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Abstract: Two novel Zn(II) coordination polymers, [Zn5(pytpy)8(fum)4(H2O)4(OH)2] n · n(CH3OH)·2n(H2O) (1) and [Zn3(pytpy)4 (btc)2] n ·2n(H2O) (2) (pytpy=4′-(4-pyridyl)-3,2′:6′,3″-terpyridine, H2fum=fumaric acid, H3btc=1,3,5-benzenetricarboxylic acid) have been hydrothermally synthesized and structurally characterized. Complex 1 is a 2D layer structure, which is constructed from linear pentanuclear Zn(II) subunits interconnected via bidentate-bridging pytpy ligands and tridentate-bridging fum2− anions. Complex 2 is a 3D network structure, μ2-pytpy ligands link the layers based on the heart-like hexanuclear subunits to form the 3D network. Both complexes show strong fluorescence emission upon excitation at 310nm in solid state. Additionally, these two complexes possess great thermal stabilities, especially for 2, the framework is stable up to 350°C. [Copyright &y& Elsevier]

Abstract: Two novel cadmium(II) coordination polymers [Cd(pyip)(ox)]·H2O (1) and [Cd2(pyip)2(ox)2·(H2O)][Cd(pyip)(ox)]·4(H2O) (2) (pyip=2-(pyridin-3-yl-1H-imidazo [4,5-f][1,10]phenanthroline, H2ox=oxalic acid), have been hydrothermal synthesized and characterized by single crystal X-ray diffraction. Compound 1 is 1D zigzag chain, in which oxalate anion as bridging ligand is responsible for the formation of the main framework and pyip as chelating ligand grafts on two sides of the zigzag chain. Compound 2 contains two kinds of independent polymers [Cd2(pyip)2(ox)2(H2O)] (A) and [Cd(pyip)(ox)] (B) to form an interdigitated 1D+1D structure, in which polymers A and B are paratactically assembled in an ABCD sequence. The fundamental unit of polymer B in 2 is the same as that in 1. For compounds 1–2, weak interactions, primarily hydrogen bonding and π⋯π stacking interactions, have greatly influence on the supramolecular motifs recognized in the crystal packing. Especially, the oxalate anions as bridging ligand simultaneously adopt multiform coordination modes in two compounds. In addition, 1 and 2 displayed a strong fluorescent emission in the solid state at room temperature. [Copyright &y& Elsevier]