1
|
Iwamoto Y, Tanimura Y. Linear absorption spectrum of a quantum two-dimensional rotator calculated using a rotationally invariant system-bath Hamiltonian. J Chem Phys 2018; 149:084110. [DOI: 10.1063/1.5044585] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yuki Iwamoto
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yoshitaka Tanimura
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Bernatowicz P, Shkurenko A, Osior A, Kamieński B, Szymański S. A quantum mechanical alternative to the Arrhenius equation in the interpretation of proton spin-lattice relaxation data for the methyl groups in solids. Phys Chem Chem Phys 2015; 17:28866-78. [PMID: 26451661 DOI: 10.1039/c5cp04924e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The theory of nuclear spin-lattice relaxation in methyl groups in solids has been a recurring problem in nuclear magnetic resonance (NMR) spectroscopy. The current view is that, except for extreme cases of low torsional barriers where special quantum effects are at stake, the relaxation behaviour of the nuclear spins in methyl groups is controlled by thermally activated classical jumps of the methyl group between its three orientations. The temperature effects on the relaxation rates can be modelled by Arrhenius behaviour of the correlation time of the jump process. The entire variety of relaxation effects in protonated methyl groups have recently been given a consistent quantum mechanical explanation not invoking the jump model regardless of the temperature range. It exploits the damped quantum rotation (DQR) theory originally developed to describe NMR line shape effects for hindered methyl groups. In the DQR model, the incoherent dynamics of the methyl group include two quantum rate (i.e., coherence-damping) processes. For proton relaxation only one of these processes is relevant. In this paper, temperature-dependent proton spin-lattice relaxation data for the methyl groups in polycrystalline methyltriphenyl silane and methyltriphenyl germanium, both deuterated in aromatic positions, are reported and interpreted in terms of the DQR model. A comparison with the conventional approach exploiting the phenomenological Arrhenius equation is made. The present observations provide further indications that incoherent motions of molecular moieties in the condensed phase can retain quantum character over much broader temperature range than is commonly thought.
Collapse
Affiliation(s)
- Piotr Bernatowicz
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Aleksander Shkurenko
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. and Functional Materials Design, Discovery and Development Research Group (FMD3), Advanced Membranes and Porous Materials Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Agnieszka Osior
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Bohdan Kamieński
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - Sławomir Szymański
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| |
Collapse
|
4
|
Szymański S. Spin-lattice relaxation of the methyl group protons in solids revisited: damped quantum rotation approach. J Chem Phys 2012; 137:034513. [PMID: 22830717 DOI: 10.1063/1.4734251] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Proton spin-lattice relaxation of the methyl group in solids had been one of the most thoroughly addressed theoretical problems in nuclear magnetic resonance (NMR) spectroscopy, considered at different levels of sophistication. For systems with substantial quantum tunneling effects, several quantum mechanical treatments were reported, although in practical applications the quantum models were always augmented with or replaced by the classical jump model. However, the latter has recently proved invalid in the description of NMR line shape effects in variable-temperature spectra of hindered methyl groups, while the competing theory of damped quantum rotation (DQR) was shown to be adequate. In this work, the spin-lattice relaxation issue for the methyl protons is readdressed using the latter theory. The main outcome is that, while the existing formulas for the relaxation rates remain unchanged, the crucial parameter entering them, the correlation time of the relevant random process, need to be reinterpreted. It proves to be the inverse of one of the two quantum-rate constants entering the DQR model, neither of which, when taken separately, can be related to the jump process. It can be identified with one describing the life-time broadening of the tunnel peaks in inelastic neutron scattering (INS) spectra of the methyl groups. Such a relationship between the relaxation and INS effects was reported from another laboratory long ago, but only for the low-temperature limit where thermal population of the excited torsional levels of the methyl group can be neglected. The whole spectrum of cases encountered in practical relaxation studies on protonated methyl groups is addressed for the first time. Preliminary experimental confirmation of this novel approach is reported, based on already published NMR data for a single crystal of methylmalonic acid. The once extensively debated issues of quenching of the coherent tunneling and of the classical limit in the dynamics of the methyl groups are readdressed and presented in a consistent manner.
Collapse
Affiliation(s)
- S Szymański
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland.
