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A heteronuclear metal organic framework containing erbium(III) and cobalt(II) ion based on a rigid ligand of substituted imidazoledicarboxylic acid has been synthesized and characterized by single-crystal X-ray diffraction analysis (CIF file CCDC no. 1019455). It’s formula is [Er2Co2(μ3-HMimda)2(μ3-Mimda)2 · 4H2O] n · 2nH2O, (H3Mimda = 1-H-2-methyl-4,5-imidazole-dicarboxylic acid). The complex crystallizes in the monoclinic system. It possesses an extended grid-like porous structure constructed from corrugated shaped 2D layer. Direct current magnetic susceptibility measurements for indicated the depopulation of the Stark components at low temperature and possible very weak antiferromagnetic interactions within heteronuclear MOF.

Three three-dimensional polymers, namely, [Zn(bpea)(H2O)]n (1), [Cd(bpea)(H2O)]n (2), and [Ni(bpea)(4,4′-bipyridine)(pyridine)]n (3) have been synthesized by the hydrothermal reaction of ZnII, CdII, or NiII salts with biphenylethene-4,4′-dicarboxylic acid. Complexes 1 and 2 have a 2-fold interpenetrating three-dimensional (3D) structure with Pts topology, and complex 1 exhibits strong fluorescent emission bands at 435 and 459 nm in the solid state at room temperature. Complex 3 is a 3D structure with an unprecedented 9-fold interpenetrated Ths topology.

Thin films of 2, 9, 16, 23-tetra-octyloxy copper phthalocyanine (CuPcA 8 ) and 2, 9, 16, 23-tetra-hexadecylocy copper phthalocyanine (CuPcA 16 ) were prepared by Langmuir–Blodgett technique and were characterized by UV–vis spectra. The macro-ring orientation of the two copper phthalocyanine molecules in the films was explored by polarized UV–vis spectra. The linear relationship between the absorption intensity and the number of deposited layers confirmed the highly ordered layered-structure of the films. Moreover, it was found the phthalocyanine molecules were arranged with an angle of 49.8° and 63.6° to the substrates for CuPcA 8 and CuPcA 16 , respectively. The gas-sensing properties of the LB films to methanol, ethanol, and propanol were detected at room temperature. By introducing appropriate substituent onto the macro-ring of the phthalocyanine, the molecular orientation in the films could be controlled, and their gas response might be improved.

SnO2 thin films were prepared by dip-coating from SnO2 sols of 0.5 and 0.1 mol/l. The structure and morphology of the films were analyzed through XRD, UV and AFM methods. The particles in the films were the standard tetragonal phase of SnO2 with spherical morphology. The average size of SnO2 particles was about 87 nm (0.5 mol/l) and 5 nm (0.1 mol/l), respectively. The UV absorbance of the films increased linearly with increasing the deposition layers. The sensitivity of thin films to methanol, ethanol, propanol and acetone was detected at room temperature, and the effects of concentration of SnO2 sols on the morphology and sensitivity of the films were investigated as well. With decreasing the sol concentration, the grain size of the particles reduced, the gas sensing properties to acetone and ethanol increased. Such films with small size could detect ethanol as low as 2 ppm ethanol. Response and recovery time to methanol, ethanol, propanol and acetone at room temperature were within 30 s and 1 min, respectively.

Anatase phase TiO 2 thin films were prepared by dip-coating technique. Atomic force microscope (AFM), X-ray diffractometer (XRD), FT-IR and UV–vis spectra were used for the structural characterization of the TiO 2 films. The results showed that the titania particle was in anatase phase. The FT-IR spectrum exhibited a strong absorption peak at 631 cm −1 which was ascribable to the Ti–O vibration of the anatase phase. The AFM image of the thin films revealed the formation of a uniform but highly porous structure having mean particle size of about 14.89 nm. The results of UV–vis spectra indicated that each coated film could be well transmitted to the substrate. The sensing properties of TiO 2 films were tested to methanol, ethanol and n -propanol at room temperature. The thin films exhibited high response to these gases. When the gas concentration was 10 ppm, the response was 2.6, 2.0 and 7.5 to methanol, ethanol and n -propanol, respectively. The films could detect as low as 3 ppm n -propanol, 10 ppm methanol and 10 ppm ethanol. The response and recovery time were within 1 min and 80 s, respectively.

