Poly[di-µ(3)-hy-droxy[µ(4)-5-(4-carb-oxy-phen-yl)pyridine-2-carboxyl-ato-κ(5)N,O(2):O(2'):O(4):O(4')]dicadmium].

The asymmetric unit of the title polymeric complex, [Cd(2)(C(13)H(7)NO(4))(OH)(2)](n), consists of two independent Cd(II) atoms, one 5-(4-carb-oxy-phen-yl)pyridine-2-carboxyl-ate ligand and two hy-droxy groups. One Cd(II) atom is six-coordinated by two O atoms from two ligand mol-ecules and by four µ(3)-OH groups in a distorted trigonal-prismatic geometry. The other is five-coordinated by one N and two O atoms from two ligands and by two µ(3)-OH groups, forming a distorted square-pyramidal geometry. The two independent Cd(II) atoms are connected by the ligand mol-ecules and the OH groups into a three-dimensional framework. O-H⋯O hydrogen bonds between the OH groups and the carboxyl-ate O atoms are observed.

Constructing mixed-metal coordination polymers from copper(II)-pyridinedicarboxylate metalloligands.

In the mixed-metal complex catena-poly[bis[diaquasilver(I)] [bis[aquacopper(II)]-mu(3)-pyridine-2,5-dicarboxylato-2':1:1'kappa(5)N,O(2):O(5):O(5),O(5')-mu-pyridine-2,5-dicarboxylato-2:1kappa(4)N,O(2):O(5),O(5')-disilver(I)-mu(3)-pyridine-2,5-dicarboxylato-1:1':2''kappa(5)O(5),O(5'):O(5):N,O(2)-mu-pyridine-2,5-dicarboxylato-1':2'''kappa(4)O(5),O(5'):N,O(2)] hexahydrate], {[Ag(H(2)O)(2)][AgCu(C(7)H(3)NO(4))(2)(H(2)O)].3H(2)O}(n), a square-pyramidal Cu(II) center is coordinated by two N atoms and two O atoms from two pyridine-2,5-dicarboxylate (2,5-pydc) ligands and a water molecule, forming a [Cu(2,5-pydc)(2)(H(2)O)](2-) metalloligand. One Ag(I) center is coordinated by five O atoms from three 2,5-pydc ligands and, as a result, the [Cu(2,5-pydc)(2)(H(2)O)](2-) metalloligands act as linkers in a unique mu(3)-mode connecting Ag(I) centers into a one-dimensional anionic double chain along the [101] direction. The other Ag(I) center is coordinated by two water molecules, forming an [Ag(H(2)O)(2)](+) cation. Four adjacent Ag(I) centers are associated by Ag...Ag interactions [3.126 (1) and 3.118 (1) A], producing a Z-shaped Ag(4) unit along the [010] direction and connecting the anionic chains into a two-dimensional layer structure. This study offers information for engineering mixed-metal complexes based on copper(II)-pyridinedicarboxylate metalloligands.

catena-Poly[diammonium [diaqua-bis(pyridine-2,4-dicarboxyl-ato-κN,O)cuprate(II)] [[diaqua-copper(II)]-µ-pyridine-2,4-dicarboxyl-ato-κN,O:O-[tetra-aqua-cadmium(II)]-µ-pyridine-2,4-dicarboxyl-ato-κO:N,O] hexa-hydrate].

The title mixed-metal complex, {(NH(4))(2)[Cu(C(7)H(3)NO(4))(2)(H(2)O)(2)][CdCu(C(7)H(3)NO(4))(2)(H(2)O)(6)]·6H(2)O}(n), contains one octa-hedrally coordinated Cd(II) center and two octa-hedrally coordinated Cu(II) centers, each lying on an inversion center. The two Cu(II) atoms are each coordinated by two O atoms and two N atoms from two 2,4-pydc (2,4-H(2)pydc = pyridine-2,4-dicarboxylic acid) ligands in the equatorial plane and two water mol-ecules at the axial sites, thus producing two crystallographically independent [Cu(2,4-pydc)(2)(H(2)O)(2)](2-) metalloligands. One metalloligand exists as a discrete anion and the other connects the Cd(H(2)O)(4) units, forming a neutral chain. O-H⋯O and N-H⋯O hydrogen bonds connects the polymeric chains, complex anions, ammonium cations and uncoordinated water mol-ecules into a three-dimensional supra-molecular network.

