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Osior A, Kalicki P, Kamieński B, Szymański S, Bernatowicz P, Shkurenko A. Nonclassical dynamics of the methyl group in 1,1,1-triphenylethane. Evidence from powder 1H NMR spectra. J Chem Phys 2017; 146:104504. [PMID: 28298104 DOI: 10.1063/1.4978226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
According to the damped quantum rotation (DQR) theory, hindered rotation of methyl groups, evidenced in nuclear magnetic resonance (NMR) line shapes, is a nonclassical process. It comprises a number of quantum-rate processes measured by two different quantum-rate constants. The classical jump model employing only one rate constant is reproduced if these quantum constants happen to be equal. The values of their ratio, or the nonclassicallity coefficient, determined hitherto from NMR spectra of single crystals and solutions range from about 1.20 to 1.30 in the latter case to above 5.0 in the former, with the value of 1 corresponding to the jump model. Presently, first systematic investigations of the DQR effects in wide-line NMR spectra of a powder sample are reported. For 1,1,1-triphenylethane deuterated in the aromatic positions, the relevant line-shape effects were monitored in the range 99-121 K. The values of the nonclassicality coefficient dropping from 2.7 to 1.7 were evaluated in line shape fits to the experimental powder spectra from the range 99-108 K. At these temperatures, the fits with the conventional line-shape model are visibly inferior to the DQR fits. Using a theoretical model reported earlier, a semiquantitative interpretation of the DQR parameters evaluated from the spectra is given. It is shown that the DQR effects as such can be detected in wide-line NMR spectra of powdered samples, which are relatively facile to measure. However, a fully quantitative picture of these effects can only be obtained from the much more demanding experiments on single crystals.
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Affiliation(s)
- Agnieszka Osior
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Przemysław Kalicki
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Bohdan Kamieński
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Sławomir Szymański
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Piotr Bernatowicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Aleksander Shkurenko
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
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Cina JA. Bob, so far. A scientific biography of Robert A. Harris. Mol Phys 2006. [DOI: 10.1080/00268970500290300a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Ratajczyk T, Szymański S. Theory of damped quantum rotation in NMR spectra. I. Fundamental aspects. J Chem Phys 2005; 123:204509. [PMID: 16351283 DOI: 10.1063/1.2131868] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The damped quantum rotation (DQR) theory, formulated originally for methyl-like atomic groupings, is now extended to hindered (N>3)-fold molecular rotors, such as the cyclopentadienyl, benzene, and cycloheptatrienyl rings in solid phase environments. It heightens the significance of the Pauli principle in shaping up the stochastic dynamics of such objects, reflected in NMR line shapes. The corresponding NMR line-shape equation is derived; its stochastic part is shown for the first time to have the double commutator form for any values of the quantum-mechanical (coherence-damping) rate constants entering it. Constraints on the relative magnitudes of such constants are determined under which the DQR line-shape equation is converted into the phenomenological Alexander-Binsch equation describing classical jumps of the rotor. When all the quantum rate constants happen to be equal, the phenomenological model of equal jump rates between any two of the N (equivalent) orientations of the rotor is reproduced. On the other hand, the seemingly most plausible (for N>3) nearest-neighbor hopping model does not have any peculiar grounds in the DQR approach. For the special instances of stochastic molecular motions addressed in this work, the extended DQR formalism affords a quantification of the "degree of classicality" represented by a complete set of the relevant quantum rate constants. In view of our earlier experimental findings for the methyl rotors, the very occurrence of the nonclassical DQR effects seems unquestionable even for the objects of the size of benzene. The question of under what circumstances such effects can be big enough to be detected experimentally will be addressed in Part II of this work.