α-Fe 2 O 3 hydrosol was synthesized by sol–gel method with FeCl 3 ·6H 2 O as the raw material and its thin films were prepared by dip-coating technique. The structure, morphology and spectroscopy of the thin films were characterized by XRD, AFM, UV–vis and FT-IR analysis methods. The results showed that uniform α-Fe 2 O 3 monolayer and multilayers could be obtained at certain dip-coating speed. The particles were pseudocubic shaped, with the mean particle size of about 58 nm. The formation mechanism of α-Fe 2 O 3 particles was explored by IR spectra and the change of the system acidity and conductivity. The results indicated that α-Fe 2 O 3 particles formed from the intermediate complex β-FeOOH. The gas-sensing properties of the multilayers to alcohols with different chain length were measured at room temperature. The thin films exhibited high sensitivity and rapid response–recovery characteristics to these gases. The film can detect C 3 H 7 OH vapor concentration as low as 2 ppm. The response and recovery time of the film to CH 3 OH and C 2 H 5 OH vapor is within 20 and 50 s, respectively.

Octaethyoxyl-2,3-naphthalocyanine and octabutoxy-2,3-naphthalocyanine copper (II) Langmuir monolayers were obtained at air–water interface. The aggregate forms of CuNc(OC4H9)8 in chloroform solution at different aging times were studied. The CuNc(OC2H5)8 and CuNc(OC4H9)8 molecules were successfully transferred onto the solid substrate as Y-type mode by LB technique. The structure of LB films was characterized by IR and electronic spectra. The results show that the CuNc(OC2H5)8 and the CuNc(OC4H9)8 molecules were mainly arranged as J-aggregate in the film. The gas sensitivity of the films to alcohols with different chain lengths was measured at room temperature. The octaethyoxyl-2,3-naphthalocyanine LB films exhibit good sensitivity and good selectivity to propyl alcohol (10–30 ppm). This indicates that CuNc(OC2H5)8 can be exploited as ambient alcohol sensor.

Two new two-dimensional coordination polymers, poly-[[[aqua(2,2'-bipyridine-κ 2 N,N')manganese(II)]-μ 3 -p-Phenyl-euebis(oxyacetato)-κ 3 O:O':O] dihydrate], ([Mn(C 10 H 8 O 6 )-(C 10 H 8 N 2 )(H 2 O)].2H 2 O)} n , (I), and poly[[di-μ-aqua-bis[aquasodium(I)]]-μ 4 -p-phenylenebis(oxyacetato)-κO:O',O:O''', O'''':O'''''], [Na2(C 10 H 8 O. 6 )(H 2 O) 4 ] n , (II), have been synthesized and characterized by X-ray single-crystal diffraction. In (I), there are two 1,4-BDOA 2- [p-phenylenebis(oxyacetate) or, more commonly, benzene-1,4-dioxyacetate] ligands, each lying about inversion centres, while in (II), there is one such ligand and it also has crystallographically imposed inversion symmetry. In (I), each Mn II atom displays an octahedral MnN 2 O 4 configuration, defined by three carboxyl 0 atoms of different 1,4-BDOA 2- groups, two N atoms of one 2,2'-bipyridine ligand and one water molecule. In (II), each Na' atom is octahedrally coordinated by one ether O atom, two carboxyl O atoms of different 1,4-BDOA 2- ligands and three water molecules. The metal ions in complexes (I) and (II) are bridged by 1,4-BDOA 2- groups into two-dimensional layer structures. Furthermore, three-dimensional supramolecular networks are constructed via hydrogen bonds in (I) and (II), and by additional π-π stacking interactions in (I).

