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1.  catena-Poly[[(4-amino­benzoato)aqua­silver(I)]-μ-hexa­methyl­enetetramine] 
In the title coordination polymer, [Ag(C7H6NO2)(C6H12N4)(H2O)]n, the AgI ion is five-coordinated by two carboxyl­ate O atoms from one 4-amino­benzoate anion (L), two N atoms from two different hexa­methyl­enetetramine (hmt) ligands, and one water O atom in a distorted square-pyramidal geometry. The metal atom lies on a mirror plane and the L anion, hmt ligand and water mol­ecule all lie across crystallographic mirror planes. Each hmt ligand bridges two neighboring AgI ions, resulting in the formation of a chain structure along the b axis. The chains are linked into a three-dimensional framework by N—H⋯O and O—H⋯O hydrogen bonds.
doi:10.1107/S1600536809055044
PMCID: PMC2979826  PMID: 21579600
2.  cyclo-Tetra­kis(μ-3-acetyl-4-methyl-1H-pyrazole-5-carboxyl­ato-κ4 N 2,O 3:N 1,O 5)tetra­kis[aqua­copper(II)] tetra­deca­hydrate 
The title compound, [Cu4(C7H6N2O3)4(H2O)4]·14H2O, a tetra­nuclear [2 × 2] grid-type complex with S4 symmetry, contains four CuII atoms which are bridged by four pyrazole­carboxyl­ate ligand anions and are additionally bonded to a water molecule. Each CuII atom is coordinated by two O atoms of the carboxyl­ate and acetyl groups, two pyrazole N atoms of doubly deprotonated 3-acetyl-4-methyl-1H-pyrazole-5-carb­oxy­lic acid and one O atom of a water mol­ecule. The geometry at each CuII atom is distorted square-pyramidal, with the two N and two O atoms in the equatorial plane and O atoms in the axial positions. O—H⋯O hydrogen-bonding interactions additionally stabilize the structure. One of the uncoordinated water molecules shows half-occupancy.
doi:10.1107/S1600536811030832
PMCID: PMC3200935  PMID: 22058869
3.  Di-μ2-methano­lato-bis­(μ-4-methyl-5-sulfanyl­idene-4,5-dihydro-1H-1,2,4-triazolido-κ2 N 1:N 2)di-μ3-oxido-tetra­kis­[dibutyltin(IV)] 
The asymmetric unit of the title distannoxane, [Sn4(C4H9)8(C3H4N3S)2(CH3O)2O2], contains two mol­ecules, each of which lies about an individual center of inversion. The tetra­nuclear mol­ecule features a three-rung-staircase Sn4O4 core in which two independent SnIV atoms are bridged by the triazolide group. The negatively charged N atom of the triazolide group binds to the terminal Sn atom at a shorter distance [Sn—N = 2.262 (3), 2.254 (3) Å] compared with the neutral N atom that binds to the central Sn atom[SnN = 2.617 (4); 2.830 (3) Å]. The oxide O atom is three-coordinate whereas the methano­late O atom is two-coordinate. The terminal Sn atom is five-coordinate in a cis-C3SnNO trigonal–bipyramidal environment, whereas the central Sn atom is six-coordinate in a C2SnNO3 skew-trapezoidal–bipyramidal geometry.
doi:10.1107/S1600536811001917
PMCID: PMC3051783  PMID: 21522898
4.  Di-μ2-methano­lato-bis­(μ-4-methyl-5-sulfanyl­idene-4,5-dihydro-1H-1,2,4-triazolido-κ2 N 1:N 2)di-μ3-oxido-tetra­kis­[dimethyl­tin(IV)] 
The title distannoxane, [Sn4(CH3)8(C3H4N3S)2(CH3O)2O2], lies about a center of inversion; the tetra­nuclear mol­ecule features a three-rung-staircase Sn4O4 core in which the two crystallographically independent SnIV atoms are bridged by the triazolide group. The negatively charged N atom of the triazolide group binds to the terminal Sn atom at a shorter distance [Sn—N = 2.239 (2) Å] compared with the neutral N atom that binds to the central Sn atom [Sn← N = 2.757 (3) Å]. The oxide O atom is three-coordinate whereas the methano­late O atom is two-coordinate. The terminal Sn atom is five-coordinate in a cis-C3SnNO trigonal–bipyramidal environment, whereas the central Sn atom is six-coordinate in a C2SnNO3 skew-trapezoidal–bipyramidal geometry.
