A series of three-dimensional rare earth coordination polymers with two binary carboxylate as mixed-ligand:: Syntheses, structures, properties of [LnIII(mal)(ox)0.5(H2O)2]•2H2O (Ln = Pr, Nd, and La)

A series of lanthanide coordination polymers, [Ln(III)(mal)(ox)(0.5)(H2O)(2)] center dot 2H(2)O (Ln = Pr (1), Nd (2), and La (3); H(2)mal= maleic acid; H(2)ox = oxalic acid), were synthesized firstly by the reaction of Ln(III) nitrate salts with maleic anhydrid and oxalie acid under hydrothermal conditions and were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction, X-ray diffraction analyses reveal that they are crystallized in orthorhombic space group Fddd.. Lanthanide metal center atom (Ln) and its corresponding centrosymmtric atom link through two chelating/bridging bidentate carboxyl groups of inaleic acid ligands to form an infinite inorganic rod-shaped building unit. These rodshaped building units were linked to each other through the carbon atoms of the maleate anions on the [110] plane to form lanthanidemaleic acid layers. The oxalic acid pillared lanthanide-maleic acid layers with intersected channels by free water Molecules Consist of a 3D framework structure. The thermogravimetric analyses of 1-3 were discussed in detail. The courses of the thermal decomposition of complexes are similar.