Cationic motions studied by 1H and 2H-nuclear magnetic resonance, x-ray powder diffraction and thermal measurements in solid CH3(CH2)2NH3X, CH3(CH2)2ND3X and CD3(CH2)2NH3X (X = F, Cl, Br and I)

Dynamic behaviour of cations in propylammonium fluoride, chloride, bromide and iodide has been investigated by x-ray powder diffraction, thermal and H-1 and H-2 nuclear magnetic resonance measurements. The mobilities of the cations at room temperature were shown to be in the order iodide > bromide > chloride much greater than fluoride corresponding to the order of anion size. It was found that propylammonium fluoride has no rotator phase. In the highest-temperature phase in chloride, a highly disordered cationic state was obtained and the fluctuation angle of the cationic axis was estimated to be about 30degrees.