doi:10.1107/S1600536811001905
PMCID: PMC3051439  PMID: 21522897
5.  A dinuclear copper complex: bis­(μ-4-amino­benzoato)bis­[aqua(1,10-phenanthroline)copper(II)] dichloride bis(4-amino­benzoic acid) dihydrate 
The title complex, [Cu2(C7H6NO2)2(C12H8N2)2(H2O)2]·2C7H7NO2·2H2O, consists of a dinuclear [Cu2(C7H6NO2)2(C12H8N2)2(H2O)2]2+ cation, two Cl− anions, two 4-amino­benzoic acid mol­ecules and two disordered water mol­ecules (site occupancy factors 0.5). The Cu(II) ion adopts a distorted square-pyramidal geometry formed by two N atoms from the 1,10-phenanthroline ligand and two O atoms of the two 4-amino­benzoic acid ligands and one water O atom. The Cu⋯Cu separation is 3.109 (2) Å. A twofold axis passes through the mid-point of the Cu⋯Cu vector.
doi:10.1107/S1600536808023647
PMCID: PMC2961994  PMID: 21203064
6.  cyclo-Tetra­kis(μ-naphthalene-1,8-dicarboxyl­ato)tetra­kis­[diaqua­(2,2′-bipyridine)­manganese(II)] tetra­hydrate 
In the title centrosymmetric tetra­nuclear complex, [Mn4(C12H6O4)4(C10H8N2)4(H2O)8]·4H2O, two independent MnII ions are coordinated in a slightly disorted octa­hedral environment by two aqua ligands, two naphthalene-1,8-dicarboxyl­ate (1,8-nap) ligands and one bis-chelating 2,2′-bipyridine (2,2′-bipy) ligand. In the crystal, mol­ecules are linked by inter­molecular O—H⋯O hydrogen bonds into chains along [100]. These chains are further linked by weak π–π inter­actions with centroid–centroid distances in the range of 3.609 (2)–3.758 (1) Å, forming a three-dimensional supra­molecular network.
doi:10.1107/S1600536810049433
PMCID: PMC3011697  PMID: 21589355
7.  Octa­butylbis[μ2-4-(diethyl­amino)­benzoato-κ2 O:O′]bis­[4-(diethyl­amino)­benzoato-κO]di-μ3-oxido-tetra­tin(IV) 
The asymmetric unit of the title complex, [Sn4(C4H9)8(C11H14NO2)4O2], consists of two crystallographically independent half-mol­ecules. The other halves are generated by crystallographic inversion centers. In each tetra­nuclear mol­ecule, both of the two independent Sn atoms are five-coordinated, with distorted trigonal–bipyramidal SnC2O3 geometries. One Sn atom is coordinated by two butyl groups, one O atom of the benzoate anion and two bridging O atoms, whereas the other Sn atom is coordinated by two butyl groups, two O atoms of the benzoate anions and a bridging O atom. All the butyl groups are equatorial with respect to the SnO3 trigonal plane. Weak intra­molecular C—H⋯O hydrogen bonds stabilize the mol­ecular structures. In one mol­ecule, two of the butyl groups and the bridging benzoate anion are each disordered over two positions.
