Crystal engineering of Cu-containing metal–organic coordination polymers under hydrothermal conditions

cis-Protected palladium(ii) based binuclear complexes as tectons in crystal engineering and the imperative role of the cis-protecting agent

The shape and molecular packing of cis-protected Pd(ii) based binuclear complexes depends upon the ligand and cis-protecting agents.

pH-Dependent Self-Assembly of Ladder-Like Lanthanide Chains with Copper(I) Halide Clusters

Through adjustment of the pH value of the reaction system, two series of 3 D lanthanide(III)-copper(I) coordination polymers, namely [Ln₂ (na)₇ Cu₆ Br₅ (H₂ O)₂ ] [Ln=La (1), Ce (2), Pr (3), Nd (4), Sm (5), Eu (6), Gd (7), Tb (8)] and [La₂ (na)₇ Cu₃ Br₂ (H₂ O)₂ ]⋅H₂ O (9) (na^- =nicotinate), are synthesized hydrothermally and characterized fully. It is worth nothing that these two series of heterometallic compounds are constructed from similar ladder-like Ln-organic chains, but different copper(I) halide clusters. The luminescence properties of the compounds with Nd (4), Eu (6), and Tb (8) are also investigated.

Supramolecular architectures in Co(II) and Cu(II) complexes with thiophene-2-carboxylate and 2-amino-4,6-dimethoxypyrimidine ligands

The coordination chemistry of mixed-ligand complexes continues to be an active area of research since these compounds have a wide range of applications. Many coordination polymers and metal-organic framworks are emerging as novel functional materials. Aminopyrimidine and its derivatives are flexible ligands with versatile binding and coordination modes which have been proven to be useful in the construction of organic-inorganic hybrid materials and coordination polymers. Thiophenecarboxylic acid, its derivatives and their complexes exhibit pharmacological properties. Cobalt(II) and copper(II) complexes of thiophenecarboxylate have many biological applications, for example, as antifungal and antitumor agents. Two new cobalt(II) and copper(II) complexes incorporating thiophene-2-carboxylate (2-TPC) and 2-amino-4,6-dimethoxypyrimidine (OMP) ligands have been synthesized and characterized by X-ray diffraction studies, namely (2-amino-4,6-dimethoxypyrimidine-κN)aquachlorido(thiophene-2-carboxylato-κO)cobalt(II) monohydrate, [Co(C5H3O2S)Cl(C6H9N3O2)(H2O)]·H2O, (I), and catena-poly[copper(II)-tetrakis(μ-thiophene-2-carboxylato-κ(2)O:O')-copper(II)-(μ-2-amino-4,6-dimethoxypyrimidine-κ(2)N(1):N(3))], [Cu2(C5H3O2S)4(C6H9N3O2)]n, (II). In (I), the Co(II) ion has a distorted tetrahedral coordination environment involving one O atom from a monodentate 2-TPC ligand, one N atom from an OMP ligand, one chloride ligand and one O atom of a water molecule. An additional water molecule is present in the asymmetric unit. The amino group of the coordinated OMP molecule and the coordinated carboxylate O atom of the 2-TPC ligand form an interligand N-H...O hydrogen bond, generating an S(6) ring motif. The pyrimidine molecules also form a base pair [R2(2)(8) motif] via a pair of N-H...N hydrogen bonds. These interactions, together with O-H...O and O-H...Cl hydrogen bonds and π-π stacking interactions, generate a three-dimensional supramolecular architecture. The one-dimensional coordination polymer (II) contains the classical paddle-wheel [Cu2(CH3COO)4(H2O)2] unit, where each carboxylate group of four 2-TPC ligands bridges two square-pyramidally coordinated Cu(II) ions and the apically coordinated OMP ligands bridge the dinuclear copper units. Each dinuclear copper unit has a crystallographic inversion centre, whereas the bridging OMP ligand has crystallographic twofold symmetry. The one-dimensional polymeric chains self-assemble via N-H...O, π-π and C-H...π interactions, generating a three-dimensional supramolecular architecture.

Dicarboxylate ligand-modulated assembly of new luminescent zinc(ii) coordination polymers with in situ formed tetrazole ligands: an experimental and theoretical study

In situ hydrothermal reactions of 4-(1H-imidazol-1-yl)benzonitrile, Zn(NO₃)₂ and NaN₃ with H₂DPA or H₂PYDC gave rise to two new zinc(ii) coordination polymers, which exhibit different intriguing architectures and photoluminescence properties.