La0.6Sr0.4Co0.2Fe0.8O3–Ce0.7Bi0.3O2 (LSCF–CBO) composite electrode has been prepared by polymer–gel method. SEM results showed that the composite electrode formed good contact with Ce0.9Gd0.1O2−δ (CGO) electrolyte after sintering at 900 °C for 2 h. AC impedance spectroscopy and dc polarization measurements were used to study the composite electrode performances in different atmospheres. The ( p O 2 )1/2 relationship of Rp (polarization resistance) with oxygen partial pressure has been observed, which indicated that the oxygen adsorption/desorption process was the reaction rate limiting step. The polarization resistance decreased with increasing CBO contents. The optimum value of 35 vol.% CBO in LSCF resulted in 0.16 Ω cm2 area specific resistivity (ASR) at 706 °C in air, which indicated that the LSCF–CBO composite electrode was a promising cathode material in ITSOFC.

ZnO thin films were prepared by sol–gel dip coating method using zinc acetate dihydrate and 2-ethanolamine as the starting materials. The powder and its thin film were characterized by X-ray diffractometer (XRD), atomic force microscopy (AFM) and IR spectra methods. The results indicated that the ZnO particles crystallized in the wurtzite phase, which were well-distributed in the films with the mean particle size of about 10 nm. The IR spectra of the gel and powders annealed at different temperatures were investigated. It showed that the vibration bands of NH and mono-acetate diminished and the stretching mode of ZnO at 471 cm−1 appeared after the dried gel annealed at 500 °C for 1 h. The diameter, D of ZnO particles in the monolayer was also calculated from the optical spectroscopy curve, which is close to that obtained from AFM observation. The gas-sensing properties of the multi-layers for alcohols with different chain lengths were measured at room temperature. The thin films exhibited high sensitivity and rapid response–recovery characteristics to these gases. The film can detect methanol, ethanol and propyl alcohol vapor as low concentration as 1, 10, and 0.5 ppm, respectively.

A nanoparticulate ferric oxide–copper tris(2,4-di-tert-amylphenoxy)-8-quinolinolylphthalocyanine hybrid ultrathin film was constructed from alternate layers by the Langmuir–Blodgett technique. The composition, morphology and structure of the film were studied by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy, atomic force microscopy, small-angle X-ray diffraction, visible spectroscopy and polarized UV-Vis spectroscopy. All the above analyses suggest that the thin film is a kind of one-dimensional superlattice, composed of organic and inorganic components. The XPS data reveal that the nanoparticulate ferric oxide exists as an α-Fe2O3 phase in the films. Gas-sensing measurements show that the hybrid LB film has very fast response-recovery characteristics towards 2 ppm C2H5OH vapor.

In the title complex, {[Mn(C4O4)(C10H8N2)(H2O)]·H2O}n, each MnII ion has a distorted octa­hedral coordination formed by two N atoms of a 2,2′-bipyridine ligand, three carboxyl O atoms of three different acetyl­ene­dicarboxyl­ate ligands and one coordinated water mol­ecule. The acetyl­ene­dicarboxyl­ate ligands act in a tridentate mode connecting adjacent MnII ions and constructing a two-dimensional structure which can be regarded as an unusual plywood-like stacked network.

In the title complex, {[Ni(C16H10O4)(C12H8N2)(H2O)]·H2O}n, the NiII ion is in a distorted octa­hedral geometry and coordinated by two N atoms of a 1,10-phenanthroline (phen) ligand, three carboxylate O atoms of two different bpea2− ligands and one water mol­ecule. The [Ni(phen)H2O] units are connected by two different 4,4′-(ethene-1,2-di­yl)dibenzoate (bpea2−) bridges, forming a one-dimensional zigzag chain structure. One bpea2− ligand coordinates to Ni in a bis-monodentate fashion, while the other acts as a bis-bidentate chelate.