doi:10.1107/S1600536811025360
PMCID: PMC3212114  PMID: 22090816
8.  Bis(μ3-pyrimidine-4-carboxyl­ato)bis­(μ2-pyrimidine-4-carboxyl­ato)tetra­kis­(aqua­lithium) 
The asymmetric unit of the title compound, [Li4(C5H3N2O2)4(H2O)4], contains two symmetry-independent LiI ions, two symmetry-independent ligands and two symmetry-independent coordinated water mol­ecules. They form a dinuclear unit in which the two LiI ions are bridged by two carboxyl­ate O atoms from the two ligands. Two dinuclear units related by an inversion centre form the tetra­meric mol­ecule. One of the LiI ions shows a distorted tetra­hedral coordination geometry, the other a distorted trigonal–bipyramidal environment. The tetra­mers are held together by hydrogen bonds in which coordinated water mol­ecules act as donors, and the carboxyl­ate O atoms act as acceptors. A hydrogen bond between coordinated water molecule as donor and a ring N atom as acceptor is also observed.
doi:10.1107/S160053681203142X
PMCID: PMC3414128  PMID: 22904735
9.  Tetra­kis(2-amino-4-methyl­pyridinium) cyclo-tetra-μ2-oxido-tetra­kis­[dioxido­vanadate(V)] tetra­hydrate 
The asymmetric unit of the title compound, (C6H9N2)4[V4O12]·4H2O, contains half of a [V4O12]4− anion, two 2-amino-4-methyl­pyridinium, (2a4mpH)+, cations and two water mol­ecules. One water mol­ecule is disordered over two sets of sites with equal occupancies and the H atoms for this mol­ecule were not included in the refinement. The cation lies on an inversion center with four tetra­hedral VO4 units each sharing two vertices, forming an eight-membered ring. In the crystal, the components are linked by inter­molecular N—H⋯O hydrogen bonds, forming a one-dimensional network along [100]. Further stabilization is provided by weak inter­molecular C—H⋯O hydrogen bonds. In addition, π–π stacking inter­actions with centroid–centroid distances of 3.5420 (18), 3.7577 (18) and 3.6311 (19) Å are observed.
doi:10.1107/S1600536811026912
PMCID: PMC3212164  PMID: 22090866
10.  Bis(4-amino­benzoato)-κ2 O,O′;κO-(2,2′-bipyridine-κ2 N,N′)zinc 
In the title complex, [Zn(C7H6NO2)2(C10H8N2)], the ZnII cation is coordinated by two amino­benzoate anions and one 2,2′-bipyridine ligand in a distorted trigonal–bipyramidal geometry. The carboxyl­ate group of one aminobenzoate anion coordinates to the ZnII cation in a monodentate manner, whereas the carboxyl­ate group of the other amino­benzoate anion chelates the Zn cation with different Zn—O bond lengths. Inter­molecular N—H⋯N and N—H⋯O hydrogen bonding is present in the crystal structure.
doi:10.1107/S1600536811039389
PMCID: PMC3201216  PMID: 22058723
11.  Tetra­kis[μ-4-(dimethyl­amino)benzoato-κ2 O:O′]bis­[(N,N-diethyl­nicotinamide-κN 1)zinc(II)] 
The title mol­ecule, [Zn2(C9H10NO2)4(C10H14N2O)2], is a centrosymmetric binuclear complex, with Zn atoms [Zn⋯Zn′ = 2.8927 (4) Å] bridged by four carboxyl­ate groups from the dimethyl­amino­benzoate (DMAB) ligands. The four carboxyl O atoms around the Zn atom form a distorted square-planar arrangement; the distorted square-pyramidal coordination geometry is completed by the pyridine N atom of the N,N-diethyl­nicotinamide (DENA) ligand. The Zn atom is displaced by 0.3326 (2) Å from the plane of the four O atoms, with an average Zn—O distance of 2.0416 (12) Å. The dihedral angles between the carboxyl­ate groups and the adjacent benzene rings are 5.31 (8) and 11.00 (9)°, while the pyridine ring is oriented at dihedral angles of 66.26 (6) and 37.88 (7)° with respect to the benzene rings. Weak intra­molecular C—H⋯O and inter­molecular C—H⋯π inter­actions are present.
