A novel praseodymium coordination polymer with Pcu topology: Crystal structure, thermal decomposition, luminescence and magnetic properties

A unique lanthanide coordination polymer, formulated as {[Pr3(Heimda)2(μ2-HCOO) (μ2-C2O4)2·5H2O]}n (H3eimda = 2-ethyl-1H‐imidazole‐4,5‐dicarboxylic acid, H2C2O4 = oxalic acid) (1), has been hydrothermally synthesized by using lanthanide(III) nitrate, H3eimda acid at the presence of two kinds of carboxylate as coligands. The polymer was characterized by elements analysis, IR spectroscopy, thermogravimetry, variable-temperature magnetic susceptibility and single‐crystal X-ray diffraction study. Polymer 1 possesses three-dimensional (3-D) framework with Pcu topology, containing the original 1D zig-zag chain composed of [Pr-HCOO]2+ moieties. Variable temperature magnetic susceptibility measurements indicate that depopulation of the Stark levels or possible antiferromagnetic interactions within polymer 1 leads to the continuous decrease of χMT when the samples are cooled from 300 to 2 K, and the photoluminescence properties of polymer 1 were also investigated.