Zakład Fizyki Wysokich Ciśnień - publikacje

Abstract: Proton and fluorine second moments and spin-lattice relaxation times have been measured in a polycrystalline sample of trimethyloxosulphonium fluoroborate. Methyl groups execute threefold reorientation with an activation energy of 9.2+or-0.5 kJ mol-1. The activation energy for the threefold reorientation of the anion is 33+or-3 kJ in mol-1. The disorder of the BF4 - ion is dynamic. The ion jumps between two equilibrium orientations which have six fluorine and two boron equilibrium positions. The activation energy for this rotational-translational motion is 8.8+or-0.5 kJ mol-1. Further reorientations of the ion about its symmetry axes result in an isotropically reorienting ion. The activation energy for this motion is 17.6+or-0.8 kJ mol-1.