Synthesis, Structure and Thermal Behavior of a New Coordination Polymer Based on Mixed Pyrazine-2-carboxylate and Oxalate Ligands

A new 4d-4f coordination polymer, [AgGd(pyzc)(2)(ox)center dot H2O)] (1) [pyzc = Pyrazine-2-carboxylate, ox = oxalate] has been successfully synthesized under hydrothermal conditions and structurally determined by single-crystal X-ray diffraction, and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and power X-ray diffraction. Single-crystal X-ray analysis reveals that it crystallizes in the monoclinic space group P2 (1) /c with a = 10.0746(1) , b = 18.642(1) , c = 8.0525(2) , beta = 112.470(1)A degrees, Mr = 617.34, Z = 4, V = 1505.6(2) (3), mu = 5.732, F(000) = 1164. The Gd(III) ion is nine-coordinated by two O-donors and two N-donors of two different chelating pyzc ligands, four O-donors of two different chelating oxalate ligands, and one O-donor of another carboxylate group of one pyzc ligand. The compound represents a 3D microporous polymeric network constructed by gadolinium-oxalate chains and Ag-pyzc subunits.