Structural characterization of lanthanide coordination polymers assembled from V-shaped 4,4′-oxybis(benzoate) ligand

Hydrothermal reaction of lanthanide(III) (Nd, Er and Tm) chloride with sodium salt of 4,4'-oxybis(benzoic) acid (H(2)oba) leads to the formation of two types of monocrystals: prismatic[Nd(Er)(Hoba)(oba)(H2O)(2)]center dot 0.8H(2)O (1, 2) and plate-shaped [Tm(2)oba(3)(H2O)(4)]center dot 1.38H(2)O (3) for which single-crystal X-ray measurements were performed. Isomorphous compounds 1 and 2 consist of eight-coordinated lanthanide ions bonded with oba, Hoba and aqua ligands into the 2D layers. In the structure 3 two types of Tm(III) centers are bridged by oba linkers into 2D layer architecture. Uncoordinated water molecules are located within the cavities between layers. Furthermore, the ATR-IR spectra of isolated monocrystals and thermal behaviours of the compounds are discussed. (C) 2011 Elsevier B.V. All rights reserved.