Hydrothermal Synthesis, Crystal Structure, and Properties of A 3D Holmium(III) Coordination Framework Based on the Pyridine 2,6-dicarboxylate and Oxalate Ligands

A three dimensional holmium(III) coordination polymer formulated as [Ho 4 (pydc) 2 (μ 4 -C 2 O 4 ) 4 ·8H 2 O]·6H 2 O n (H 2 pydc = 2, 6-pyridine-dicarboxylic acid) has been synthesized via the reaction of 2,6-pyridine-dicarboxylic acid and ammonium oxalate with holmium nitrate, and characterized by elemental analysis, IR spectroscopy and X-ray single crystal diffraction. The complex presents 1D zigzag alternate chain array, and these 1D chains are further linked by oxalate ligand into 3D frameworks. Preliminary magnetic studies reveal the complex having weak but significant ferromagnetic couplings within the two adjacent magnetic centers bridged through oxalato, and the complex displays characteristic metal-centered fluorescence in solid state.