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Reactions of a bis-pyridyl-bis-amide ligand, N,N′-bis(pyridin-3-yl)-2,6-pyridinedicarboxamide (bppdca) with nickel(II) and cobalt(II) salts resulted in a tetragonal molecular cage, [Ni2(bppdca)4(SCN)4] (1), and a 1-D polymeric macrocyclic complex, [Co(bppdca)(SO4)(CH3OH)(DMF)] n ·nCH3OH (2) (DMF = N,N′-dimethylformamide). Compound 1 features a tetragonal cage-like structure. In each cage, four bppdca ligands are twisted in the same direction, which endow the cage with chirality. However, because the twist or screw directions of adjacent cages are contrary, 1 is a mesomer and exhibits no chirality on the whole. Compound 2 possesses a 1-D, double-chain structure containing Co4(SO4)4(bppdca)2 macrocyclic subunits. [ABSTRACT FROM PUBLISHER]

Abstract: Six new 1–3D coordination polymers of an unsymmetrical angular ligand 3-pyridin-4-ylbenzoate (L), namely, [Ni(L)2(C2H6O2)] n (1), [Cd(L)2(H2O)2] n ·4H2O (2), [Zn2(OH)(L)3] n (3), [Fe2(OH)(L)3] n (4), [Ni(L)2(H2O)] n (5) and [Cd(L)2(H2O)] n (6) were hydro(solvo)thermally synthesized. They have abounding structure chemistry ranging from one-dimensional ribbons (1 and 2), and two-dimensional novel helical double-layered frameworks (3 and 4) to three-dimensional CdSO4-topological porous interpenetrating architectures with hydrophilic and hydrophobic channels regularly arraying (5 and 6). The labile conformations and coordination modes of ligand L, which were finely tuned by reaction conditions, perhaps play the key role in the construction of various architectures. Very interestingly, the slight difference in solvent system or temperature resulted in the distinct architectures of nickel(II) complexes 1 and 5 or cadmium(II) complexes 2 and 6. As expected, the unsymmetrical ligand L has a trend to construct metal-organic helixes as observed in 3 and 4. Thermogravimetric analysis of 5 shows the main framework retains stability until a higher temperature 379°C. The 3D microporous network of 5 can slightly absorb for N2 and Ar. Compounds 2, 3 and 6 emit ligand-centered photoluminescence but with obviously different intensities owing to the structural diversities and coordinating water molecules. [Copyright &y& Elsevier]

U-shaped tripyridyl ligand 2,6-bis(pyridine-4-carboxamido)pyridine (L) was synthesized and used to assemble metal complexes. The resulting new complexes [Mn(L)3(SCN)2]n (1) and [Co(L)3(SCN)2]n (2) are isostructural, crystallizing in the monoclinic C2/c space group. In compounds 1 and 2, each metal is in a slightly distorted octahedron ligated by six nitrogens from four L and two SCN-. Complexes 1 and 2 possess infinite 1-D zigzag polymeric chain structures where L adopts bridge and terminal coordination. These 1-D coordination polymers assemble into 3-D supermolecules of compounds 1 and 2 through hydrogen bonds. Fluorescence measurements and thermal analysis show that 1 emits strong fluorescence with a single broad band centered at 410 nm upon excitation at 357 nm and the polymeric chain structure is stable up to 340°C. [ABSTRACT FROM AUTHOR]

Abstract: Three new coordination polymers based on IB metal thiocyanates, [CuII(NCS)2(DMSO)4(meso-dpb)] n (1), (2), [CuI(NCS)(pia)] n (3) (dpb=2,3-di(4-pyridyl)-2,3-butanediol, bpp=1,3-bis(4-pyridyl)propane, pia= N,N′-(1,2-phenylene)diisonicotinamide), have been synthesized by the pre-assembly method and characterized by X-ray crystallography. In 1, CuII cations are bridged by meso-dpb ligands to form a one-dimensional (1D) linear chain. Compound 2 consists of 2D undulated layers of (4, 4) topology that show twofold parallel interpenetration. In the case of 3, the MI center adopts tetrahedral coordination geometry and the 2D networks are formed by organic ligand with “folding ruler-shaped” NCS−–M chains. The thermal properties of 1–3 were also investigated. [Copyright &y& Elsevier]

