6533b7d0fe1ef96bd125b71b

RESEARCH PRODUCT

The structure and phase transition of tris(n-propylammonium) enneachlorodiantimonate (III),

subject

description

The crystal structure of at 298 K has been determined (monoclinic, space group Cc, a = 19.464(2) ?, b = 17.736(2) ?, c = 8.116(2) ?, , Z = 4). The structure consists of one-dimensional polyanionic chains extended along the c-axis, and n-propylammonium cations located in elongated cavities formed by polyanions. The cations are connected to chlorine atoms by hydrogen bonds. Differential scanning calorimetry, the temperature dependence of the lattice parameters and static electric permittivity studies revealed a first-order phase transition at K of an `order - disorder' type. It is related to the ordering of n-propylammonium cations that occurs on decreasing the temperature. Debye-like dispersion of the electric permittivity between 30 MHz and 900 MHz is observed over a wide temperature range above . The activation energy of the reorientation of the n-propylammonium cations is found to be 0.29 eV.