Roles of temperature, solvent, M/L ratios and anion in preparing complexes containing a Himta ligand

Nine new complexes based on the Himta ligand were hydrothermally synthesized and structurally characterized. A systematic and comprehensive investigation of four influence factors on some complex architectures was carried out.

Facile method to disperse nonporous metal organic frameworks: composite formation with a porous metal organic framework and application in adsorptive desulfurization

It is generally not easy to utilize nonporous metal organic frameworks (MOFs) with a large crystal size (especially for catalysis or adsorption) because their surface area is low and the majority of the active sites exist inside the MOFs. Composing with porous materials may be one way to disperse the nonporous materials. In this study, a nonporous/nonsoluble MOF (in which the particle size was much larger than the cavity size of the porous MOFs) containing Cu(I) ((Cu2(pyz)2(SO4)(H2O)2)n, denoted as CP) was composed with typical porous MOFs such as MIL100(Fe) (iron-benzenetricarboxylate) and CuBTC (cupper-benzenetricarboxylate). The Cu(I) species of the nonporous MOF was effectively utilized for the adsorptive desulfurization (ADS) of model fuel. Even though the porosities of the composed MOFs decreased as the content of CP increased, the adsorption capacity increased as the content of CP increased (up to a certain content). Considering the negligible capacity of CP for ADS, the enhanced adsorption capacity may be a result of the well-dispersed Cu(I), which is known to be beneficial for ADS via π-complexation. The dispersed CP was also observed by transmission electron microscopy mapping. Therefore, composing a nonporous MOF with porous MOF is a new and facile way to disperse/utilize the active sites of a nonporous MOF.

A two-dimensional zinc(II) coordination polymer createdvia in situligand synthesis involving C—N bond formation

The novel ZnIIcoordination polymer poly[{μ4-2-[3-(pyridin-2-yl)-1H-pyrazol-3-yl]butanedioato}zinc(II)], [Zn(C12H9N3O4)]n, has been synthesized hydrothermally and structurally characterized. The results demonstrate that the complex shows two-dimensional neutral wave-like layers. The complex was prepared by the conjugate addition reaction of 2-(1H-pyrazol-3-yl)pyridine tocis-fumaric acid in the presence of Zn(OAc)2·2H2O (OAc is acetate) at 413 K.

Polyanionic clusters embedded in lattice-type hydrogen bonding networks involving in situ bond activation and coupling of organic cations

Grid-type hydrogen bonding networks of organic cations are used to capture pseudo-spherical Keggin-type anionic clusters.

Exceptional sensitivity to the synthetic approach and halogen substituent for Zn(ii) coordination assemblies with 5-halonicotinic acids

The significant influence of the synthetic approach and halogen substituent on Zn(ii) coordination assemblies with 5-halonicotinic acids has been demonstrated.

Syntheses, structures, topologies, and luminescence properties of four coordination polymers based on bifunctional 6-(4-pyridyl)-terephthalic acid and bis(imidazole) bridging linkers

Four CPs, with the structure ranged from 2D sheet to 3D 3-fold penetrated net, have been designed with the mixed-ligand strategy of bifunctional 6-(4-pyridyl)-terephthalic acid and bis(imidazole) bridging linkers.

Poly[(μ-pentafluorobenzoato-κ²O:O')(pentafluorobenzoato-κO)(μ-pyrazine-κ²N:N')copper(II)]: a coordination polymer linked into a three-dimensional network by intermolecular C-H···F-C interactions

In the title compound, [Cu(C6F5COO)2(C4H4N2)]n, (I), the asymmetric unit contains one Cu(II) cation, two anionic pentafluorobenzoate ligands and one pyrazine ligand. Each Cu(II) centre is five-coordinated by three O atoms from three independent pentafluorobenzoate anions, as well as by two N atoms from two pyrazine ligands, giving rise to an approximately square-pyramidal coordination geometry. Adjacent Cu(II) cations are bridged by a pyrazine ligand and two pentafluorobenzoate anions to give a two-dimensional layer. The layers are stacked to generate a three-dimensional supramolecular architecture via strong intermolecular C-H···F-C interactions, as indicated by the F···H distance of 2.38 Å.

