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Abstract: The reactions of metal salts with pyrazine-2,3-dicarboxylic acid (H2pzdc), pyridine-2,5-dicarboxylic acid (H2pydc), pyrazine-2,3,5,6-tetracarboxylic acid (H4pztc), 4,4′-bipyridine (bipy) and 1,10-phenanthroline (phen) afforded four new ternary complexes, namely [Co2(pzdc)2(bipy)(H2O)2] n ·3nH2O (1), [Zn2(pzdc)2(bipy)(H2O)2] n ·3nH2O (2), [Co(pydc)2(H2O)2](H2bipy) (3) and [Cu2(pztc)(phen)2(H2O)2]·2HNO3·2H2O (4). The metal centers are all six-coordinated. Compounds 1 and 2 are 2D coordination polymers exhibiting wave-like polymeric networks. The 2D layers are stacked in an interpenetrating mode to form double-layered frameworks, which possess ∼8Å×6Å tunnels occupied by (H2O)6 clusters. Compound 3 is a mononuclear supramolecular compound in which 4,4′-bipyridine is protonated and acted as a cationic building block. Compound 4 is a centro-symmetric binuclear complex. Pztc4− as a hexadentate ligand coordinates to two Cu(II) ions to form four chelating rings. Phen are arranged in an ABAB parallel fashion to form a supramolecular architecture incorporating HNO3 lattice molecule. The thermal stabilities of 1−4 and luminescence of zinc complex 2 were also investigated. [Copyright &y& Elsevier]

Six Mn metal-organic frameworks have been synthesized under solvothermal conditions with V-shaped terphenyl tetracarboxylate ligands (H 4 ttac). Their structures were characterized by elemental analysis, infrared spectra, PXRD, thermogravimetric analysis, and single-crystal X-ray diffraction analysis. Crystal structures reveal that the coordination number of H 4 ttac ligand varies from 6 to 10, and each ligand links 4–8 Mn(II) ions. Coordination modes vary from η 6 μ 4 to η 10 μ 8 . The existence of DMF solvent can increase coordination number of the ligand. The first coordination saturated phthalate is presented. The variable-temperature magnetic studies indicate that complexes exhibit dominant antiferromagnetic behaviors. Structural parameters and coordination modes were summarized. The porosity of these complexes is less than 15%, indicating that the V-shape ligand is not a good choice to construct porous coordination polymers. [ABSTRACT FROM AUTHOR]

Abstract: Three new copper(II) azide coordination polymers with derivatives of 1,2,4-triazole as bridging coligands, namely [Cu2(admtrz)2(N3)4] n (1) (admtrz=4-amino-3,5-dimethyl-1,2,4-triazole), [Cu(4-abpt)(N3)2] n ·2nH2O (2) (4-abpt=4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole) and [Cu3(2-ptrz)2(N3)6] n (3) (2-ptrz=4-(2-pyridyl)-1,2,4-triazole), were prepared and characterized by elemental analyses, IR spectra and X-ray structural analyses. Compound 1 has a 1D chain structure in which Cu(II) ions are bridged by end-on (EO) azides and admtrz ligands. This compound contains three kinds of coordination modes for Cu(II) ions, including tetrahedral, square pyramidal and octahedral geometries. Compound 2 displays an interesting 3D framework structure, in which the azide ligands link Cu(II) ions in end-to-end (EE) mode affording a 2D square layer. This 2D layers are further bridged by bent 4-abpt ligands to form an interesting 3D framework. Furthermore, this structure also exhibits an alpha-Po net topology. Compound 3 displays a 1D rectangle-like chain structure linked by azides adopting end-on (EO) and end-to-end (EE) modes and 2-ptrz ligands. The IR and thermal stabilities of these coordination polymers 1–3 have also been studied. [Copyright &y& Elsevier]