SYNTHESIS AND CHARACTERIZATION OF LAYERED CHLOROCADMATES(II) WITH PEROVSKITE-LIKE STRUCTURES

The synthesis and the structural, thermal, and electrical characterization of tetrachlorocadmate(II) systems, with perovskite-like structures, are described. The countercations are diprotonated amines, such as the ethylenediamine and propane-1,3-diamine dications. The structural model of the compounds consists of layers extending to the ab plane of CdCl6 corner sharing octahedra. The holes between these layers are occupied by alkylammonium ions stabilizing the structure through hydrogen bonding. Thermal analysis shows the presence of a first-order phase transition in the propane-1,3-diammonium compound, related to the disordering of the hydrocarbon chains at high temperatures which causes a decrease in the c parameter and minor differences in the a and b parameters. The electrical conductivity of the investigated compounds is apparenly protonic and seems to increase as the distance between the layers containing the inorganic chains increases.