Optical, UV-Vis spectroscopy studies, electrical and dielectric properties of transition metal-based of the novel organic-inorganic hybrid (C6H10N2)(Hg2Cl5)2.3H2O

In this work, we are interested in the synthesis of new hybrid material (C₆H10N₂)(Hg₂Cl5)2.3H₂O grown by hydrothermal methods. X-ray diffraction indicates that this compound crystallizes at 150(2) K in the monoclinic system with C2/c space group, with the following unit cell parameters: a=19.6830(15) Å, b=18.1870(15) Å, c=6.8567(6) Å, β=93.224(3)∘ and Z=4. On the other hand, the optical properties of this compound were studied using ultraviolet-visible (UV-Vis) spectroscopy in the range 200-800nm. Furthermore, the optical absorbances are used to determine the absorption coefficient α and the optical band gap Eg, so the Tauc model was used to determine the optical gap energy of the compound (C₆H10N₂)(Hg₂Cl5)2.3H₂O. The analysis of the results revealed the existence of optical allowed indirect transition mechanisms with the band gap energy equal to (2.37eV) for liquid and (4.33eV) for solid. Impedance measurements indicate that the electrical and dielectric properties are strongly dependent on both temperature and frequency. Nyquist plots (Z‧‧ versus Z‧) show that the conductivity behavior is accurately represented by an equivalent circuit model which consists of a series combination of bulk and grain boundary. Furthermore, the angular frequency dependence plots of the real and imaginary parts, ɛ‧ and ɛ‧‧, of complex dielectric permittivity ɛ∗ and tan δ losses at several temperatures between 303 and 453K were studied for the title compound. Finally, the modulus plots can be characterized by the presence of two relaxation peaks.