Abstract: Self-assembly of 1,2-bis(3-pyridylcarboxylamide)benzene (H2bpb) with sulfate salts gave rise to three new coordination polymers, [Ni2(H2bpb)2(H2O)2(CH3OH)2(SO4)2] n · nCH3OH 1, [Co2(H2bpb)2(CH3OH)2(DMF)2(SO4)2] n ·0.5nH2O 2 (DMF= N,N′-dimethylformamide) and [Zn2(H2bpb)2(CH3OH)2(DMF)2(SO4)2] n ·0.5nH2O 3. They all crystallize in a monoclinic space group C2/c, with two crystallographically distinct metal nodes being surrounded by slightly distorted octahedra. There is a homologous chair-like unit with bridging ligand H2bpb as the back and bis(monodentate) sulfate anion as the seat in their crystal structures. Through the recognition of strong π⋯π stacking interactions between benzene rings, those chains formed by the unlimited extension of the chair-like units stack up to produce 1-D channels along c axis where lattice molecules and terminal ligands are accommodated. Interestingly, the trans,trans,syn achiral conformation with C s symmetry of H2bpb which is further enforced by sulfate-bridged coordination and intramolecular hydrogen bonding in the chair-like units, controls over the assembling architectures. Further investigation on the thermal and fluorescent properties of complexes 1–3 shows that the homologous chair-like units in all complexes are stable enough until to 320°C and that the fluorescence nature of H2bpb is not sensitive to its conformations. [Copyright &y& Elsevier]

A four-coordinate zinc(II) coordination polymer, [ZnCl2(H2bpb)]n· CH3OH (H2bpb = 1,2-bis(3-pyridylcarboxylamide)benzene), has been prepared and the crystal structure determined by X-ray diffraction. It crystallizes in the triclinic system, space group [image omitted] with a = 7.898(3) Å, b = 11.792(4) Å, c = 11.911(4) Å, α = 76.051(4)°, β = 89.919(4)°, γ = 78.267(4)°, V = 1052.9(7) Å, Z = 2. The crystal structure consists of chains of complex zig-zaging along the b lattice translation. Fluorescent and thermal properties of the complex were also investigated. [ABSTRACT FROM AUTHOR]

A novel 1D coordinated polymer, {[NaNi(mal)2(μ‐H2O)(H2O)3] · (H2O)2}n (H2mal=malonic acid), has been synthesized and its crystal structure is determined by X‐ray diffraction analysis. Its crystal structure belongs to orthorhombic system with space group p2(1)2(1)2(1). The coordination environment around Ni(II) is described as a distorted octahedron constructed by four oxygen atoms from two trans‐coordinated malonates and two oxygen atoms from two trans‐coordinated water, in which oxygen atom of one water molecule bridges adjacent Ni2+ and Na+. Seven coordination environments around Na center are constructed by four oxygen atoms from four malonates and three oxygen atoms from three water molecules. In the crystal structure of title complex there are complicated hydrogen bonds. [ABSTRACT FROM AUTHOR]

Using V-shaped mixed ligands bis-imidazole and aromatic carboxylic acids, five new coordination polymers namely, {[Ni(B-im)(Br-a)Cl]·H 2 O} n ( 1 ), {[Ni(B-im)(I-a)(H 2 O) 2 ]·0.5H 2 O} n ( 2 ), [Ni(B-im)(I-a)(H 2 O) 2 ] n ( 3 ), [Ni(B-im)(M-a)(H 2 O) 2 ] n ( 4 ) and {[Mn 2 (B-im) 2 (I-a) 2 ]·2H 2 O} n ( 5 ) [B-im = 1,1′-(5-methyl-1,3-phenylene)bis(1H-imidazole), Br-a = 5-bromonicotinic acid, I-a = isophthalic acid and M-a = 5-methylisophthalic acid] were solvothermally synthesized and fully characterized by IR spectra, element analyses, X-ray powder and single-crystal diffractions, and thermogravimetric analyses. Complexes 1 and 2 feature polymeric macrocyclic chain structures containing interesting nanotubular channels, which are constructed by bridging 30-membered macrocyclic [Ni 3 (B-im) 3 ] subunits with Br-a ligands and by bridging folded 20-membered macrocyclic [Ni 2 (B-im) 2 ] subunits with I-a ligands, respectively. Isomorphic complexes 3 and 4 represent double-chain structures containing folded 18-membered macrocyclic [Ni 2 (B-im)(I-a)] subunits and [Ni 2 (B-im)(M-a)] subunits, respectively. Complex 5 is a 2D porous coordination polymer containing novel chiral four-stranded Mn(II) chains consisting of two (B-im)-bridged aspiral chiral chains and two (I-a)-bridged heterochiral coaxial 2 1 -helical chains. The results of thermal gravimetric analyses suggest that the dehydrated frameworks of 1 – 5 are stable up to 320 °C. Additionally, the magnetism of complexes 3 and 5 were also investigated. [ABSTRACT FROM AUTHOR]