doi:10.1107/S1600536809047473
PMCID: PMC2971944  PMID: 21578613
12.  catena-Poly[bis(μ3-3-aminobenzoato-κ4 N:O:O,O′)bis(μ2-3-aminobenzoato-κ3 O,O′:O)dilead(II)] 
The PbII atom in the title compound, {[Pb2(C7H6NO2)4]}n, is chelated by two 3-aminobenzoato ligands in a distorted pentagonal-bipyramidal coordination geometry with five oxygen donors in the equatorial positions, one nitro­gen donor and one oxygen donor in the axial positions. Two mol­ecules are linked through a centre of inversion, forming a dinuclear entity. These entities are linked in a μ3-bridging mode through the amino N atom and two carboxyl­ate O atoms into a chain along the b axis. Classical inter­molecular N—H⋯O hydrogen bonding is observed in the structure. The supra­molecular structure is consolidated by π–π stacking inter­actions with centroid–centroid distances between benzene rings of 3.837 (8) Å.
doi:10.1107/S1600536810041322
PMCID: PMC3009093  PMID: 21588853
13.  Poly[[dodeca­aqua­bis­(μ3-pyridine-2,6-dicarboxyl­ato)tetra­kis­(μ2-pyridine-2,6-dicarboxyl­ato)tri­calciumdieuropium(III)] 10.5-hydrate] 
In the title compound, {[Ca3Eu2(C7H3NO4)6(H2O)12]·10.5H2O}n, the EuIII ion is nine-coordinated by three tridentate pyridine-2,6-dicarboxyl­ate (PDA) ligands, forming a [Eu(PDA)3]3− building block. The Ca2+ ions adopt two types of coordination geometries. One Ca2+ ion, lying on a twofold rotation axis, is eight-coordinated by four carboxyl­ate O atoms from four PDA ligands and four water mol­ecules, and the other two Ca2+ ions, each lying on an inversion center, are six-coordinated by two carboxyl­ate O atoms from two PDA ligands and four water mol­ecules. The carboxyl­ate groups bridge the EuIII and Ca2+ ions into a three-dimensional porous framework, with channels extending along [010] and [001] in which lattice water mol­ecules are located. Two of the lattice water mol­ecules are disordered over two sets of sites with equal occupancy and one water mol­ecule is 0.25-occupied. Numerous O—H⋯O hydrogen bonds involving the water mol­ecules and carboxyl­ate O atoms are present.
doi:10.1107/S1600536812018028
PMCID: PMC3344405  PMID: 22590167
14.  Tetra­kis(1,10-phenanthroline)bis­(μ-pyridine-2,6-dicarboxyl­ato)(pyridine-2,6-di­carboxyl­ato)dicopper(II)terbium(III) nitrate tetra­hydrate 
The asymmetric unit of the title compound, [Cu2Tb(C7H3NO4)3(C12H8N2)4]NO3·4H2O, consists of one-half of the C 2-symmetric trinuclear coordination cation, one-half of the C 2-symmetric nitrate anion and two water mol­ecules. In the coordination cation, the CuII atom is coordinated by four N atoms from two 1,10-phenanthroline ligands and two O atoms from a bridging–chelating carboxyl­ate group of the pyridine-2,6-dicarboxyl­ate anion, completing a distorted N4O2 octa­hedral coordination environment. The TbIII atom, located on a twofold rotation axis, is nine-coordinated by three tridentate pyridine-2,6-dicarboxyl­ate anions forming an N3O6 donor set. The intra­molecular Cu⋯Tb distance of 5.0592 (11) Å indicates weak inter­actions between the CuII and TbIII atoms. The coordination cations, nitrate anions and water mol­ecules are connected via O—H⋯O hydrogen bonds into layers parallel to the (001) plane. Moreover, there are extensive π–π stacking inter­actions [centroid–centroid distances = 4.332 (7) and 3.878 (5) Å] between the phenanthroline ligands and between phenanthroline and pyridine-2,6-dicarboxyl­ate ligands.
