Dynamics of [C{sub 3}H{sub 5}N{sub 2}]{sub 6}[Bi{sub 4}Br{sub 18}] by means of {sup 1}H NMR relaxometry and quadrupole relaxation enhancement
- Department of Physics and Material Research, University of Economy, Garbary 2, 85-229 Bydgoszcz (Poland)
- Faculty of Food Sciences, University of Warmia and Mazury in Olsztyn, Oczapowskiego 7, 10719 Olsztyn (Poland)
- Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland)
- Faculty of Chemistry, University of Wroclaw, Joliot Curie 14, 50-383 Wroclaw (Poland)
- Institut für Festkörperphysik, TU Darmstadt, Hochschulstr. 6, 64289 Darmstadt (Germany)
{sup 1}H spin-lattice field cycling relaxation dispersion experiments in the intermediate phase II of the solid [C{sub 3}H{sub 5}N{sub 2}]{sub 6}[Bi{sub 4}Br{sub 18}] are presented. Two motional processes have been identified from the {sup 1}H spin-lattice relaxation dispersion profiles and quantitatively described. It has been concluded that these processes are associated with anisotropic reorientations of the imidazolium ring, characterized by correlation times of the order of 10{sup −8} s-10{sup −9} s and of about 10{sup −5} s. Moreover, quadrupole relaxation enhancement (QRE) effects originating from slowly fluctuating {sup 1}H-{sup 14}N dipolar interactions have been observed. From the positions of the relaxation maxima, the quadrupole coupling parameters for the {sup 14}N nuclei in [C{sub 3}H{sub 5}N{sub 2}]{sub 6}[Bi{sub 4}Br{sub 18}] have been determined. The {sup 1}H-{sup 14}N relaxation contribution associated with the slow dynamics has been described in terms of a theory of QRE [Kruk et al., Solid State Nucl. Magn. Reson. 40, 114 (2011)] based on the stochastic Liouville equation. The shape of the QRE maxima (often referred to as “quadrupole peaks”) has been consistently reproduced for the correlation time describing the slow dynamics and the determined quadrupole coupling parameters.
- OSTI ID:
- 22415876
- Journal Information:
- Journal of Chemical Physics, Vol. 142, Issue 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
Similar Records
Simple expressions of the nuclear relaxation rate enhancement due to quadrupole nuclei in slowly tumbling molecules
{sup 1}H relaxation dispersion in solutions of nitroxide radicals: Influence of electron spin relaxation