M. Grottel et al., H-1 AND F-19 NMR-STUDY OF ION DYNAMICS IN TRIS-GUANIDINIUM HEPTAFLUOROZIRCONATE [C(NH2)(3)](3)ZRF7, Physica status solidi. b, Basic research, 207(2), 1998, pp. 333-339
Proton and fluorine NMR spectra and spin-lattice relaxation times were
measured for polycrystal line tris-guanidinium heptafluorozirconate i
n a wide temperature range. In-plane C-3 reorientation of the guanidin
ium cation hindered by the energy barrier E-a = 48.4 kJ/mol and isotro
pic reorientation of the fluoro-anion with the activation energy E-a =
38.8 kJ/mol have been revealed. At 467 K a solid-solid and at 541 K a
solid-liquid phase transition have been discovered.