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Affiliation(s)
- T Ratajczyk
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warszawa, Poland
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Maseras F, Lledós A, Clot E, Eisenstein O. Transition metal polyhydrides: from qualitative ideas to reliable computational studies. Chem Rev 2000; 100:601-36. [PMID: 11749246 DOI: 10.1021/cr980397d] [Citation(s) in RCA: 312] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- F Maseras
- LSDSMS (UMR 5636) CC 014, Université de Montpellier II, 34095 Montpellier Cedex 05, France
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Szymański S. Nuclear magnetic resonance line shapes of methyl-like quantum rotors in low-temperature solids. J Chem Phys 1999. [DOI: 10.1063/1.479289] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Sabo-Etienne S, Chaudret B. Quantum Mechanical Exchange Coupling in Polyhydride and Dihydrogen Complexes. Chem Rev 1998; 98:2077-2092. [PMID: 11848960 DOI: 10.1021/cr9601066] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sylviane Sabo-Etienne
- Laboratoire de Chimie de Coordination CNRS, 205 Route de Narbonne, F-31077 Toulouse Cedex 4, France
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Limbach HH, Ulrich S, Gründemann S, Buntkowsky G, Sabo-Etienne S, Chaudret B, Kubas GJ, Eckert J. NMR and INS Line Shapes of Transition Metal Hydrides in the Presence of Coherent and Incoherent Dihydrogen Exchange. J Am Chem Soc 1998. [DOI: 10.1021/ja962903r] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hans-Heinrich Limbach
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Stefan Ulrich
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Stephan Gründemann
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Gerd Buntkowsky
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Sylviane Sabo-Etienne
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Bruno Chaudret
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Gregory J. Kubas
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
| | - Jürgen Eckert
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, Germany, the Laboratoire de Chimie de Coordination du CNRS (UP 8241), 205, route de Narbonne, F-31077 Toulouse-Cedex, France, and LANSCE, Los Alamos National Laboratory, Los Alamos, Mail Stop H805, New Mexico 87545
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Kuhlman R, Clot E, Leforestier C, Streib WE, Eisenstein O, Caulton KG. Quantum Exchange Coupling: A Hypersensitive Indicator of Weak Interactions. J Am Chem Soc 1997. [DOI: 10.1021/ja970603j] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Roger Kuhlman
- Contribution from the Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001, and Laboratoire de Chimie Théorique, Bâtiment 490, Université de Paris-Sud, 91405 Orsay, France
| | - Eric Clot
- Contribution from the Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001, and Laboratoire de Chimie Théorique, Bâtiment 490, Université de Paris-Sud, 91405 Orsay, France
| | - Claude Leforestier
- Contribution from the Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001, and Laboratoire de Chimie Théorique, Bâtiment 490, Université de Paris-Sud, 91405 Orsay, France
| | - William E. Streib
- Contribution from the Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001, and Laboratoire de Chimie Théorique, Bâtiment 490, Université de Paris-Sud, 91405 Orsay, France
| | - Odile Eisenstein
- Contribution from the Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001, and Laboratoire de Chimie Théorique, Bâtiment 490, Université de Paris-Sud, 91405 Orsay, France
| | - Kenneth G. Caulton
- Contribution from the Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, Indiana 47405-4001, and Laboratoire de Chimie Théorique, Bâtiment 490, Université de Paris-Sud, 91405 Orsay, France
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Buntkowsky G, Bargon J, Limbach HH. A Dynamic Model of Reaction Pathway Effects on Parahydrogen-Induced Nuclear Spin Polarization. J Am Chem Soc 1996. [DOI: 10.1021/ja954188b] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Gerd Buntkowsky
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, and Institut für Physikalische Chemie der Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
| | - Joachim Bargon
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, and Institut für Physikalische Chemie der Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
| | - Hans-Heinrich Limbach
- Contribution from the Institut für Organische Chemie der Freien Universität Berlin, Takustrasse 3, D-14195 Berlin, and Institut für Physikalische Chemie der Universität Bonn, Wegelerstrasse 12, D-53115 Bonn, Germany
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Szymański S. High-temperature quantum mechanical exchange of heavy particles. Effective spin Hamiltonian. J Mol Struct 1994. [DOI: 10.1016/0022-2860(93)08211-l] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Hiller EM, Harris RA. Bipolarons and the temperature dependence of exchange in the metal trihydrides. J Chem Phys 1994. [DOI: 10.1063/1.466500] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Hiller EM, Harris RA. Correlation and pairwise exchange in the metal trihydrides. J Chem Phys 1993. [DOI: 10.1063/1.465695] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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