AN UNUSUAL HYDROGEN-BONDED NETWORK ASSOCIATED WITH METAL-ORGANIC CHAINS - STRUCTURE AND CRYSTAL PACKING OF THE COORDINATION POLYMER [CD(TEREPHTHALATE)(H2O)(3)]CENTER-DOT-4H(2)O

Single crystals of [Cd(terephthalate) (H2O)(3)].4H(2)O (1), triaquo(1, 4-benzenecarboxylato-kappa O)cadmium tetrahydrate, are grown in a sili ca gel column. Crystal structure analysis shows that (1) is a polymer with metal-organic chains stacked along the a axis forming layers para llel to the ab plane. These layers are linked by an unusual hydrogen-b onded network formed by the water molecules (both 'free' and coordinat ed ones) and the carboxylate O atoms. This network comprises tridymite -like O-8 cages which 'propagate' in the direction of the a axis, mimi cking the way they 'propagate' along the c axis in hexagonal ice.