Synthesis, crystal structure, NMR study and AC conductivity of [(C3H7)4N]2Cd2ClF5 compound

Abstract

The [(C3H7)4N]2Cd2ClF5 compound was crystallized in the triclinic system with space group P1. The crystal structure consists of organic–inorganic layers, stacked along $$[0\bar{1}1]$$ direction. The organic part consists of two cations types. The inorganic layer is made up of Cd2ClF5 dimmers composed of two in-equivalent irregular tetrahedra sharing one edge (Cl–F). The MAS NMR spectra showed two, three and five isotropic resonances relative to 111Cd, 13C and 19F nuclei, respectively. DSC measurement disclosed a phase transition at around 380 K. The impedance spectroscopy and AC electrical conductivity measurements of our compound were taken from 209 Hz to 5 MHz over the temperature range of 350–381 K. Nyquist plots (Z″ vs Z′) show semicircle arcs at different temperatures, and an electrical equivalent circuit has been proposed to explain the impedance results. The circuits consist of the parallel combination of bulk resistance (R), capacitance (C) and fractal capacitance (CPE). The conductivity σ p follows the Arrhenius relation. The near value of activation energies obtained from the conductivity data and circuit equivalent confirms that the transport is through hopping mechanism. The analysis of the experimental data shows that the reorientation motion of [N(C3H7)4]+ cations and/or [Cd2ClF5]2− anions is probably responsible for the observed conductivity.