| |
Collapse
|
5
|
Došlić N, Gomzi V, Mališ M, Matanović I, Eckert J. Fluxionality of Hydrogen Ligands in Fe(H)2(H2)(PEtPh2)3. Inorg Chem 2011; 50:10740-7. [DOI: 10.1021/ic201248z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nađa Došlić
- Department of Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Vjeran Gomzi
- Department of Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Momir Mališ
- Department of Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Ivana Matanović
- Department of Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Juergen Eckert
- Materials Research Laboratory, University of California, Santa Barbara, California 93106, United States
| |
Collapse
|
6
|
Szymański S. Theory of damped quantum rotation in nuclear magnetic resonance spectra. III. Nuclear permutation symmetry of the line shape equation. J Chem Phys 2009; 131:244504. [PMID: 20059076 DOI: 10.1063/1.3276452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The damped quantum rotation (DQR) theory describes manifestations in nuclear magnetic resonance spectra of the coherent and stochastic dynamics of N-fold molecular rotors composed of indistinguishable particles. The standard jump model is only a limiting case of the DQR approach; outside this limit, the stochastic motions of such rotors have no kinematic description. In this paper, completing the previous two of this series, consequences of nuclear permutation symmetry for the properties of the DQR line shape equation are considered. The systems addressed are planar rotors, such as aromatic hydrocarbons' rings, occurring inside of molecular crystals oriented in the magnetic field. Under such conditions, oddfold rotors can have nontrivial permutation symmetries only for peculiar orientations while evenfold ones always retain their intrinsic symmetry element, which is rotation by 180 degrees about the N-fold axis; in specific orientations the latter can gain two additional symmetry elements. It is shown that the symmetry selection rules applicable to the classical rate processes in fluids, once recognized as having two diverse aspects, macroscopic and microscopic, are also rigorously valid for the DQR processes in the solid state. However, formal justification of these rules is different because the DQR equation is based on the Pauli principle, which is ignored in the jump model. For objects like the benzene ring, exploitation of these rules in simulations of spectra using the DQR equation can be of critical significance for the feasibility of the calculations. Examples of such calculations for the proton system of the benzene ring in a general orientation are provided. It is also shown that, because of the intrinsic symmetries of the evenfold rotors, many of the DQR processes, which such rotors can undergo, are unobservable in NMR spectra.
Collapse
Affiliation(s)
- S Szymański
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warszawa, Poland.
| |
Collapse
|
7
|
|
8
|
Ratajczyk T, Szymański S. Theory of damped quantum rotation in nuclear magnetic resonance spectra. II. Numerical simulations for the benzene rotor. J Chem Phys 2007; 127:184504. [DOI: 10.1063/1.2785180] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
9
|
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]
|
10
|
Colmenero J, Moreno AJ, Alegría A. Neutron scattering investigations on methyl group dynamics in polymers. Prog Polym Sci 2005. [DOI: 10.1016/j.progpolymsci.2005.08.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
11
|
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.
Collapse
Affiliation(s)
- T Ratajczyk
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warszawa, Poland
| | | |
Collapse
|
12
|
Free NH3 quantum rotations in Hofmann clathrates: structure factors and line widths studied by inelastic neutron scattering. Chem Phys 2005. [DOI: 10.1016/j.chemphys.2004.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
13
|
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.
Collapse
|
14
|
Birczyński A, Lalowicz Z, Łodziana Z. Rotational barriers in ammonium hexachlorometallates as studied by NMR, tunnelling spectroscopy and ab initio calculations. Chem Phys 2004. [DOI: 10.1016/j.chemphys.2003.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
15
|
Prager M, Schiebel P, Grimm H. Rotational tunneling of NH4 and NH3D and dipolar interaction in (NH3.6D0.4)2PtCl6. J Chem Phys 2002. [DOI: 10.1063/1.1477185] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
16
|
Würger A. Resonant coupling of free quantum rotors in inclusion compounds. PHYSICAL REVIEW LETTERS 2002; 88:063002. [PMID: 11863803 DOI: 10.1103/physrevlett.88.063002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2001] [Indexed: 05/23/2023]
Abstract
NH3 groups in certain Hofmann clathrates form almost free one-dimensional quantum rotors with energy levels E(n) = n(2)B and angular momentum n (planck constant), where n = 0, +/-1, +/-2,.... Recent neutron scattering experiments revealed a surprising temperature dependence for the linewidths of the n = 0 <--> 1, 0 <--> 2, and 1 <--> 2 transitions. We propose a novel line broadening mechanism based on rotor-rotor coupling and obtain a simple analytic expression for the widths that depends on the rotor level occupation and on the 3-proton spin degeneracies of initial and final states. Our model provides, without adjustable parameters, a good fit both to the temperature dependence of the observed widths and to their relative magnitude.
