POLYNUCLEAR CHLOROCADMATE(II) COMPOUNDS WITH RIBBON-LIKE STRUCTURES -SYNTHESIS, STRUCTURAL CHARACTERIZATION AND THERMAL-BEHAVIOR

In this paper we report the synthesis and the structural characterizat ion of two polynuclear chlorocadmate(II) systems with ribbon-like stru cture of formula (H(2)eten)[Cd2Cl6] . H2O (H(2)eten = ethylethylenedia mine dication) and (Hetpipd)(2)[Cd5Cl12(H2O)(2)] . H2O (Hetpipd = 1-et hylpiperidine cation), respectively. (H(2)eten)[Cd2Cl6] . H2O crystall izes in space group P2(1)/a. The unit cell dimensions are a = 16.910(2 ), b = 13.570(2), c = 6.701(3) Angstrom, beta = 94.93(2)degrees, V = 1 532(1) Angstrom(3), Z = 4. The final R value is 0.029 (R(w) = 0.028). Its structure consists of organic dications, polymeric ribbons formed by two infinite zig-zag chains running along the z axis linked by a co mmon edge between adjacent octahedra and uncoordinated water molecules . The (Hetpipd)(2)[Cd5Cl12(H2O)(2)] . H2O crystallizes in space group C2/c. The unit cell dimensions are a = 26.811(2), b = 6.643(3), c = 21 .724(2) Angstrom, beta = 111.25(3)degrees, V = 3606(2) Angstrom(3), Z = 4. The final R value is 0.039 (R(w) = 0.045). Its structure consists of alternate trinuclear [Cd3Cl6(H2O)(2)] and dinuclear [Cd2Cl6](2-) u nits, forming polymeric ribbons, organic cations and uncoordinated wat er molecules. Both packings are strengthened by hydrogen-bond interact ions between anions and cations. The thermal properties for both compo unds are discussed.