Crystal structure, optical and electrical properties of metal-halide compound [C7H16N2] [ZnCl4]

A new organic-inorganic hybrid compound [C7H16N2][ZnCl4] was synthesized by hydrothermal method and characterized by single-crystal X-ray diffraction, IR and Raman spectroscopy, optical absorption, differential scanning calorimetry and dielectric measurements. Single crystal diffraction results showed that [C7H16N2][ZnCl4] crystallizes in the monoclinic system, space group P2(1)/c at room temperature. In the molecular arrangement, the tetrachlorozincate anions are connected to organic cations through N-H - Cl hydrogen bonds. The Raman and IR analyses confirm the presence of the organic groups and the anionic entities. UV-Visible absorption spectrum revealed the energy of the optical band gap. DSC measurements indicated that [C7H16N2][ZnCl4] undergoes three sequential phase transitions at 287, 338 and 356 K. The dielectric study proved the ferroelectric properties below the 338K and indicates their classical character for this compound. The analysis of Nyquist plots revealed the contribution of the bulk mechanism and the grain boundaries.