One of the two independent Zn atoms of the polymeric title compound, [Zn3(C16H10O4)3(C10H8N2)]n, lies on a special position of site symmetry 3 and the other on a special position of site symmetry \overline{3}. The carboxylate ends of the 4,4′-(ethene-1,2-di­yl)dibenzoate dianion, which lies on a special position of site symmetry \overline{1}, each bridge these two independent Zn atoms. The bipyridine-coordinated Zn atom on the threefold axis has a tetra­hedral geometry, whereas the other Zn atom is coordin­ated by the O atoms of six different dianions in an octa­hedral geometry.

In the title complex, [Mn(C4O4)(C12H8N2)(H2O)2]n, each MnII ion is octa­hedrally coordinated by two N atoms of a 1,10-phenanthroline ligand, two carboxylate O atoms of different acetyl­enedicarboxyl­ate (ace2−) ligands and two coordinated water mol­ecules, and the octa­hedral units are connected by ace2− bridges, which adopt a bis-monodentate coordination mode, to form a one-dimensional structure along the [101] direction. A three-dimensional supra­molecular architecture is constructed via hydrogen-bond and π–π inter­actions.

In the title complex, [Co(C4O4)(C12H8N2)(H2O)2]n, the CoII atom exhibits a slightly distorted octa­hedral coordination geometry involving two N atoms from 1,10-phenanthroline, two O atoms from two acetyl­enedicarboxyl­ate (ace2−) dianions and two water O atoms. The ace2− ligand acts in a bis-monodentate mode to connect two adjacent CoII atoms, forming chains along the b axis. A three-dimensional supra­molecular architecture is constructed via O—H⋯O hydrogen bonds and π–π inter­actions.

In the title coordination polymer, [Ca(2-OPA)2(H2O)2]n [2-OPA− is 2-oxo-1,2-di­hydro­pyridine-1-acetate, C7H6NO3], the Ca atom is eight-coordinated by six O atoms from four 2-OPA− ligands and two water mol­ecules, and displays a dodecahedral coordination geometry. Each 2-OPA− ligand bridges two adjacent Ca atoms, forming a chain along the a-axis direction. The Ca⋯Ca separation within the polymer is 4.1022 (8) A. A two-dimensional supramolecular framework is further constructed by hydrogen bonds and weak π–π stacking interactions.

In the title complex, [Cd2(C9H6O5)2(C7H6N2)4(H2O)2]·2H2O, the CdII atoms are linked by two 3-carboxy­phenoxy­acetate groups into a centrosymmetric dimer. Each CdII atom displays a distorted octa­hedral coordination geometry, with three carboxylate O atoms from different 3-carboxy­phenoxy­acetate groups, two N atoms from two benzimidazole co-ligands and one water mol­ecule. Inter­molecular hydrogen bonding leads to a two-dimensional supramolecular network.

The crystal structure of the title complex, [Co(C9H7O5)2(C10H8N2)2(H2O)2]·4H2O or [Co(4-CPOAH)2(4,4′-bipy)2(H2O)2]·4H2O (4,4′-bipy is 4,4′-bipyridine and 4-CPOAH− is the 4-carboxy­phenoxy­acetate monoanion), consists of two independent mononuclear mol­ecules that inter­act through the uncoordinated water mol­ecules. The CoII atoms lie on inversion centers and display an octa­hedral geometry defined by two oxyacetate O atoms of 4-CPOAH− groups, two N atoms of 4,4′-bipy ligands and two water mol­ecules. A three-dimensional supramolecular network structure is formed through hydrogen-bonding inter­actions.

The title mol­ecule, [Co2(C8H7O2)4(C12H8N2)2(H2O)], is a dinuclear CoII complex which is located on a twofold symmetry axis. Each CoII ion is six-coordinated by three O atoms of different phenyl­acetate ligands, two N atoms of the 1,10-phenanthroline ligands and one O atom of a water mol­ecule, giving a distorted octa­hedral geometry. The two CoII atoms are bridged by two phenyl­acetate groups and the water mol­ecule lying on the twofold axis. The Co⋯Co distance is 3.553 (2) A. A one-dimensional supramolecular chain is constructed by π–π stacking inter­actions between adjacent 1,10-phenanthroline mol­ecules.

