Wydział Chemii

Włodzimierz Masierak

M. Florek-Wojciechowska

I. Oglodek

Ryszard Jakubas

A. F. Privalov

B. Kresse

F. Fujara

Danuta Kruk

2015

Journal of Chemical Physics

142

204503/1- 204503/9

10.1063/1.4919966

Naukowa

Angielski

Artykuł

1H spin-lattice field cycling relaxation dispersion experiments in the intermediate phase II of the solid [C3H5N2]6[Bi4Br18] are presented. Two motional processes have been identified from the 1H 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 10−8 s-10−9 s and of about 10−5 s. Moreover, quadrupole relaxation enhancement (QRE) effects originating from slowly fluctuating 1H-14N dipolar interactions have been observed. From the positions of the relaxation maxima, the quadrupole coupling parameters for the 14N nuclei in [C3H5N2]6[Bi4Br18] have been determined. The 1H-14N 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.

http://dx.doi.org/10.1063/1.4919966

https://www.aip.org/