Characterization and Electrical Properties of [C6H9N2]2CuCl4 Compound

We report measurements of X-ray powder diffraction, vibrational study, the differential scanning calorimetry (DSC), and the electric properties of a made-up [C6H9N2]2CuCl4 sample. The alternative current (ac) conductivity of the compound [C6H9N2]2CuCl4 has been measured in the temperature range 356–398？K and the frequency range 209？Hz–5？MHz. The Cole-Cole (the imaginer part ( ) versus real part ( ) of impedance complex) plots are well fitted to an equivalent circuit model which consists of a parallel combination of a bulk resistance ( ) and constant phase elements (CPE). The single semicircle indicates only one primary mechanism for the electrical conduction within [C6H9N2]2CuCl4. The variation of the value of these elements with temperatures confirmed the result detected by DSC and dielectric measurements. Thus the conduction in the material is probably due to a hopping or a small polaron tunneling process. 1. Introduction Organic-inorganic hybrid compounds can be designed to utilize synergistic interactions between the dissimilar components, which can yield new properties and/or an enhanced performance. Indeed, synergy will be critical in achieving targeted physical properties (e.g., electronic, optical and transport properties). Thus, organic-inorganic hybrid materials combine the advantageous properties characteristic of inorganic solids (e.g., high carrier mobilities, thermal stability) with those of organic molecules (e.g., ease of processing, high fluorescence efficiency, and large polarizability) [1–11]. A novel group of crystals, containing heteroaromatic cations like, pyridinium, substituted pyridinium, and imidazolium ones, have been recently synthesized and characterized [11–13]. Since aromatic heterocyclic cations are bestowed a significant electric dipole moment; thus some halogenoantimonates(III) and halogenobismuthates(III) containing these cations form strongly polar structures. Inorganic component can introduce some special structural units, such as distorted tetrahedron and octahedron. In an attempt to study the electric behavior in this class of compounds we have successfully synthesized a compound of formula bis(2-amino-4-methylpyridinium) tetrachloridocuprate(II) ([C6H9N2]2[CuCl4]). At room temperature, the synthesized compound crystallizes in the monoclinic system (C2/c space group) with and the following unit cell dimensions: (3) ？, (3) ？, (4) ？, and (17)° [11]. The crystal structure contains chains of cations alternating with stacks of tetrahedra anions of tetrachloridocuprate (Figure 1(a)). Both N–H？Cl and π-π stacking