Hydrothermal synthesis of 3D porous architectures

A novel porous lanthanide-organic coordination polymer, [Nd(H2O)(HnicO)(TP)center dot 2H(2)O (1) (H(2)nicO=2-hydroxynicotinic acid, TP= terephthalate), was prepared under hydrothermal condition and characterized by single-crystal X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Compound 1 exhibited a flexible coordination geometry of lanthanide ions, which possessed a three-dimensional (3D) open framework with one-dimensional (1D) channels containing lattice water molecules. This framework structure exhibited a high stability up to 330 degrees C after removing free water molecules. A homometallic supramolecular framework (Zn(HniCO)(2)(H2O)(2) (2)) was obtained due to the competitive reaction between organic ligands, Nd3+ and Zn2+ ions. The results showed that on the basis of the soft-hard/acid-base principle the coordination selection between metal ions and organic ligands played an essential role in the smart construction of lanthanide architectures.