Solid-state H and C NMR studies of new ionic plastic-crystals with branched structures: [NEtMe(i-Pr)][BEtMe] ( = 1-3, = 0, 1).

Eight salts of [NEtMe(i-Pr)][BEtMe] ( = 1-3, = 0, 1) were prepared to reduce Coulombic interactions in the crystals. These novel ionic plastic crystals exhibited low activation energies for isotropic rotational motion () and ion diffusion (). The lattice constant in the cubic structure indexed to a CsCl-type was larger than that of the corresponding plastic crystals of [NEtMe][BEtMe] (nonbranched sample).