An anion-directed unprecedent three-dimensional array with erbium(III) based on the 2,6-pyridinedicarboxylate

Reaction of 2,6-pyridine-dicarboxylic acid and ammonium oxalate with erbium salt results in the formation of a self-assembly network based upon mixed ligands of oxalate and pyridine-dicarboxylate formulated as {[Er4(pydc)2(μ4-C2O4)4]·8H2O·6H2O}n (H2pydc = 2,6-pyridine-dicarboxylic acid), in which supramolecular left-handed and right-handed helices are connected via μ4-oxalate anions, and gave the 1D coordination channels constructed via bridging oxalate and pydc ligands. The complex also displayed photo-luminescent properties in the solid state at room temperature.