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Abstract: A new hexanuclear cadmium(II) complex of Cd6(pyim)4(Hpyim)6(sal)4 (Hpyim=2-pyridylbenzimidazole, H2sal=salicylic acid) (1) has been synthesized under hydrothermal condition and characterized by element analysis, FT-IR spectroscopy and luminescent analysis. X-ray crystallographic studies reveal that complex 1 displays a novel hexanuclear unit in which six cadmium ions are bridged by deprotonated salicylic and pyridylbenzimidazole ligands. In 1, the hexanuclear units are further assembled into a 3D supramolecular framework by hydrogen bonding, π–π and C−H⋯π stacking interactions. In the solid state, complex 1 shows blue photoluminescent property at room temperature. [Copyright &y& Elsevier]

Abstract: Four dimeric and polymeric coordination compounds [Zn2(bimb)2(pdc)2]·6H2O (1), [Cd2(bimb)2(tp)2]·H2O (2), [Cd(bimb)(ada)] (3) and [Co(bimb)(ada)] (4) (bimb, 4,4′-bis(imidazol-1-ylmethyl)biphenyl; pdc, pyridine-2,6-dicarboxylate; tp, terephthalate and ada, adipate) have been synthesized under hydrothermal conditions. Complex 1 is a discrete dinuclear metallomacrocycle featuring a 34-membered ring, in which the flexible bimb ligand acts as syn-conformation. While complexes 2–4 are 3D network structures connected by bimb and dicarboxylate ligands, the bimb ligand displays anti-confromation. [Copyright &y& Elsevier]

Abstract: A new cobalt(II) phosphonate, [enH2]0.5[Co(pa)(H2O)]·H2O (1) (H3pa=hydroxy-phosphono-acetic acid, HO2CCH(OH)PO3H2; en=ethylenediamine), has been hydrothermally synthesized and structurally characterized. Compound 1 has a honeycomb-like layer structure which is composed of CoO6 octahedra and μ3-pa ligands with the protonated en and lattice water molecules stabilized between the layers. Magnetic studies indicate that 1 shows weak ferromagnetic behavior, spin-glass behavior, and metamagnetic behavior. [Copyright &y& Elsevier]

cobalt(A novel three dimensional (3D) polymer, [Co2(hypa)2(4,4′-bipy)] (1) (H2hypa = hydroxy-phenyl-acetic acid, 4,4′-bipy = 4,4′-bipyridine), featuring pentacoordinate, dimeric cobalt(II) as subunits have been prepared, which shows low-dimensional antiferromagnetic ordering blow 15.2 K (TN). [ABSTRACT FROM AUTHOR]

A one-dimensional ribbon copper(II) complex, {CuII3(L)2(OH)2(NO3)2(H2O)4}n (1, HL=1-methyl-2-(3H-[1-3]triazol-4-yl)-1H-benzimidazole), has been hydrothermally synthesized from in situ generated HL at 160°C. Its structure is very unusual that all ligands and Cu(II) ion are distributed in the same horizontal plane in each chain. Two ligands chelate and bridge two Cu(II) ions to form a planar metalloligand which is then connected to each other through coordination to another Cu(II) to give the 2+1 infinite chain structure. Axial coordination sites of the Cu(II) are taken up by nitrate and water. Hydrogen bonding and π-π stacking interactions between chains intensify the stability of 3D supramolecular architecture. This particular structure is the result of a cooperative effect associated with the Jahn-Teller distortion of the copper(II) ion, the hydrogen bonding and π-π stacking interactions. Its magnetic properties indicate antiferromagnetic interactions between copper(II) within the chain. [ABSTRACT FROM AUTHOR]

A one-dimensional manganese(II) complex, [Mn( L 2 )] n ( 1 , HL = 4-pyridyl- NH -1,2,3-triazole), has been hydrothermally synthesized at 120 °C. In the structure of 1 , the Mn(II) ions are octahedral coordinated and further bridged by L − ligands, forming a rigid 1D ribbon coordination chain. Varieties of supramolecular interactions, such as hydrogen bonds and C H ⋯ π interactions, play an important role on the stabilization of the structures. As revealed by magnetic measurement, complex 1 displays weak antiferromagnetic interaction with θ = –4.83 K, the best fit using Fisher's 1D Heisenberg model gives the intrachain magnetic coupling constant J = –0.21 cm − 1 above 30 K due to the neighboring Mn(N–N) 2 Mn rings twisted in the angle of almost 90°. [ABSTRACT FROM AUTHOR]

Abstract: Hydrothermal treatment of a mixture of H3imdc (4,5-imidazoledicarboxylic acid), Na2SO4, Dy(NO3)3·6H2O and NaOH generated a novel inorganic–organic hybrid framework, {[Dy2(SO4)(Himdc)2(H2O)5]·H2O}n (1). Its crystal structure contains alternately arranged 1D left- and right-handed helical {Dy(Himdc)}n chains, each helical chain is composed of alternately arranged Dy(1) and Dy(2) ions connected by Himdc2– with bis(bidentate) linking mode. Every three helical chains are bridged by inorganic SO4 2− anions, which link Dy3+ ions in a tris(monodentate) mode to form a 3D framework. Compound 1 displays intense yellow photoluminescence corresponding to the characteristic 4F9/2 → 6HJ transitions of the Dy3+ ion. [Copyright &y& Elsevier]

Abstract: One novel 1D chain of {[Zn2(L)3(H2O)(NO3)]·2.5H2O} n (HL =1-methyl-2-(3H-[1, 2, 3]triazol-4-yl)-1H-benzoimidazole) has been hydrothermally constructed from in situ generated 1-methyl-2-(3H-[1, 2, 3]triazol-4-yl)-1H-benzoimidazole ligand at 160°C. Compound 1 exhibits a 1D butterfly-like chain architecture, which is further assembled into a 3D supermolecular network by interchain hydrogen bonds. TGA studies show that compound 1 is highly thermally stable. The fluorescent property in the solid state is also explored, and the emission spectrum shows a blue shift of 62nm compared with that of HL, which may be assigned to ligand-to-metal charge transfer. [Copyright &y& Elsevier]

A cadmium (II) coordination polymer, namely {[Cd5(Ln)6Cl4]·2H2O}n (1, HLn =1-methyl-2-(3H-[1–3]triazol-4-yl)-1H-benzoimidazole), has been constructed from in situ generated HLn under hydrothermal condition. The unsuccessful synthesis of 1 under similar synthesis condition using HLn as reactant suggests the in situ reaction is crucial for the assembly of the compound. Crystallography study reveals that 1 processes layer structure in which chains of [Cd3(Ln)4Cl4]2− were connected by a pair of Cd ions. These layers further stack in an AAA model to form a 3D supramolecular framework and hydrogen bonding as well as π–π interaction were formed between adjacent layers to stabilize the framework. TGA indicates that 1 is highly thermally stable up to about 380°C. The luminescence of 1 in the solid state which may be assigned to intraligand transition shows a blue shift of 16nm compared to that of HLn·HCl. [ABSTRACT FROM AUTHOR]