In the title coordination polymer, [Zn(C9H6O5)(C8H12N2)]n, the ZnII atom is surrounded by two chelating 3-carboxyl­atophenoxy­acetate (3-CPOA) dianions and one 1,10-phenanthroline (phen) ligand. Adjacent ZnII atoms are bridged by 3-CPOA to form a zigzag chain structure. The polymeric chains are connected via π–π stacking inter­actions.

In the title complex, [Mn(C9H7O5)(C10H8N2)(H2O)3](C9H7O5)·H2O or [Mn(3-CPOAH−)(2,2′-bipy)(H2O)3](3-CPOAH−)·H2O (where 3-CPOAH− is the 3-carboxy­phenoxy­acetate monoanion and 2,2′-bipy is 2,2′-bipyridine), the MnII ion has a distorted octa­hedral geometry involving one O atom of the 3-CPOAH− group, two N atoms of the 2,2′-bipy ligand and three water mol­ecules. A three-dimensional supramolecular network is constructed via O—H⋯O hydrogen-bonding and π–π stacking inter­actions.

In the title coordination polymer, {[Ni(4-CPOA)(phen)(H2O)2]·H2O}n (phen is 1,10-phenanthroline, C12H8N2; 4-CPOA is the 4-carboxy­phenoxy­acetate dianion, C9H6O5), each NiII ion displays a distorted octa­hedral geometry, defined by two carboxyl O atoms from two different 4-CPOA ligands, two N atoms from one phen mol­ecule and two coordinated water mol­ecules. The NiII ions are bridged by carboxyl­ate groups of 4-CPOA to form a chain structure. Adjacent polymeric chains are connected via hydrogen bonds and π–π stacking to construct a three-dimensional supramolecular network.

In the title one-dimensional polymer, {[Zn(3-CPOA)(C3H4N2)2]·3H2O}n (3-CPOA2− is the 3-carboxyl­atophenoxy­acetate dianion, C9H6O5), the Zn atom shows tetra­hedral coordination, as it is linked to two N atoms from two imidazole mol­ecules and two carboxyl­ate O atoms from two different 3-CPOA2− groups. Adjacent Zn atoms are linked by 3-CPOA2− ligands into a helical chain. The chains are linked into a three-dimensional network by hydrogen bonds.

The dinuclear title complex, [Ag2(NO3)2(3-PyOH)4]·2H2O (3-PyOH is 3-hydroxy­pyridine, C5H5NO), situated across a crystallographic inversion centre, can be described as a dimeric structure, in which two [Ag(3-PyOH)2] groups are held together by the Ag⋯Ag inter­action [3.317 (1) A]. Each Ag atom is two-coordinate and exists in an approximately linear geometry. The two NO3− ions inter­act with the AgI atoms in a bridging mode through very weak Ag⋯O inter­actions [Ag⋯O = 2.862 (2) and 2.877 (2) A]. A three-dimensional supramolecular framework is formed by O—H⋯O hydrogen bonds.

In the mononuclear title complex, [Ag(NO3)(3-PyOH)2] (3-PyOH = 3-hydroxy­pyridine, C5H5NO), the AgI atom shows a linear geometry defined by two N atoms of the 3-PyOH ligands, and the NO3− anion inter­acts with the AgI atom in a chelating mode through very weak Ag⋯O bonds. A three-dimensional supramolecular framework is formed by both hydrogen bonds and π–π inter­actions.

In the title coordination polymer, [Cd(4-CPOA)(H2O)3]n (where 4-CPOA2− is the 4-carboxyl­ato­phenoxy­acetate dianion, C9H6O5), the CdII ion is seven-coordinate, involving four O atoms of two different 4-CPOA2− ligands and three water mol­ecules, arranged in a pentagonal–bipyramidal geometry. Adjacent CdII ions are linked by the 4-CPOA2− groups in bidentate mode, giving rise to a zigzag chain with a closest Cd⋯Cd distance of 10.310 (5) A. The chains are further linked by O—H⋯O hydrogen bonds to form a supramolecular three-dimensional network.

