Synthesis, structural characterization and electrical conduction mechanism of the new organic–inorganic complex: ([(C3H7)4N]FeCl4)

A new organic–inorganic hybrid material, tetrapropylammonium tetrachloferrate, has been synthesized and characterized by single-crystal X-ray diffraction, thermal analysis, vibrational and impedance spectroscopies. The single crystals were obtained by slow evaporation of an aqueous solution of the reactants at room temperature. The [(C₃H₇)₄N]FeCl₄ compound crystallizes in the orthorhombic system (Pbca space group). The structural analysis shows the presence of cavities arranged in the [100] direction. It is formed by six cations ([(C₃H₇)₄N]⁺) which accommodate the anionic group ([FeCl₄]⁻). The differential scanning calorimetry (DSC) indicates the presence of three phase transitions, located at T = 333, 368 and 398 K. Besides, the impedance spectra were explored with an equivalent circuit including a parallel combination of resistance and fractal capability. From Jonscher's power law, the Correlation Barrier Hopping (CBH) and the Non-overlapping Small Polaron Tunneling (NSPT) model prevailed the conduction mechanism in the title compound. Furthermore, the electrical modulus analysis shows the non-Debye type conductivity relaxation.