Two 3D Zinc(II) coordination frameworks constructed from pyrazine-2,3-dicarboxylate and 1,2-bis(4-pyridyl)ethylene

Two 3D coordination polymers, {[Zn(μ3-pzdc)(μ-dpeten)0.5]∙3H2O}n (1) and [Zn(μ3-pzdc)(μ-dpeten)0.5]n (2) (H2pzdc = pyrazine-2,3-dicarboxylic acid and dpeten = 1,2-bis(4-pyridyl)ethylene) have been synthesized by hydrothermal methods and structurally characterized by elemental analysis, IR spectroscopy, single-crystal and powder X-ray diffraction. In complex 1, each pzdc ligand bridges three Zn(II) ions through forming two-dimensional layers. The adjacent 2D layers are further connected by dpeten ligand to generate a novel 3D framework containing one-dimensional large porous channel. It displays a 5-connected bnn hexagonal topology with point symbol {46.64}. Although the complex 2 was obtained under the same reaction conditions together with complex 1, it exhibits 3D→3D a 2-fold interpenetration network with 6-connected pcu α-Po primitive cubic topology with point symbol {412.63}. The adjacent three Zn(II) ions are linked by tridentate bridging pzdc ligands to form a 2D layer structure. The 2D layers are further bridged by dpeten ligand to form a 3D pillar-layered network. Moreover, thermal and photoluminescent properties of complexes 1 and 2 have also been studied.