Abstract: Reaction of U‐shaped flexible bis(amidopyridine) ligand L with CoCl2·6H2O in DMF produced a 2D coordination polymer [Co(L)2Cl2] n ·4nDMF (1) with 1D channels guesting DMF molecules [L=N,N′-bis((pyridin-3-yl)methyl)pyridine-2,6-dicarboxamide, DMF=N,N′-dimethylformamide]. Complex 1 has corrugated flexible grid-like layers of a (4,4)-connected topology which consists of left- and right-handed helical chains sharing the common Co atoms. Investigation on the thermal stability and porosity shows that the porous network of 1 is rather stable up to 300°C and has obvious adsorption for N2. [Copyright &y& Elsevier]

Abstract: A new ferrocene-containing dicarboxylate ligand, L=5-ferrocene-1,3-benzenedicarboxylic acid, has been prepared. Self-assembly of L, M(II) salts (M=Co and Zn) and chelating ligands dpa or phen (dpa=2,2′-dipyridylamine and phen=1,10-phen) gave rise to four new coordination polymers {[Co(L)(dpa)]·2MeOH} n (1), {[Zn(L)(dpa)]·2MeOH} n (2), {[Co(L)(phen)(H2O)]·MeOH} (3), [Zn(L)(phen)(H2O)]·MeOH (4). The isostructural complexes 1 and 2 possess 1D helical chain structures with 21 screw axes along the b-direction, and the right- and left-handed helical chains are alternate arrayed into 2D layer structures through hydrogen-bonding interactions; while isostructural complexes 3 and 4 are 1D linear chain structures with phen and ferrocene groups of L as pendants hanging on the different sides of the main chain. A structural comparison of complexes 1–4 demonstrated that the characteristics of subsidiary ligands and slight difference in coordination models of L play very important role in the construction of the complexes. In addition, the redox properties of complexes 1–4, as well as the magnetic properties of complexes 1 and 3 are also investigated. [Copyright &y& Elsevier]

Abstract: Three CdII coordination polymers, {[Cd(py)2(dpa)](H2O)} n (1), {[Cd2(4,4′-bipy)2(dpa)2](H2O)} n (2) and {[Cd(bpe)(dpa)](H2O)} n (3) (py=pyridine; H2dpa= diphenic acid; 4,4′-bipy=4,4′-bipyridine; bpe=1,2-bis(4-pyridyl)ethane) were synthesized and characterized by X-ray crystal structure determination. In 1, two syn, anti-carboxylate groups in dpa bridge CdII forming a one-dimensional chain consisting of repeated eight-membered (–Cd–O–C–O–) rings, two pyridine nitrogen atoms occupy the axial positions of six-coordinated CdII. Two-dimensional layer complexes 2 and 3 can be regarded as an extension of 1 through μ-4,4′-bipy and μ-bpe replacing terminal pyridine, respectively. [Copyright &y& Elsevier]

Abstract: Assembly of CdBr2·4H2O and 2,2′-substituted binol derivatives, (S)-2,2′-bis(4-pyridylmethyleneoxy)-1,1′-bi-naphthalene [(S)-L], and (Rac)-2,2′-bis(4-pyridylmethyleneoxy)-1,1′-bi-naphthalene [(Rac)-L], resulted in two one-dimensional chiral chain complexes, {Cd[(S)-L](H2O)Br2} n ·0.5nH2O (1) and {Cd2[(R)-L][(S)-L](H2O)2Br4} n ·2nH2O (2). In complex 1, chain chirality is from axial chirality of BINOL scaffold. In complex 2, racemic ligands including (S)-L and (R)-L locate in the two sides of the equatorial plane, which suggests the ligand self-discrimination during the assembly process. [Copyright &y& Elsevier]