Structural, Thermal, and Electrical Characterization of Bis(ethylethylene)diammonium Dichloride Tetrachlorocadmate(II) with Perovskite-like Structure

The synthesis, thermal and electrical characterization of a chlorocadmate(II) system with perovskite-like structure of formula (etenH-2)2[CdCl4].Cl2 (etenH-2 = ethylethylenediamine dication) are described. The compound crystallizes in space group P2(1)/c. The unit-cell dimensions are a = 19.214(1) angstrom, b = 7.301(1) angstrom, c = 7.227(3) angstrom, beta = 100.23(1)-degrees, V = 997.7(4) angstrom3, Z = 2. The final R value is 0.0486 (R(w) = 0.0497). The crystal structure consists of inorganic layers of (CdCl6) corner-sharing octahedra, organic dications intercalated between them and uncoordinated chloride ions. Only one end of the organic dications interact via hydrogen bonds with the inorganic layers, with the second end involved in hydrogen bonds with the free chloride ions. Furthermore a network of hydrogen bond interactions among the inorganic layers, the organic dications, and the uncoordinated chlorine atoms contribute to the crystal packing. The compound, thermally stable up to the melting point, behaves as an electrical insulator at low temperatures, approaching semiconductor values at higher ones.