s/n, Ciudad Universitaria, 5000 Córdoba, Argentina
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Sun C, Horsewill AJ. A field-cycling NMR investigation of resonant spin-lattice relaxation features arising from tunnelling methyl groups. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2009; 35:139-146. [PMID: 18951766 DOI: 10.1016/j.ssnmr.2008.08.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Revised: 08/27/2008] [Accepted: 08/28/2008] [Indexed: 05/27/2023]
Abstract
(1)H nuclear spin-lattice relaxation has been investigated in sodium acetate trihydrate and sorbic acid using field-cycling NMR in the solid state. The relaxation is dominated by the reorientation of the methyl groups. Resonant features arising from coherent tunnelling are observed in both the magnetic field dependence of the spin lattice relaxation rate, T(1)(-1)(B(z)) and in the inverse temperature dependence, T(1)(-1)(1/T). The two systems have different barrier heights and tunnelling frequencies, providing different perspectives on the tunnel resonance phenomena. The magnetic field dependence enables different spectral density components to be separately investigated and in the carboxylic acid, sorbic acid, concerted proton transfer in the hydrogen bonds is also identified at low field and low temperature. The methyl hindering barriers and the correlation times characterising the reorientational dynamics has been accurately determined in both materials.
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Affiliation(s)
- C Sun
- School of Physics & Astronomy, University of Nottingham, Nottingham, UK
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9
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Clough S, Horsewill A, Johnson M, Sutcliffe J, Tomsah I. Rotational quantization of methyl groups in a rotating frame. Mol Phys 2007. [DOI: 10.1080/00268979400100641] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Clough S, Horsewill A, Johnson M, Tomsah I. Resonant broadening of NMR line shapes of tunnelling methyl groups at level anticrossings. Mol Phys 2006. [DOI: 10.1080/00268979300100531] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- S. Clough
- a Department of Physics , University of Nottingham , NG7 2RD , UK
| | - A.J. Horsewill
- a Department of Physics , University of Nottingham , NG7 2RD , UK
| | - M.R. Johnson
- a Department of Physics , University of Nottingham , NG7 2RD , UK
| | - I.B.I. Tomsah
- a Department of Physics , University of Nottingham , NG7 2RD , UK
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11
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McDonald P, Pinter-Krainer M. High pressure NMR study of methyl group tunnelling in dimethyl sulphide. Mol Phys 2006. [DOI: 10.1080/00268979500100701] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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McDonald P, Vijayaraghavan D, Debenham P, Horsewill A. Pressure dependence of methyl tunnelling in solid diacetyl. Mol Phys 2006. [DOI: 10.1080/00268979300100181] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Gutsche P, Rinsdorf M, Zimmermann H, Schmitt H, Haeberlen U. The shape and information content of high-field solid-state proton NMR spectra of methyl groups. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2004; 25:227-240. [PMID: 15028273 DOI: 10.1016/s0926-2040(03)00061-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2003] [Indexed: 05/24/2023]
Abstract
The possible variation of the lineshape of the high-field 1H spectrum of methyl groups is explored by simulation and experiment. The spectrum of an isolated methyl group depends, apart from the orientation of the applied field B0 relative to the C3-axis of the group, on its rotational tunnel frequency vt and on its stochastic reorientation rate k. For quantitative analyses, the directional mobility of the C3-axis must also be taken into account. A distinct but frequently occurring case arises when the methyl groups come as pairs of magnetically equivalent close neighbours. For the experiments, single crystals of four compounds I-IV were grown that were isotopically substituted such that they contained protons only in the methyl positions. The crystal symmetry of all compounds I-IV allowed us to record spectra with all methyl groups being orientationally and otherwise equivalent. I, acetonitrile in deuterated hydroquinone, represents the case of a well-isolated methyl group with a "high" tunnel frequency vt. Its spectrum is (almost) independent of the temperature T. In II, monomethyl malonic acid, vt is comparable in size with the strength of the intramolecular dipolar H-H interaction. All seven theoretically expected lines in the 1H spectrum are clearly resolved in the spectra of II. vt can be inferred with an uncertainty of only +/- 300 Hz. vt(T) is found to possess a (flat) maximum near 40 K. Compound III, L-alanine, allows the study of the case of a methyl group with an extremely low, although nonzero tunnel frequency (vt approximately 3 kHz) while IV, dimethylglyoxime, represents the case of a close pair of equivalent methyl groups. Its spectrum reflects intriguing structural implications.
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Horsewill AJ, Xue Q. Magnetic field-cycling investigations of molecular tunnelling. Phys Chem Chem Phys 2002. [DOI: 10.1039/b206263a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Damyanovich A, Peternelj J, Pintar MM. Spectroscopy from proton spin magnetization evolution in their rotating frame: A study of small tunneling splitting. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 1999; 140:9-16. [PMID: 10479545 DOI: 10.1006/jmre.1999.1826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The time evolution of proton Zeeman magnetization in the rotating frame at exact resonance, omega = omega(0), is evaluated for an isolated tunneling methyl group CH(3). The Fourier transform of this evolution in time is calculated and both its real and imaginary components are presented. It is shown that the real component does not depend significantly on the strength of the preparation pulse when the tunneling splitting of the methyl rotator ground state is less than 100 kHz. It is also found that the imaginary component of the transform is inversely proportional to the strength of the preparation RF pulse. This is a consequence of the partial dephasing of proton spins during the preparation pulse. The results of the calculation compare well with the experimental spectra of CH(3)CD(2)I.
