H-1 AND F-19 NMR-STUDIES ON MOLECULAR MOTIONS IN 2 SOLID-PHASES OF T-BUTYLAMMONIUM TETRAFLUOROBORATE

Differential thermal analysis (DTA), differential scanning calorimetry (DSC), and the temperature dependence of the spin-lattice relaxation time (T-1) and the second moment (M-2) of H-1 and F-19 NMR were studie d in (CH3)(3)CNH3BF4 and (CH3)(3)CND3BF4. DTA and DSC revealed a solid -solid phase transition at 219 K for (CH3)(3)CNH3BF4 and at 221 K for (CH3)(3)CND3BF4. The motions of cations and anions in the two solid ph ases were studied by T-1 and M-2 experiments. The motional modes of th e ions and their motional parameters were determined.