Research Article 
Two 2-D lanthanide coordination polymers constructed from hydroquinone-O,O'-diacetic acid
Xia Li, Yanqiu Li and Yanbing Zhang
Journal of Coordination Chemistry, 2008, 61(11), 1720-1729.
Abstract
Two new coordination polymers, 
Ln2(hqda)3(H2O)4·6H2O
n (H2hqda = hydroquinone-O,O'-diacetic acid, Ln = Dy, 1; Ho, 2), were prepared and characterized by elemental analysis, IR spectroscopy, TG-DTA, fluorescence spectroscopy, and single-crystal X-ray diffraction. The two complexes are isomorphous with similar crystal structures. In 1 and 2, each Ln(III) ion is nine coordinate with seven oxygen atoms from hqda ligands and two oxygen atoms from water molecules. Two adjacent Ln(III) ions are bridged by-COO- groups from hqda ligands in bidentate-bridging and chelating-bridging modes. These building blocks cross link through -OOCCH2OC6H4OCH2COO- spacers to form a 2-D network structure. The adjacent 2-D layers are further interlinked by hydrogen bonds to form a 3-D supermolecular structure.
ASCI-ID: 103-89