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

Five new heterometallic coordination polymers, {[LnCu(2)K(pydc)(4)(H2O)(9)]center dot H2O}(n) [Ln = La (1), Ln = Pr (2), H(2)pydc = pyridine-2,5-dicarboxylic acid], {[Ln(2)Cu(pydc)(4)(H2O)(8)]center dot 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.