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Hasiuk T, Jeffrey KR. (6)Li NMR in lithium borate glasses. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2008; 34:228-239. [PMID: 19081709 DOI: 10.1016/j.ssnmr.2008.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 09/02/2008] [Accepted: 09/26/2008] [Indexed: 05/27/2023]
Abstract
In anticipation of using fluctuations in the nuclear dipolar and quadrupolar interaction as a probe of lithium ion motion in lithium borate glasses, the static values of these interactions were measured using a variety of echo techniques. The static quadrupolar echo spectrum of (7)Li and a calculation of the dipolar interaction in crystalline Li(2)B(4)O(7) (same chemical composition as the glass under study) were used to estimate the strength of the two interactions. These indicate that the dipolar and quadrupolar interactions for (6)Li will be of similar size and the dipolar interaction will be dominated by the unlike spin interaction between the (6)Li and the (10)B, (11)B spins. An appropriate theoretical model is proposed and explicit expressions for the echo amplitude are calculated in terms of the dipolar and quadrupolar second moments. This single spin model takes into account the quadrupolar interaction but treats the dipolar interaction as an effective magnetic field. Experimental results are presented which show the essential validity of the model and measurements lead to reasonable values for the dipolar and quadrupolar second moments. The relative merits of the various echo techniques are discussed.
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Affiliation(s)
- Timothy Hasiuk
- Department of Physics, Guelph-Waterloo Physics Institute, University of Guelph, MacNaughton Building, Gordon Street, Guelph, Ontario, Canada N1G 2W1
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Domenici V, Frezzato D, Veracini CA. Slow Dynamics of Banana-Shaped Molecules: A Theoretical Approach to Analyze 2H-NMR T2 Relaxation Times. J Phys Chem B 2006; 110:24884-96. [PMID: 17149909 DOI: 10.1021/jp063442r] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the present work, we analyze pulsed deuterium NMR experiments performed on the isotropic and nematic phases of the banana-shaped liquid-crystalline mesogen 4-chloro-1,3-phenylene bis{4-4'-(11-undecenyloxy) benzoyloxy} benzoate (ClPbis11BB) selectively deuterated on the central ring. Starting from a previous evidence of unusual slow dynamics in the isotropic phase (Domenici V. et al., J. Phys. Chem. B 2005, 109, 769), a quantitative and model-supported analysis of the deuterium NMR data is performed here by accounting for slow-motional modulation of the magnetic anisotropies through the full solution of the stochastic Liouville equation. Focusing on the quadrupolar echo experiments performed in the nematic phase, the analysis of the transverse relaxation rate has been carried out by considering single-molecule motions and fluctuations of the local director. The main conclusions are: (a) director fluctuations are not relevant on driving the signal relaxation; (b) molecular reorientations about transverse axes control the dynamic regime of the signal relaxation and impose a full slow-motional treatment; (c) the small amplitude tumbling of the molecule within the wells of orientational potential occurs with characteristic times up to the microsecond. The outcome of our analysis has to be taken as indicative of very slow dynamics concerning out-of-plane motions of the molecules. Besides the specific application, this paper also offers the methodological tools to treat the pulsed deuterium NMR experiment in the slow-motional regime of reorientational motions and provides a detailed comparison with the usually employed fast-motional approximation.
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Affiliation(s)
- Valentina Domenici
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, 56126, Pisa, Italy.
