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Abstract: Three new metal pyridinecarboxylates, namely [Co2(pydc)2(H2O)5] (1), [Mn(pydc)(H2O)2] (2) and [Cd2(OH)2(2,4-pydc)] (3), were hydrothermally synthesized. X-ray single crystal structural analysis revealed: 1 and 2 have polymeric one-dimensional chain-like structure constructed by dinuclear cobalt units and Mn–O chains, respectively; 3 has a three-dimensional layer pillared structure constructed from inorganic Cd–O layer and pydc pillars. 1 shows antiferromagnetic interaction but 2 shows alternative antiferromagnetic and ferromagnetic interactions. [Copyright &y& Elsevier]

Three cluster-based coordination polymers, namely [Zn3(bpy)3(hip)2] · 5H2O (1), [Co3(bpy)3(hip)2] · 5H2O (2) and [Cd3(bpy)3(hip)2] (3) (bpy=2,2′-bipyridine, hip=4-hydroxyl-isophthalate) were synthesized and structurally characterized. X-ray single-crystal structural analyses revealed that both 1 and 2 crystallize in the chiral space group P21, while 3 crystallizes in the centric space group Pccn. Compounds 1 and 2 are isomorphous and both have (4,4) topological layered structures constructed from trinuclear metal clusters. Compound 3 also shows layered structure of (4,4) topology constructed from trinulear Cd(II) cores. The layers are stacked in a staggered ⋯ABAB⋯ fashion in 1 and 2 but in an overlapped ⋯AAA⋯ fashion in 3. There are two types of coordination modes of hip ligand in 1 and 2 but only one in 3. The structural difference between 1 (or 2) and 3 may be attributed to the difference of metal ion nature such as the ionic radius and coordination preference, resulting in the different orientation fashions of the auxiliary bpy ligands, stacking fashions of the layers, as well as chirality of the crystals. The chiral structures of 1 and 2 were also confirmed by measurements of powder second-harmonic-generation (SHG) measurements, which show that 1 and 2 have SHG intensity of 0.50 and 0.02 relative to that of urea, respectively. [Copyright &y& Elsevier]

Abstract: Hydrothermal reaction of Zn/Cd salts, NaN3 and 4-cyanobenzoic acid via in situ [2+3] cycloaddition generated two blue-green photoluminescent coordination polymers [Zn(cptta)(H2O)] (1) and [Cd(cptta)(H2O)] (2) (H2cptta=5-(4′-carboxy-phenyl)tetrazole). When only metal ions are considered as nodes, 1 shows rare 5-connected Shubnikov plane topological type and 2 has unprecedented 10-connected {312.424.59} topological type. [Copyright &y& Elsevier]

Abstract: Hydrothermal treatment of cobalt chloride, 2,2′-biimidazole (H2biim), oxalate acid and NaOH at 160°C for five days produced a three-dimensional mixed-valence metal-organic framework [CoIII(Hbiim)3]2[CoII 3(ox)3]·4H2O ( 1 ). Compound 1 exhibits a 3D network with tri-nodal (3-c)2(4-c)3 topology, in which [CoIII(Hbiim)3] building blocks as 3-connected nodes, and CoII ions as 4-connected nodes. The magnetic measurements reveal that compound 1 exhibits a spin canting antiferromagnetic coupling between adjacent CoII ions. [Copyright &y& Elsevier]

Abstract: Solvothermal treatment of silver nitrate, pyridine-4-thione (4-pdtH) and NH4SCN at 140°C for 3 days produced a three-dimensional metal–organic framework [Ag3(4-pdt)(SCN)2] (1) in which [Ag3S3] n tubes act as secondary building units and pyridine rings and CN groups act as linkers. At ambient temperature, 1 shows a blue emission band assigned as from a ligand-centred n→π∗ or π→π∗ process. [Copyright &y& Elsevier]