doi:10.1107/S1600536812031686
PMCID: PMC3414140  PMID: 22904747
15.  Tetra­kis(μ2-ferrocene­carboxyl­ato-κ2 O:O′)bis­[(methanol-κO)copper(II)] methanol disolvate 
The complex mol­ecule of the title compound, [Cu2Fe4(C5H5)4(C6H4O2)4(CH3OH)2]·2CH3OH, lies about an inversion centre and contains two centrosymetrically related CuII atoms bridged by four O:O′-bidentante ferrocene­carboxyl­ate anions, leading to a dimeric tetra­bridged unit with a paddle-wheel geometry. The CuII atom has a distorted square-pyramidal coordination environment with four O atoms from four ferrocene­carboxyl­ate ligands in basal positions and an O atom from a methanol mol­ecule in an apical position. One of the two crystallographically independent ferrocenyl groups has a staggered conformation, while the other is eclipsed. The mol­ecules are connected into a chain along the b axis by O—H⋯O hydrogen bonds involving coordinated and uncoordinated methanol mol­ecules and the O atom from a ferrocene­carboxyl­ate unit.
doi:10.1107/S1600536811050185
PMCID: PMC3238738  PMID: 22199615
16.  Tetra­kis(μ-3-chloro­benzoato-κ2 O:O′)bis­[(N,N-di­ethyl­nicotinamide-κN 1)copper(II)] 
In the title centrosymmetric binuclear CuII complex, [Cu2(C7H4ClO2)4(C10H14N2O)2], the two CuII cations [Cu⋯Cu = 2.6314 (4) Å] are bridged by four 3-chloro­benzoate (CB) anions. The four carboxyl­ate O atoms around each CuII cation form a distorted square-planar arrangement, the distorted square-pyramidal coordination geometry being completed by the pyridine N atom of the N,N-di­ethyl­nicotinamide (DENA) mol­ecule. The dihedral angle between the benzene ring and the carboxyl­ate group is 4.49 (11)° in one of the independent CB ligands and 12.00 (10)° in the other. The benzene rings of the independent CB ligands are oriented at a dihedral angle of 84.13 (6)°. In the crystal, weak C—H⋯O hydrogen bonds link the binuclear complex mol­ecules into supra­molecular chains running along [101].
doi:10.1107/S1600536813017881
PMCID: PMC3793677  PMID: 24109264
17.  Bis(μ-chloroacetato-κ2 O:O′)bis(chloro­acetato-κO)di-μ3-oxido-tetrakis[dibenzyl­tin(IV)] 
The title tetra­nuclear complex mol­ecule, [Sn4(C7H7)8(C2H2ClO2)4O2], has crystallographically imposed inversion symmetry. Each Sn atom has a distorted trigonal–bipyramidal geometry, with the equatorial plane formed by an oxido O atom and two C atoms of two benzyl anions. The configuration of the complex is stabilized by a pair of C—H⋯O hydrogen bonds. In the crystal, complex mol­ecules are linked into zigzag chains along [110] by C—H⋯O hydrogen bonds.
doi:10.1107/S1600536810054000
PMCID: PMC3051761  PMID: 21522831
18.  Tetra­kis(μ-2-iodo­benzoato-κ2 O:O′)bis­[aqua­copper(II)] 
In the centrosymmetric binuclear title complex, [Cu2(C7H4IO2)4(H2O)2], the two CuII ions [Cu⋯Cu = 2.6009 (5) Å] are bridged by four 2-iodo­benzoate (IB) ligands. The four nearest O atoms around each CuII ion form a distorted square-planar arrangement, the distorted square-pyramidal coordination being completed by the O atom of the water mol­ecule at a distance of 2.1525 (16) Å. The dihedral angle between the benzene ring and the carboxyl­ate group is 25.67 (13)° in one of the independent IB ligands and 6.44 (11)° in the other. The benzene rings of the two independent IB ligands are oriented at a dihedral angle of 86.61 (7)°. In the crystal, O—H⋯O inter­actions link the mol­ecules into a two-dimensional network. π–π contacts between the benzene rings [centroid–centroid distances = 3.810 (2) and 3.838 (2) Å] may further stabilize the structure.
