New 3d-4f heterometallic coordination polymers based on pyrazole-bridged Cu^IILn^III dinuclear units and sulfate anions: Syntheses, structures, and magnetic properties

A series of 3d-4f heterometallic coordination polymers ([CuLn ₂(PdC)₂(SO₄)(H₂O) ₆]·H₂O)_n (Ln = Tb (1), Dy (2); H ₃pdc = 3,5-pyrazoledicarboxylic acid), ([CuLn₂(PdC) ₂(SO₄)(H₂O)₄]·H ₂O)_n (Ln = Sm (3), Eu (4), Gd (5), Tb (6), Dy (7)) have been hydrothermally synthesized and structurally characterized. The sulfate anions were in situ obtained from oxidation of CuSCN during the reaction. Complexes 1-7 are all constructed from pyrazole-bridged Cu^IILn _III dinuclear units and sulfate anions. Complexes 1 and 2 are isostructural and possess an infinite double-stranded tapelike ID coordination framework. However, complexes 3-7 are interesting 3d-4f heterometallic coordination polymers with similar 3D framework structures. The magnetic properties of compounds 2, 4-6 have been investigated through the magnetic measurements over the temperature range of 1.8-300 K.