Assembly of the highest connectivity Wells-Dawson polyoxometalate coordination polymer: the use of organic ligand flexibility.

Through tuning the length of flexible bis(triazole) ligands and different metal ion coordination geometries, four Wells-Dawson polyoxoanion-based hybrid compounds, [Cu 6(btp) 3(P 2W 18O 62)].3H 2O ( 1) (btp = 1,3-bis(1,2,4-triazol-1-y1)propane), [Cu 6(btb) 3((P 2W 18O 62)].2H 2O ( 2), [Cu 3(btb) 6(P 2W 18O 62)].6H 2O (btb = 1,4-bis(1,2,4-triazol-1-y1)butane) ( 3), and [Cu 3(btx) 5.5((P 2W 18O 62)].4H 2O (btx = 1,6-bis(1,2,4-triazol-1-y1)hexane) ( 4), were synthesized and structurally characterized. In compound 1, the metal-organic motif exhibits a ladder-like chain, which is further fused by the ennead-dentate [P 2W 18O 62] (6-) anions to construct a 3D structure. In compound 2, the metal-organic motif exhibits an interesting Cu-btb grid layer, and the ennead-dentate polyoxoanions are sandwiched by two Cu-btb layers to construct a 3D structure. Compound 3 exhibits a (4 (2).6 (2).8 (2)) 3D Cu-btb framework with square and hexagonal channels arranged alternately. The hexa-dentate polyoxoanions incorporate only into the hexagonal channels. In compound 4, there exist two sets of (6 (1).10 (2)) 2(6 (1).8 (2).10 (3)) 3D Cu-btx frameworks to generate a 2-fold interpenetrated structure into which the penta-dentate polyoxoanions are inserted to construct a 3D structure. The structural analyses reveal that the length of flexible bis(triazole) ligands and metal ion coordination geometries have a synergic influence on the structures of this series. To our knowledge, they have the highest connectivity for the Wells-Dawson polyoxometalate coordination polymers to date.

High-dimensional assembly depending on polyoxoanion templates, metal ion coordination geometries, and a flexible bis(imidazole) ligand.

By introducing the flexible 1,1'-(1,4-butanediyl)bis(imidazole) (bbi) ligand into the polyoxovanadate system, five novel polyoxoanion-templated architectures based on [As(8)V(14)O(42)](4-) and [V(16)O(38)Cl](6-) building blocks were obtained: [M(bbi)(2)](2)[As(8)V(14)O(42)(H(2)O)] [M = Co (1), Ni (2), and Zn (3)], [Cu(bbi)](4)[As(8)V(14)O(42)(H(2)O)] (4), and [Cu(bbi)](6)[V(16)O(38)Cl] (5). Compounds 1-3 are isostructural, and they exhibit a binodal (4,6)-connected 2D structure with Schläfli symbol (3(4) x 4(2))(3(4) x 4(4) x 5(4) x 6(3))(2), in which the polyoxoanion induces a closed four-membered circuit of M(4)(bbi)(4). Compound 4 exhibits an interesting 3D framework constructed from tetradentate [As(8)V(14)O(42)](4-) cluster anions and cationic ladderlike double chains. There exists a bigger M(8)(bbi)(6)O(2) circuit in 4. The 3D extended structure of 5 is composed of heptadentate [V(16)O(38)Cl](6-) anions and flexural cationic chains; the latter consists of six Cu(bbi) segments arranged alternately. It presents the largest 24-membered circuit of M(24)(bbi)(24) so far observed made of bbi molecules and transition-metal cations. Investigation of their structural relations shows the important template role of the polyoxoanions and the synergetic interactions among the polyoxoanions, transition-metal ions, and flexible ligand in the assembly process. The magnetic properties of compounds 1-3 were also studied.