doi:10.1107/S1600536812010367
PMCID: PMC3343818  PMID: 22589792
19.  Tetra­kis(μ-penta­fluoro­benzoato-κ2 O:O′)bis­[(tetra­hydro­furan-κO)molybdenum(II)] 
In the asymmetric unit of the title compound, [Mo2(C7F5O2)4(C4H8O)2], two independent half-mol­ecules are present, which are completed by a crystallographically imposed center of inversion between the individual Mo atoms. In each mol­ecule, four penta­fluoro­benzoate anions bridge the quadruply bonded Mo2 4+ unit that is, in addition, axially coordinated by two O atoms of tetra­hydro­furan (THF) mol­ecules. In the two independent mol­ecules, the mean Mo—Mo bond length is 2.110 Å. Since the THF mol­ecules are equally disordered over two sets of sites, there are four different Mo—O distances in both half-mol­ecules with an overall mean of 2.542 Å. A zigzag chain is formed by π–π stacking inter­actions between penta­fluoro­phenyl rings, indicated by a centroid–centroid distance of 3.7054 (11) Å and a centroid-to-plane distance of 3.4169 (3) Å. The extension of the unit gives a three-dimensional network structure with the THF mol­ecules located in the voids.
doi:10.1107/S1600536811033411
PMCID: PMC3200930  PMID: 22058882
20.  catena-Poly[[[bis­(4-amino­benzoato-κO)copper(II)]-μ-1,1′-(pentane-1,5-di­yl)diimidazole] trihydrate] 
In the title compound, {[Cu(C7H6NO2)2(C11H16N4)]·3H2O}n, each CuII atom is coordinated by two O atoms from two 4-amino­benzoate anions, and two N atoms from two different 1,1′-(pentane-1,5-di­yl)diimidazole (biim-5) ligands, to furnish a distorted square-planar geometry. The biim-5 ligand coordinates to two copper(II) cations, acting as a bridging ligand; as a result the copper(II) cations are connected to form an infinite chain structure. The polymeric chains are linked through a variety of hydrogen bonds to form a three-dimensional structure.
doi:10.1107/S1600536807064586
PMCID: PMC2915095  PMID: 21200507
21.  Tetra­kis(μ-2,4-difluoro­benzoato)bis­[(2,2′-bipyridine)(2,4-difluoro­benzoato)terbium(III)] 
In the centrosymmetric dinuclear title compound, [Tb2(C7H3F2O2)6(C10H8N2)2], the TbIII ion is coordinated by an N,N′-bidentate 2,2′-bipyridine mol­ecule, and two O,O′-bidentate 2,4-difluoro­benzoate (dfb) anions. One of the latter also bonds to the second TbIII centre through one of its O atoms. The third dfb anion bonds to one Tb atom from each of its O atoms. Thus, the three dfb species have three different coordination modes. This results in an irregular TbN2O7 coordination sphere for the metal ion. The F atoms and their associated H atoms in the simple bidentate dfb anion are disordered over two sets of sites in a 0.672 (10):0.328 (10) ratio.
doi:10.1107/S1600536808043936
PMCID: PMC2968370  PMID: 21581763
22.  (2-Amino­benzoato-κ2 O,O′)(rac-5,5,7,12,12,14-hexa­methyl-1,4,8,11-tetra­aza­cyclo­tetra­decane-κ4 N,N′,N′′,N′′′)nickel(II) perchlorate monohydrate 
In the title salt, [Ni(C7H6NO2)(C16H36N4)]ClO4·H2O, the NiII cation is O,O′-chelated by the benzoate anion and N,N′,N′′,N′′′-chelated by the macrocycle ligand, confering a distorted octa­hedral geometry on the metal atom. The complex cations, perchlorate anions and uncoordinated water mol­ecules are linked by N—H⋯O and O—H⋯O hydrogen bonds into a three-dimensional network. The perchlorate ion is disordered over two positions in a 0.554 (8):0.446 (8) ratio.