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Affiliation(s)
- A Damyanovich
- Department of Medical Imaging, University of Toronto, Toronto, Ontario, M5S 1A1, Canada
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Poplett IJ, Smith ME. Field sweep broadline NMR spectroscopy. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1998; 11:211-214. [PMID: 9694389 DOI: 10.1016/s0926-2040(97)00110-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A novel NMR spectrometer is described that is uniquely versatile in its ability to accurately record broad lines by sweeping the superconducting magnetic field and to perform standard high resolution solid state NMR experiments. Broadline observation is illustrated by 27Al spectra from static samples. Such an instrument opens up many nuclei for serious study by NMR in the solid state for the first time.
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Affiliation(s)
- I J Poplett
- School of Physical Sciences, University of Kent, Canterbury, UK
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Neumann M, Johnson M, Aibout A, Horsewill A. Measured and calculated rotational tunnelling dynamics in methyl acetate. Chem Phys 1998. [DOI: 10.1016/s0301-0104(98)00039-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Choi C, Damyanovich A, Peternel J, Pintar MM. Study of the NH4 tunneling manifold by energy level matching in the proton spin rotating frame. J Chem Phys 1998. [DOI: 10.1063/1.475798] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Prager M, Heidemann A. Rotational Tunneling and Neutron Spectroscopy: A Compilation. Chem Rev 1997; 97:2933-2966. [PMID: 11851482 DOI: 10.1021/cr9500848] [Citation(s) in RCA: 209] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Prager
- Institut Laue-Langevin, B.P. 156, F-38042 Grenoble, France
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Ibberson R, McDonald P, Pinter-Krainer M. The crystal structure determination of dimethylsulphide by high-resolution neutron powder diffraction. J Mol Struct 1997. [DOI: 10.1016/s0022-2860(97)00102-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Brougham D, Horsewill A, Jenkinson R. Proton transfer dynamics in the hydrogen bond: a direct measurement of the incoherent tunnelling rate by NMR and the quantum-to-classical transition. Chem Phys Lett 1997. [DOI: 10.1016/s0009-2614(97)00493-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Johnson M, Frick B, Trommsdorff H. A high resolution, inelastic neutron scattering investigation of tunnelling methyl groups in aspirin. Chem Phys Lett 1996. [DOI: 10.1016/0009-2614(96)00622-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Choi C, Pintar MM. Observation of CH3 tunneling manifold by level-crossing NMR. PHYSICAL REVIEW LETTERS 1996; 76:527-530. [PMID: 10061479 DOI: 10.1103/physrevlett.76.527] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Cleemput MV, Buekenhoudt A, Gerven LV, Horsewill AJ. Quantum and classical dynamics of a methyl group with tunneling frequency 3.4 MHz studied by low field NMR. J Chem Phys 1995. [DOI: 10.1063/1.470515] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jahnke TK, Müller-Warmuth W, Bennati M. Anomalous proton relaxation, rotational tunnelling and barriers to methyl group rotation in solid acetyl halides. SOLID STATE NUCLEAR MAGNETIC RESONANCE 1995; 4:153-161. [PMID: 7773648 DOI: 10.1016/0926-2040(94)00042-b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Rotational excitations of methyl groups attached to carbonyl in solid acetic acid, acetyl fluoride, acetyl chloride and acetyl bromide have been investigated by 1H nuclear magnetic resonance (NMR) relaxation times and field-cycling measurements at two frequencies and various temperatures. The tunnel splittings have been found to occur between 3.3 and 0.08 mu eV making quantum effects important for the relaxation behaviour. For the acetyl halides, similar tunnelling and NMR frequencies lead to an anomalous-looking temperature dependence of the relaxation rates. A consistent description by Haupt's equation is possible. The rotational potentials have been derived from the data and compared with those obtained from microwave spectra of the corresponding isolated molecules. The hindering potential is purely three-fold and the barrier is dominated by the functional group.
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Affiliation(s)
- T K Jahnke
- Institut für Physikalische Chemie der Westfälischen Wilhelms-Universität, Münster, Germany
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Horsewill AJ, McDonald PJ, Vijayaraghavan D. Hydrogen bond dynamics in benzoic acid dimers as a function of hydrostatic pressure measured by nuclear magnetic resonance. J Chem Phys 1994. [DOI: 10.1063/1.466541] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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2H NMR studies for the examination of methyl group rotations between their classical and quantum mechanical limits. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf01316710] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Black B, Majer G, Pines A. SQUID-NMR study of methyl quantum tunneling in a series of carboxylic acids. Chem Phys Lett 1993. [DOI: 10.1016/0009-2614(93)85115-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Benderskii VA, Goldanskii VI. Tunnelling of heavy particles in the low temperature chemistry. INT REV PHYS CHEM 1992. [DOI: 10.1080/01442359209353265] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ingman LP, Koivula E, Lalowicz ZT, Punkkinen M, Ylinen EE. 2H-NMR Study of ammonium ion rotational tunneling and reorientation in (ND4)2SnCl6 single crystal. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01309346] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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CONNOR C. Low-Frequency Magnetic Resonance with a dc SQUID. ADVANCES IN MAGNETIC AND OPTICAL RESONANCE 1990. [DOI: 10.1016/s1057-2732(13)70009-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Clough S, Barker GJ, Abed KJ, Horsewill AJ. Molecular friction and nuclear magnetism. PHYSICAL REVIEW LETTERS 1988; 60:136-139. [PMID: 10038218 DOI: 10.1103/physrevlett.60.136] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Ingman LP, Koivula E, Lalowicz ZT, Punkkinen M, Ylinen EE. 2H-NMR study of ammonium ion rotational tunneling and reorientation in (ND4)2SnCl6 single crystal: I. Tunneling frequency measurements. ACTA ACUST UNITED AC 1987. [DOI: 10.1007/bf01305428] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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40
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