Collapse
Affiliation(s)
- Alois Würger
- Université Bordeaux 1, CPMOH, 351 cours de la Libération, 33405 Talence, France
| |
Collapse
|
17
|
Moreno AJ, Alegrı́a A, Colmenero J, Prager M, Grimm H, Frick B. Methyl group dynamics in glassy toluene: A neutron scattering study. J Chem Phys 2001. [DOI: 10.1063/1.1413742] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
18
|
Moreno AJ, Alegría A, Colmenero J, Frick B. Methyl Group Dynamics in Poly(methyl methacrylate): From Quantum Tunneling to Classical Hopping. Macromolecules 2001. [DOI: 10.1021/ma0100854] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. J. Moreno
- Departamento de Física de Materiales y Centro Mixto CSIC-UPV/EHU, Universidad del País Vasco (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
| | - A. Alegría
- Departamento de Física de Materiales y Centro Mixto CSIC-UPV/EHU, Universidad del País Vasco (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
| | - J. Colmenero
- Departamento de Física de Materiales y Centro Mixto CSIC-UPV/EHU, Universidad del País Vasco (UPV/EHU), Apartado 1072, 20080 San Sebastián, Spain
| | - B. Frick
- Institute Laue Langevin, BP 156X, F-38042 Grenoble, France
| |
Collapse
|
19
|
Szymański S, Olejniczak Z, Detken A, Haeberlen U. Iterative lineshape analysis of quadrupolar echo spectra of a damped CD(3) quantum rotor: preliminary evidence of a novel mechanism of stochastic spin exchange. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2001; 148:277-288. [PMID: 11237633 DOI: 10.1006/jmre.2000.2252] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
It is demonstrated that the wealth of information about damped quantum rotation of CD(3) groups, contained in quadrupolar echo spectra, can be fully explored in a broad temperature range using a method of iterative analysis of the spectral lineshapes. The recently reported lineshape equation which, apart from the quantum tunneling and the dissipative Alexander--Binsch terms, contains an additional dissipative term having no classical analog is shown to be capable of describing even subtle details of the spectra of a crystal of acetylsalicylic acid--CD(3) oriented specifically in the magnetic field. Preliminary evidence of the occurrence of this novel dissipative mechanism in the system studied is reported. The results obtained seem to suggest that there is no "classical limit" in the dissipative behavior of this system.
Collapse
Affiliation(s)
- S Szymański
- Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | | | | | | |
Collapse
|
20
|
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
|
21
|
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
| |
Collapse
|
22
|
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
| | | |
Collapse
|
23
|
Müser MH. The Path-Integral Monte Carlo of Rigid Linear Molecules in Three Dimensions. MOLECULAR SIMULATION 1996. [DOI: 10.1080/08927029608024102] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
24
|
|
25
|
Vibrational stimulation of the coherent tunneling transition in the cyclopentanone molecule. Russ Chem Bull 1994. [DOI: 10.1007/bf00700155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
26
|
|
27
|
Müser MH, Helbing W, Nielaba P, Binder K. Low-temperature anharmonic lattice deformations near rotator impurities: A quantum Monte Carlo approach. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1994; 49:3956-3962. [PMID: 9961684 DOI: 10.1103/physreve.49.3956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
28
|
Braun D, Weiss U. Dynamics of the damped rotational tunneling system: The effect of librational excitations. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf01320514] [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]
|
29
|
|
30
|
Buekenhoudt A. Temperature dependence of methyl reorientation at intermediate hindering potentials. PHYSICAL REVIEW. B, CONDENSED MATTER 1992; 46:5377-5386. [PMID: 10004318 DOI: 10.1103/physrevb.46.5377] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
31
|
Carlile C, Jamie I, Lockhart G, White J. Two-dimensional caesium-ammonia solid solutions in C28Cs(NH3)x. Mol Phys 1992. [DOI: 10.1080/00268979200101241] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
32
|
van der Putten D, Diezemann G, Fujara F, Hartmann K, Sillescu H. Methyl group dynamics in α‐crystallized toluene as studied by deuteron spin–lattice relaxation. J Chem Phys 1992. [DOI: 10.1063/1.462130] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
33
|
|
34
|
Bernhard T, Haeberlen U. Rotational tunneling of CD3 groups in the hydroquinone/methanol clathrate single-crystal and powder deuterium NMR spectra. Chem Phys Lett 1991. [DOI: 10.1016/s0009-2614(91)85147-o] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
35
|
Helbing W, Nielaba P, Binder K. Quantum Monte Carlo treatment of a rotator impurity in a crystal. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 44:4200-4205. [PMID: 10000068 DOI: 10.1103/physrevb.44.4200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
36
|
Börner K, Diezemann G, Rössler E, Vieth H. Low-temperature methyl group dynamics of hexamethylbenzene in crystalline and glassy matrices as studied by 2H NMR. Chem Phys Lett 1991. [DOI: 10.1016/0009-2614(91)80314-n] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
37
|
Idziak S, Haeberlen U, Zimmermann H. The configuration and the dynamics of the -CD3groups in methyl deuterated dimethylmalonic acid. Mol Phys 1991. [DOI: 10.1080/00268979100101391] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
38
|
|
39
|
Diezemann G, Sillescu H, van der Putten D. Spin lattice relaxation rates of tunnelling CD3 groups. ACTA ACUST UNITED AC 1991. [DOI: 10.1007/bf01309425] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
40
|
W�rger A, H�ller A. Rotational tunnelling: The width of the quasi-elastic line. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01313330] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
41
|
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]
|
42
|
|
43
|
H�ller A. Rotational tunnelling at finite temperatures: Substitution by an equivalent harmonic system. ACTA ACUST UNITED AC 1990. [DOI: 10.1007/bf01317364] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|