doi:10.1107/S1600536810037116
PMCID: PMC2983378  PMID: 21587435
23.  Tetra­kis[μ-4-(methyl­amino)­benzoato-κ2 O:O′]bis­[(N,N-diethyl­nicotinamide-N 1)zinc(II)] dihydrate 
The title mol­ecule, [Zn2(C8H8NO2)4(C10H14N2O)2]·2H2O, is a centrosymmetric binuclear complex, with two ZnII ions [Zn⋯Zn’ = 2.9301 (4) Å] bridged by four methyl­amino­benzoate (MAB) ligands. The four nearest O atoms around each ZnII ion form a distorted square-planar arrangement with the distorted square-pyramidal coordination completed by the pyridine N atom of the N,N-diethyl­nicotinamide (DENA) ligand. Each ZnII ion is displaced by 0.3519 (2) Å from the plane of the four O atoms, with an average Zn—O distance of 2.030 Å. The dihedral angles between carboxyl­ate groups and adjacent benzene rings are 10.57 (10) and 16.63 (12)°, while the benzene rings are oriented at a dihedral angle of 81.84 (5)°. The pyridine ring is oriented at dihedral angles of 40.49 (6) and 51.25 (6)° with respect to the benzene rings. In the crystal structure, inter­molecular O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules into a three-dimensional network. The π–π contact between the inversion-related pyridine rings [centroid–centroid distance = 3.633 (1) Å] may further stabilize the crystal structure.
doi:10.1107/S1600536809040409
PMCID: PMC2971338  PMID: 21578088
24.  Poly[[(μ-benzene-1,4-dicarboxyl­ato)bis­[μ-4-(1H-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthren-2-yl)benzoato]dizinc] tetra­hydrate] 
In the title complex, [Zn2(C8H4O4)(C20H11N4O2)2]·4H2O, the ZnII atom is six-coordinated by two carboxyl­ate O atoms from one bidentate benzene-1,4-dicarboxyl­ate (1,4-BDC) ligand, two carboxyl­ate O atoms from two different monodentate 4-(1H-1,3,7,8-tetra­aza­cyclo­penta­[l]phenanthren-2-yl)benzoate (HNCP) ligands and two HNCP N atoms. The ZnII atoms are bridged by the centrosymmetric 1,4-BDC ligands, forming an extended single-chain structure. Neighbouring single chains are connected by the HNCP ligands from two opposite directions, resulting in a sheet. In addition, there are N—H⋯O hydrogen-bonding inter­actions between adjacent layers. As a result, the polymeric sheets are further extended into a three-dimensional supra­molecular structure.
doi:10.1107/S1600536811040062
PMCID: PMC3246926  PMID: 22219746
25.  Poly[tetra­kis(μ4-4,6-dimethyl-5-nitro­benzene-1,3-dicarboxyl­ato-κ2 O 1:O 1′:O 3:O 3′)bis­(pyridine-κN)dizinc] 
In the title complex, [Zn2(C10H7NO6)2(C5H5N)2]n, the repeat unit is a centrosymmetic tetra-carboxyl­ato-O,O’-bridged dimer in which each ZnII atom is five-coordinated by four O atoms from different dianionic 4,6-dimethyl-5-nitro­iso­phthalate ligands [Zn—O = 2.0283 (18)–2.0540 (19) Å] and one N atom from a pyridine mol­ecule [Zn—N = 2.030 (2) Å] in the axial site of a slightly distorted square-pyramidal coordination sphere. The Zn⋯Zn separation is 2.9750 (6) Å. The complex dimers are extended into a two-dimensional polymeric structure parallel to (100) through bridges provided by the second carboxyl­ate group of the ligand.
doi:10.1107/S1600536811013092
PMCID: PMC3089336  PMID: 21754309

Results 1-25 (453300)