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Boden N, Clark L, Clarke C, Kahol P. N.M.R. solid echoes in systems of coupled pairs of spins-1/2. Mol Phys 2006. [DOI: 10.1080/00268978300102621] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Boden N, Clark L, Bushby R, Emsley J, Luckhurst G, Stockley C. A deuterium N.M.R. study of chain ordering in the liquid crystals 4,4′-di-n-heptyloxyazoxybenzene and 4-n-octyl-4′-cyanobiphenyl. Mol Phys 2006. [DOI: 10.1080/00268978100100471] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- N. Boden
- a Department of Chemistry , The University , Leeds , LS2 9JT , England
| | - L.D. Clark
- a Department of Chemistry , The University , Leeds , LS2 9JT , England
| | - R.J. Bushby
- a Department of Chemistry , The University , Leeds , LS2 9JT , England
| | - J.W. Emsley
- b Department of Chemistry , The University , Southampton , SO9 5NH , England
| | - G.R. Luckhurst
- b Department of Chemistry , The University , Southampton , SO9 5NH , England
| | - C.P. Stockley
- b Department of Chemistry , The University , Southampton , SO9 5NH , England
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Qi F, Diezemann G, Böhm H, Lambert J, Böhmer R. Simple modeling of dipolar coupled 7Li spins and stimulated-echo spectroscopy of single-crystalline beta-eucryptite. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2004; 169:225-39. [PMID: 15261617 DOI: 10.1016/j.jmr.2004.04.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2004] [Revised: 04/21/2004] [Indexed: 05/20/2023]
Abstract
Stimulated-echo spectroscopy has recently been applied to study the ultra-slow dynamics of nuclear spin-3/2 probes such as 7Li and 9Be in solids. Apart from the dominant first-order quadrupolar interaction in the present article also the impact of the homonuclear dipolar interactions is considered in a simple way: the time evolution of a dipole coupled pair of spins with I = 3/2 is calculated in an approximation, which takes into account that the satellite transitions usually do not overlap. Explicit analytical expressions describing various aspects of a coupled quadrupolar pair subjected to a Jeener-Broekaert pulse sequence are derived. Extensions to larger spin systems are also briefly discussed. These results are compared with experimental data on a single-crystalline Li ion conductor.
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Affiliation(s)
- F Qi
- Experimentelle Physik III, Universität Dortmund, Germany
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Qi F, Jörg T, Böhmer R. Stimulated-echo NMR spectroscopy of 9Be and 7Li in solids: method and application to ion conductors. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2002; 22:484-500. [PMID: 12539972 DOI: 10.1006/snmr.2002.0073] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The generation of pure quadrupolar stimulated-echo spectra is successfully demonstrated for the spin-3/2 probe 9Be in a single crystal of triglycine fluoberyllate. This solid exhibits a paraelectric-to-ferroelectric phase transition. From experiments carried out for various mixing times no indications for a slow soft mode could be detected in this crystal. Then ion conducting lithium metal phosphates were studied using 7Li, another spin-3/2 probe which allows for a non-selective excitation of the entire NMR spectrum. In the indium and the scandium phosphates ultra-slow Li hopping processes could be detected directly via the stimulated-echo technique in a time range of up to four orders of magnitude. Due to the relatively large gyromagnetic ratio and thus strong dipolar interactions of 7Li no pure quadrupolar echoes could be generated. However, from a variation of the evolution times the quadrupolar effects could be separated from the dipolar ones. Finally, the differences in the ion hopping times of lithium indium phosphate and of lithium scandium phosphate are briefly discussed.
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Affiliation(s)
- F Qi
- Experimentelle Physik III, Universität Dortmund, 44221 Dortmund, Germany
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Kircher O, Diezemann G, Böhmer R, Hinze G, Schug KU, Sillescu H, Zimmermann H. Decay of single and double quantum coherences in deuterated glassy ortho-terphenyl. J Chem Phys 1998. [DOI: 10.1063/1.476284] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Diezemann G, Sillescu H. Dipolar interactions in deuteron spin systems. II. Transverse relaxation. J Chem Phys 1995. [DOI: 10.1063/1.470418] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Heaton N, Reimer D, Kothe G. Transverse deuteron spin relaxation in thermotropic liquid crystal polymers: determination of viscoelastic properties. Chem Phys Lett 1992. [DOI: 10.1016/0009-2614(92)85632-k] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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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]
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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]
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Kahol P, Boden N. N.M.R. solid echoes in systems of dipolar-coupled inequivalent spins-1 or dipolar-coupled inequivalent pairs of spins-1/2. Mol Phys 1990. [DOI: 10.1080/00268979000100631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Heaton NJ, Vold RR, Vold RL. Heteronuclear dipolar dephasing of deuterium quadrupole echoes. J Chem Phys 1989. [DOI: 10.1063/1.457441] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Deuterium Nuclear Magnetic Resonance and Molecular Dynamics in Alkane/Urea Inclusion Compounds. ACTA ACUST UNITED AC 1989. [DOI: 10.1016/b978-0-12-025513-9.50007-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Barton W, Lynch L. Two-pulse NMR techniques for studying proton-unpaired electron interactions in coals and chars. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0022-2364(88)90003-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Boden N, Clark L, Kahol P. NMR “solid” echoes in nematic 4-cyano-4′-n-penyl-d11-2′,3′,5′,6′-d4-biphenyl. Chem Phys Lett 1982. [DOI: 10.1016/0009-2614(82)85063-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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