The CoII atom in the title coordination polymer, [Co(C9H6O5)(C12H8N2)(H2O)]n, displays a distorted octahedral geometry defined by three carboxyl O atoms from two independent 4-carboxy­phenoxy­acetate groups, two N atoms from one 1,10-phenanthroline mol­ecule and one water mol­ecule. The CoII atoms are bridged by carboxyl­ate groups in monodentate and bidentate modes, forming a chain structure. Adjacent polymeric chains are connected via hydrogen-bond interactions into a double-chain structure. Furthermore, these chains are stacked through π–π interactions to construct a two-dimensional supramolecular network.

A novel two-dimensional sheet cadmium(II) coordination polymer [Cd(μ-3-PyO–N,O)2(3-PyOH)2]n, containing neutral and deprotonated 3-hydroxypyridine ligands has been synthesized and shown to exhibit strong blue fluorescent emission in the solid state.

The CdII atom in the title coordination polymer, [Cd(4-CPOA)(1,10-phen)(H2O)]n (1,10-phen is 1,10-phenanthroline, C12H8N2, and 4-CPOA2− is the 4-carboxy­phenoxy­acetate dianion, C9H6O5), shows a distorted octahedral geometry, defined by three carboxyl O-atom donors from two independent 4-CPOA2− groups, two N-atom donors from one 1,10-phen ligand, and one water molecule. The CdII ions are bridged by carboxyl­ate groups in mono- and bidentate modes, forming a chain structure. The polymeric chains are connected via O—H⋯O hydrogen bonds and π–π stacking interactions into a two-dimensional layer structure.

The asymmetric unit of the title one-dimensional coordination polymer, {[Co(C10H8N2)(H2O)4](C9H6O5)·H2O}n, comprises two half-cations, [Co(4,4′-bipy)(H2O)4]22+ (4,4′-bipy is 4,4′-bi­pyridine), one 3-carboxyl­ato­phenoxy­acetate (3-CPOA2−) dianion and one non-coordinated water mol­ecule. The CoII ions, both of which are located on inversion centres, have approximately octahedral geometries, involving two N atoms of the centrosymmetric 4,4′-bipy ligand and four water mol­ecules. Adjacent CoII atoms are linked by 4,4′-bipy ligands into a chain, the shortest Co⋯Co separation within the polymeric chain being 11.456 (2) A. The chains are further linked by hydrogen-bonding and π–π stacking interactions, generating a three-dimensional network.

In the title two-dimensional coordination polymer, [Cu(C9H6O5)(C7H6N2)]n, each CuII atom exists in a distorted square-pyramidal coordination environment, defined by one N atom from the terminal benz­imidazole mol­ecule and four carboxyl O atoms derived from three different 3-carboxyl­ato­phenoxy­acetate (3-CPOA) dianions. The tetradentate 3-CPOA ligand forms three bonds to adjacent Cu atoms to form chains that are linked to neighboring chains, via a fourth Cu—O bond, so as to form a layer structure that is further stabilized by hydrogen bonds.

In the title coordination polymer, [Cu(HIDC)(1,10-phen)]n (HIDC2− is the 4-carboxy­imidazole-5-carboxyl­ate dianion, C5H2N2O42−, and 1,10-phen is 1,10-phenanthroline, C12H8N2), the CuII atom shows a distorted octahedral coordination configuration, defined by two N atoms from a terminal 1,10-phen mol­ecule, two N atoms and two O atoms from two individual HIDC2− groups. Adjacent CuII atoms are bridged by HIDC2− groups, forming a one-dimensional chain structure. The Cu⋯Cu separation within the polymer is 6.132 (4) A. The chains are linked into a two-dimensional supramolecular network via π–π stacking interactions.