Poly[di-mu3-chloro-mu2-trans-1,2-di-4-pyridylethylene-dicopper(I)]: a two-dimensional organic-inorganic hybrid constructed from linear CuCl clusters and bridging ligands.

The structure of the title compound, [Cu2Cl2(C12H10N2)](n), contains infinite CuCl staircase-like chains, which lie about inversion centres. The trans-1,2-di-4-pyridylethylene molecules also lie about inversion centres and connect the CuCl chains through Cu-N coordination bonds into a two-dimensional organic-inorganic hybrid network. The planar sheets are stacked along the c axis and associated through weak C-H...Cl interactions. The results show a reliable structural motif with controllable separation of the CuCl chains by variation of the length of the ligand.

Interactions of thiamine with polymeric halogenocadmate anions in the organic-inorganic hybrid compound (thiaminium)[Cd3Br4.4Cl3.6].

The structure of poly[3-[(4-amino-2-methylpyrimidin-1-ium-5-yl)methyl]-5-(2-hydroxyethyl)-4-methylthiazolium octa-mu-bromo/chloro(4.4/3.6)-tricadmate(II)], [(C12H18N4OS)[Cd3 Br4.41Cl3.59]]n consists of hydrogen-bonded thiamine molecules and polymeric cadmium bromide/chloride anions in an organic-inorganic hybrid fashion. The one-dimensional anion ribbons are formed by edge-sharing octahedra and vertex-sharing tetrahedra. Thiamine molecules adopting the S conformation are linked to anions via three types of interactions, namely an N(amino)-H...anion...thiazolium bridging interaction, an N(pyrimidine)-H...anion hydrogen bond and an O(hydroxy)-H...anion hydrogen bond.

Thiamine tetraphenylborate monohydrate: a two-dimensional hydrogen-bonded network with (4,4)-topology.

The title compound, 3-[(4-amino-2-methylpyrimidin-5-yl)methyl]-5-(2-hydroxyethyl)-4-methylthiazolium tetraphenylborate monohydrate, C12H17N4OS+.C24H20B-.H2O, is a salt in which the thiamine cations are linked by hydrogen bonds into a two-dimensional network having (4,4)-topology. The stacked sheets form channels, which are occupied by the anions; the cations and anions are linked by C-H...pi(arene) hydrogen bonds.

Synthesis and characterization of binuclear molybdenum-polycarboxylate complexes with sulfur bridges.

A group of four binuclear sulfur-bridged molybdenum-polycarboxylato complexes with homocitrate, citrate, cysteine, ethylenediaminetetraacetate ligands, respectively, have been synthesized and characterized. These complexes were prepared in order to study the interaction of Mo and homocitrate in the FeMo-co of nitrogenases. In the structures of K4(NH4)2[Mo2O2S2(C6H4O7)2].10H2O (2), (NH4)2[Mo2O2S2(C3H5SNO2)2].5H2O (3) and (NH4)2[Mo2O2S2(C10H12N2O8)].3.5H2O (4), molybdenum (V) atom adopts a distorted octahedral arrangement through a terminal oxygen atom, two bridging sulfur atoms and three atoms from the ligand (hydroxyl, alpha-, beta-carboxylates, sulfide or amine). The coordination mode of homocitrate ligand in K5(NH4)[Mo2O2S2(C7H5O7)2].3H2O.CH3OH (1) has been proposed in a tridentate fashion via its hydroxyl and a pair of carboxylate groups (alpha-, beta-carboxylates). The electrochemical properties of these complexes have been discussed.

Ammonium 4-nitrophenylarsonate.

In the crystal structure of the title compound, (NH(4))[AsO(2)(OH)(C(6)H(4)NO(2))], the 4-nitrophenylarsonate anions and ammonium cations are linked through hydrogen bonds to form infinite chains along the b axis. The hydroxyl O atom of the 4-nitrophenylarsonate anion acts as both an acceptor and a donor of hydrogen bonds. All atoms are located in general positions.