New 3d−4f Heterometallic Coordination Polymers Based on Pyrazole-Bridged CuIILnIII Dinuclear Units and Sulfate Anions: Syntheses, Structures, and Magnetic Properties

A series of 3d−4f heterometallic coordination polymers {[CuLn 2 (pdc) 2 (SO 4 )(H 2 O) 6 ]·H 2 O} n (Ln = Tb ( 1 ), Dy ( 2 ); H 3 pdc = 3,5-pyrazoledicarboxylic acid), {[CuLn 2 (pdc) 2 (SO 4 )(H 2 O) 4 ]·H 2 O} 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 II Ln III dinuclear units and sulfate anions. Complexes 1 and 2 are isostructural and possess an infinite double-stranded tapelike 1D 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.