Each seven-coordinate CdII atom in the title coordination polymer, poly­[[bis(1H-imidazole-κN3)­cadmium(II)]-μ3-m-phenyl­enebis­(oxy­acetato)], [Cd(1,3-BDOA)(C3H4N2)2]n (1,3-BDOA2− is the benzene-1,3-dioxy­acetate dianion, C10H8O6), displays a distorted monocapped octahedral coordination geometry, defined by two N atoms from the imidazole ligands and five O atoms from three 1,3-BDOA2− anions. Adjacent CdII atoms are bridged by two 1,3-BDOA2− ligands, forming a one-dimensional double-chain structure, with Cd⋯Cd separations of 4.014 (3) A across the double chain and 13.105 (2) A along the chain. A network of N—H⋯O interchain hydrogen bonds is also present.

In the title coordination polymer, [Zn(C9H6O5)(C10H8N2)(H2O)]n, the ZnII ion displays a distorted octahedral coordination configuration, defined by two N atoms from the 2,2′-bi­pyridine ligand, three carboxyl­ate O atoms from two 4-carboxyl­ato­phenoxy­acetate dianions and one water mol­ecule. Adjacent ZnII atoms are linked by carboxyl­ate groups into zigzag chains with a Zn⋯Zn separation of 9.710 (3) A across the chains. Intermolecular hydrogen bonds serve to assemble the chains into a double-chain structure.

In the title compound, poly­[cadmium(II)-μ4-m-phenyl­enebis­(oxy­acetato)], [Cd(C10H8O6)]n, the CdII atom exists in a distorted monocapped octahedral coordination environment with seven O atoms from four carboxyl­ate groups. The Cd atoms are bridged by benzene-1,3-dioxy­acetate dianions with tridentate and tetradentate modes of the oxy­acetate groups, leading to a two-dimensional layer structure parallel to (001).

In the asymmetric unit of the title compound, [Mn(C10H8O6)(H2O)3]n, the two half-MnII atoms lie on inversion centres. One MnII atom is in an octahedral configuration, defined by two O atoms from two monodentate carboxyl­ate groups and four water mol­ecules, and the other MnII atom exists in a different octahedral coordination environment, defined by four O atoms from four monodentate carboxyl­ate groups and two water mol­ecules. The MnII atoms are bridged by a benzene-1,3-dioxy­acetate dianion in monodentate and bridging-bidentate modes, forming a two-dimensional layer structure.

In the title one-dimensional coordination polymer, {[Co(4-CPOA)(3-PyOH)2(H2O)2]·H2O}n [4-CPOA2− is the 4-carboxy­phenoxy­acetate dianion (C9H6O52−) and 3-PyOH is 3-hydroxy­pyridine (C5H5NO)], the CoII atom has a distorted octahedral coordination geometry, defined by two carboxyl O-atom donors from two 4-CPOA2− groups, two N-atom donors from two 3-PyOH co-ligands and two water mol­ecules. The CoII atoms are bridged by bis-monodentate carboxyl­ate groups, forming a one-dimensional chain structure. The Co⋯Co separation within the polymer is 10.862 (3) A. The chains are linked into a three-dimensional supramolecular network via O—H⋯O hydrogen bonds.

In the title complex {systematic name: aqua­[p-phenyl­enebis­(dioxy­acetato)-κO]­tetrakis(1H-imidazole-κN3)­nickel(II) mono­hydrate}, [Ni(C10H8O6)(C3H4N2)4(H2O)]·H2O, the NiII atom shows a distorted octahedral configuration, defined by one carboxyl O atom of the benzene-1,3-dioxy­acetate group, four N atoms from four imidazole ligands and one water mol­ecule. A three-dimensional supramolecular network is constructed by hydrogen-bonding and π–π stacking interactions.

In the title complex, [Zn(H2IDC)2(H2O)2] (where H2IDC− is the 5-carboxy-1H-imidazole-4-carboxyl­ate monoanion, C5H3N2O4), the ZnII atom is located on an inversion centre, is trans-coordinated by two N,O-bidentate H2IDC− ligands and two water mol­ecules and shows an approximately octahedral configuration. A three-dimensional supramolec­ular architecture is formed via hydrogen-bond interactions.