Tuning of valence States, bonding types, hierarchical structures, and physical properties in copper/halide/isonicotinate system

Seven cupric halide coordination polymers, namely [Cu5(OH)3Br3(ina)4] (1), [Cu5(OH)3Cl3(ina)4] (2), [Cu2(OH)Cl(ina)2] (3), [Cu3(OH)2Cl2(ina)2]·2H2O (4), [Cu3(OH)2Br2(ina)2]·2H2O (5), [Cu2Cl2(ina)2(H2O)2] (6), [Cu2Cl(ina)2(gca)(H2O)] (7), cupric complex templated cuprous halide [Cu(II)(Me-ina)2(H2O)][Cu(I)5Br7] (8), and organic templated cuprous halide Me2-ina[Cu2Br3] (9) (Hina = isonicotinic acid), were prepared from the starting materials of cupric halide and Hina via fine-tuning solvothermal reactions. According to valence states of copper, 1-7 are copper(II) complexes, 8 is a mixed-valent Cu(I,II) complex, while 9 is a Cu(I) compound. According to bonding types of halides, nine complexes can be classified as three types: complexes 1-3 include only normal X-Cu bond (X = halide); complexes 4-7 include normal X-Cu bond and X···Cu weak bond; complexes 8 and 9 include normal X-Cu bond and X···H-C halogen hydrogen bonds. Complexes 1 and 2 are isomorphic three-dimensional (3D) pcu topological metal organic frameworks (MOFs) with butterfly-like Cu4(μ3-OH)2X2 and steplike Cu6(μ3-OH)4 cores as nodes, showing strong ferromagnetic couplings. Complex 3 also is a pcu topological MOF with only butterfly-like Cu4(μ3-OH)2Cl2 clusters as nodes, presenting spin canting antiferromagnetic behavior. Isostructural 4 and 5 are Cu3(OH)2 clusters based two-dimensional (2D) (4,4) layers, which are extended into 3D eight-connected networks via weak Cu···X bonds, showing ferromagnetic coupling. Antiferromagnetic 6 is a simple one-dimensional coordination polymer, which is extended via weak Cu···Cl bonds into 3D (3,4)-connected networks. Paramagnetic 7 is a ladderlike polymer, which is extended into 2D (3,4)-connected layer via weak Cu···Cl bonds. The syntheses of polymeric cupric complexes 1-7 mainly result from differences in reactant ratio and pH value. Utilization of reducing methanol generated novel cubane-containing [Cu5Br7](2-) chain templated by paddlewheel-like [Cu(II)(Me-ina)2](2+) 8 and face-shared dimer-containing [Cu2Br3](-) chain templated by N-methylated and O-esterificated Me2-ina 9. Complex 9 exhibits a strong red emission and a weaker green emission upon excitation.

A cationic copper(i) iodide cluster MOF exhibiting unusual ligand assisted thermochromism

A cationic CuI cluster MOF 1, {Cu₆I₅[(NHAQ)₃PS]₂(OH)·3DMF·2.5MeOH}_n (AQ = 3-quinolinyl), was shown to exhibit an unusual thermochromic luminescent behaviour emitting a blue fluorescence at 298 K and a pale-orange phosphorescence at 77 K.

Charge-transfer metal–organic frameworks based on CuCN architecture units: crystal structures, luminescence properties and theoretical investigations

Four cuprous cyanide charge-transfer metal–organic frameworks have been fabricated via the synchronous redox and self-assembly reaction, and exhibit intense green luminescence properties and high thermal stabilities.

Cu(I), Co(II) and Fe(II) coordination polymers with pyrazine and benzoate as ligands. Spin crossover, spin canting and metamagnetism phenomena

The isolation and characterization of four coordination polymers obtained by direct reactions of metal ion salts of Cu(II), Co(II) and Fe(II) with pyrazine (pyz) and benzoic/benzoate (Bz) ligands under hydrothermal or hydrothermal microwave conditions are described. The use of copper(II) perchlorate as the starting salt allows us to obtain compounds in a selective way by changing the pH values giving rise to the formation of two 3D-coordination polymers: [Cu(pyz)2]ClO4·pyz (1) and [Cu2(pyz)4](ClO4)2·HBz·H2O (2). In both polymers, 4-connected Cu(I) uninodal coordination networks with significant structural differences between them, due to the templating effect of the solvation molecules and counterions, have been found. However, reactions carried out under similar conditions with MSO4 (M = Co and Fe) led to the isolation of two [M2(μ-Bz)2(μ-pyz)2(Bz)2]·(HBz) isostructural infinite 1D ladder chains (M = Co (3) and M = Fe (4)). These coordination polymers show a spin-canting antiferromagnetism and metamagnetism behaviour for Co(II) and HS ↔ HS/LS ↔ LS spin-crossover phenomena for Fe(II), respectively. The latter compound is the first example of a Fe(II)O4N2 coordination environment showing this phenomenon.