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The employment of the new Schiff base ligand 2‐[(4‐chloro‐2‐hydroxybenzylideneamino)methyl]phenol (H2L) bearing O2N donors for the preparation of a novel Co6 cluster is reported. The hexanuclear cobalt complex, namely, di‐μ2‐acetatotetrakis{μ2‐2‐[(4‐chloro‐2‐oxidobenzylideneamino)methyl]phenolato}tetra‐μ3‐methanolato‐tetracobalt(II)dicobalt(III), [CoII4CoIII2(C14H10ClNO2)4(CH3COO)2(CH3O)4], was obtained using Co(CH3COO)2·4H2O and H2L as starting materials in MeOH under solvothermal conditions. The six metal ions are linked together by the μ3‐O atoms of four deprotonated MeOH molecules, two CH3COO− units and six phenolate O atoms of four L2− ligands to form a defect disk‐shaped topology. DC magnetic susceptibility investigations revealed the existence of antiferromagnetic interactions in the Co6 cluster. [ABSTRACT FROM AUTHOR]

Abstract: Three novel d10 metal coordination polymers, {[Cd(H2odpa)(phen)2]·H2O} n (1), [Cd2(odpa)(phen)(H2O)2] n (2), {[Zn4(odpa)2(phen)2(H2O)2]·H2O} n (3), (H4odpa=4,4′-oxydiphthalic acid, phen=1,10-phenanthroline) were obtained with different metal/ligand ratios through hydrothermal method and characterized. Compound 1 forms a one dimensional zigzag chain, in which two phen ligands chelate to one cadmium atom. Compound 2 shows a three dimensional network structure comprised of new tetranuclear cadmium clusters as the nodes and (odpa)4− anions as the linkers, exhibits an unusual topological structure. Compound 3 is an unprecedented three dimensional polymer based on octanuclear zinc clusters cross-linked by (odpa)4− anions. In 1–3, central CdII/ZnII ions and (odpa)4− ligand display completely different coordination modes and conformations. In addition, the thermal stabilities and photoluminescence properties of 1–3 were also studied. [Copyright &y& Elsevier]

A silver(I) coordination polymer, [Ag2(bpdc)]n (1) (H2bpdc = 2,2'-bipyridyl-3,3'-dicarboxylic acid), has been synthesized and characterized. Compound 1 exhibits a 2-D network containing 1-D channels. Each (bpdc)2- is an octadentate μ6-1igand coordinating with six Ag(I)'s in 1. This coordination of (bpdc)2- ligand is first observed here. Neighboring networks are arranged in a [ABAB···] pattern to form 3-D supramolecular architecture by π···π stacking. Compound 1 shows intense photoluminescence at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: To determine the influence of metal ion and the auxiliary ligand on the formation of metal–organic frameworks, six new coordination polymers, {[Mn2(bpdc)(bpy)3(H2O)2]·2ClO4 ·H2O} n (1), {[Mn(bpdc)(dpe)]·CH3OH·2H2O} n (2), {[Cu(bpdc)(H2O)2]} n (3), {[Zn(bpdc)(H2O)2]} n (4), {[Cd(bpdc)(H2O)3]·2H2O} n (5), and {[Co(bpdc)(H2O)3]·0.5dpe·H2O} n (6) (H2bpdc=2,2′-bipyridine-3,3′-dicarboxylic acid, bpy=2,2′-bipyridine, dpe=1,2-di(4-pyridyl) ethylene), have been synthesized and characterized. Compound 1 forms 1D helical chain structure containing two unique MnII ions. In 2, the bridging ligand dpe links Mn-bpdc double zigzag chains to generate a layer possesses rectangular cavities. In 3, bpdc2− ligand connects to three metal centers forming a 2D network. Different from the above compounds, 4 displays a 1D double-wavelike chain. Compound 5 features a helical chain. Compound 6 also displays a helical chain with guest molecule dpe existing in the structure. These diverse structures illustrate rational adjustment of metal ions and the second ligand is a good method for the further design of helical compounds with novel structures and properties. In addition, the magnetic properties of 2, 3 and 6, the thermal stabilities and photoluminescence properties of 4 and 5 were also studied. [Copyright &y& Elsevier]

Abstract: Four new mixed-ligand complexes, namely [Zn2(pam)2(2,2′-bpy)2] (1), [Cd(pam)(2,2′-bpy)2] n (2), [Zn(pam)(phen)] n (3) and [Cd (pam)(phen)] n ·0.5n CH3CH2OH·0.5nH2O (4) (H2pam=pamoic acid, 2,2′-bpy=2,2′-bipyridine, phen=1,10-phenanthroline) have been synthesized under hydro(solvo)thermal conditions. Complex 1 possesses a discrete dinuclear metallamacrocyclic structure. Complex 2 is a 1D homochiral helical coordination polymer that is built from achiral components, whereas 3 displays a 1D helical chain structure. 4 is an unusual 2D double-layered structure generated by π⋯π interactions of two 2D networks. The structural differences of these complexes are mainly due to the differences of the size of the rigid aromatic chelate ligands and d10 metal ions. It appears that the chelate ligands and metal ions of the larger size favor the formation of high-dimensional structures, whereas those of the smaller size favor the formation of low-dimensional structures in the present system. The photoluminescence and thermal stability of these complexes were investigated. [Copyright &y& Elsevier]