In the title one-dimensional coordination polymer, [Cd(HIDC)(1,10-phen)]n (where HIDC2− is the imidazole-4,5-di­carboxyl­ate dianion, C5H2N2O42−, and 1,10-phen is 1,10-phenanthroline, C12H8N2), the CdII atom has a distorted octahedral coordination geometry, defined by two N donors from a chelating 1,10-phen mol­ecule, two N-atom donors and two O-atom donors from two individual HIDC2− groups. Adjacent CdII ions are bridged by HIDC2− groups, resulting in a one-dimensional chain structure. The Cd⋯Cd separation within the polymer is 6.661 (2) A. The chains are linked into a two-dimensional supramolecular network via π–π stacking interactions.

The title complex crystallizes as a methanol solvate, [Cu2(C16H14O4N2)2(C5H5N)2]·2CH4O. The dinuclear complex is generated from the atoms of the asymmetric unit by inversion symmetry, resulting in a Cu⋯Cu separation of 3.497 (3) A. The copper(II) species has a square-pyramidal geometry, with the basal plane defined by two O atoms and one N atom from the hydrazone ligand and a pyridine N atom. The apical site is occupied by a phenolate O atom in the symmetry-generated hydrazone ligand, which also bonds to the second Cu atom. Intramolecular O—H⋯N hydrogen bonds are formed between the methanol solvent mol­ecules and the uncoordinated N atoms of the hydrazone ligand.

The title complex, [Co(2-OPA)2(H2O)4] [2-OPA− = (2-oxo-1,2-dihydropyridin-1-yl)­acetate, C7H6NO], is a neutral mononuclear compound. The CoII atom, located on an inversion center, has an octahedral coordination geometry involving two carbonyl O atoms of different 2-OPA− ligands and four water mol­ecules. A layer structure is formed via O—H⋯O intermolecular hydrogen bonds.

In the title complex, [Zn(1,4-BDOA)(H2O)4]n or [Zn(C10H8O6)(H2O)4]n (where 1,4-BDOA2− is the benzene-1,4-dioxy­acetate dianion), the ZnII atom and the 1,4-BDOA2− ligand build up a one-dimensional polymer chain along c. The ZnII atom, located on an inversion center, shows an octahedral coordination geometry, defined by two carboxyl O atoms of different benzene-1,4-dioxy­acetate ligands and four water mol­ecules. Adjacent ZnII atoms are bridged by bis-monodentate carboxyl­ate groups of the centrosymmetric 1,4-BDOA2− ligands, to furnish the one-dimensional chain along the c axis; the Zn⋯Zn separation within the polymer is 14.717 (3) A. A hydrogen-bonded supramolecular architecture is formed via O—H⋯O intermolecular hydrogen bonds.

The hydro­xide group in the centrosymmetric title complex, {[Zn4(C9H6O5)3(OH)2(C10H8N2)2]·2H2O}n, which adopts a three-dimensional network structure, bridges three Zn atoms. One of the symmetry-independent di­carboxyl­ate groups chelates to a Zn—OH—Zn unit through the carboxyl group on the aromatic ring, while its other oxy­acetate arm uses only one O atom for binding. The other di­carboxyl­ate dianion is disordered over a center of inversion and functions as a chelating ligand to two Zn—OH—Zn units. The modes of coordination by the hydro­xide, heterocycle and di­carboxyl­ate ligands give rise to tetrahedral coordination for one Zn atom and octahedral coordination for the other.

The Zn atom in the title mononuclear complex, [Zn(C2H3O3)2(C12H8N2)]·2H2O, exists in an octahedral coord­ination environment defined by two hydroxy O atoms, two carboxyl­ate O atoms from different glycolate (hydroxy­acetate) ligands and two N atoms from one phenanthroline (phen) ligand. The Zn atom occupies a special position with twofold symmetry. A layer structure is formed via O—H⋯O hydrogen bonds involving the water molecules.