Synthesis, Crystal Structures, and Properties of Novel Heterometallic La/Pr−Cu−K and Sm/Eu/Tb−Cu Coordination Polymers

Five new heterometallic coordination polymers, {[LnCu2K(pydc)4(H2O)9]·H2O}n [Ln = La (1), Ln = Pr (2), H2pydc = pyridine-2,5-dicarboxylic acid], {[Ln2Cu(pydc)4(H2O)8]·H2O}n [Ln = Sm (3), Ln = Eu (4), Ln = Tb (5)], have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structural analysis revealed that complexes 1 and 2 are the first Ln/Cu/K structures containing Cu(II) sandwiched in the interlayer regions of the two La/K planes alternately arranged along the b-axis. In complexes 3−5, two distinct types of building blocks, Ln(pydc)(H2O)4 and Cu(pydc)2, are linked together by pydc ligands to form a two-dimensional net structure. The magnetic properties of 1 and 2 and the luminescence properties of 3−5 have been investigated.