STRUCTURE OF COPPER(II) TEREPHTHALATE TRIHYDRATE

Cu[Cu6H4(COO)2].3H2O, M(r) = 281.71, orthorhombic, Pbcn, a = 6.869 (3), b = 22.985 (11), c = 6.298 (3) angstrom, V = 994.4 (14) angstrom 3, Z = 4, D(x) = 1.88 Mg m-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 2.22 mm-1, F(000) = 572, room temperature, R = 0.036 for 812 unique reflections having \F\ > 4-sigma(\F\). The Cu atoms are coordinated by two carboxylate O atoms and four water-molecule O atoms in a significantly distorted octahedral arrangement. There are three different coordination Cu-O distances: two of 1.925 (2) angstrom with the two carboxylate O atoms, two of 1.981 (2) angstrom and the largest two of 2.479 (2) angstrom. The octahedra share common edges with octahedra of two neighbouring Cu atoms to form zigzag chains in the c direction. The chains are linked by hydrogen bonds and in addition the resulting layers are held together via hydrogen bridges building a three-dimensional network.