A redetermination of bis­(5,5′-diethyl­barbiturato)bis­(imidazole)cobalt(II)

The title complex, [Co(C8H12N2O3)2(C3H4N2)2], whose structure was first determined by Wang & Craven [(1971). J. Chem. Soc. D, pp. 290–291], has been redetermined with improved precision. A crystallographic twofold rotation axis passes through the Co atom, which is tetrahedrally coordinated by two N atoms from two barbital ligands and two N atoms from two imidazole ligands. The mol­ecules are self-assembled via inter­molecular N—H⋯O hydrogen-bonding inter­actions into a supra­molecular network

Aqua­bis(1H-imidazole-κN 3)bis­(4-methyl­benzoato)-κO;κO,O′-nickel(II)

In the mononuclear title compound, [Ni(C8H7O2)2(C3H4N2)2(H2O)], the NiII atom is coordinated by three carboxylate O atoms (from a bidentate 4-methyl­benzoate ligand and a monodentate 4-methyl­benzoate ligand), two N atoms (from two imidazole ligands) and a water mol­ecule in an octa­hedral geometry. Inter­molecular O—H⋯O hydrogen-bonding inter­actions lead to infinite chains, which are further self-assembled into a supra­molecular network through inter­molecular N—H⋯O hydrogen-bonding inter­actions and π–π stacking [centroid–centroid distance = 3.717 (2) Å]

Poly[[μ2-aqua-aqua­(μ3-3,5-dinitro­salicylato)barium(II)] monohydrate]

In the title coordination polymer, {[Ba(C7H2N2O7)(H2O)2]·H2O}n, the BaII atom is ten-coordinated by seven O atoms from four 3,5-dinitro­salicylatate ligands, two μ2-bridging aqua ligands and one water mol­ecule. The coordination mode is best described as a bicapped square-anti­prismatic geometry. The 3,5-dinitrosalicylatate ligands bridge three Ba atoms. Centrosymmetrically related dinuclear barium units, with a Ba⋯Ba separation of 4.767 (5) Å, form infinite chains, which are further self-assembled into a supra­molecular network through inter­molecular O—H⋯O hydrogen-bonding inter­actions between O atoms of 3,5-dinitro­salicylatate ligands and water mol­ecules

Diaqua­bis­(5-carb­oxy-2-propyl-1H-imidazole-4-carboxyl­ato-κ2 N 3,O 4)nickel(II) tetra­hydrate

In the title complex, [Ni(C8H9N2O4)2(H2O)2]·4H2O, the NiII ion is coordinated in a slightly distorted octa­hedral environment formed by two bis-chelating H2pimda (H3pimda is 2-propyl-1H-4,5-dicarb­oxy­lic acid) ligands and two coordinated water mol­ecules. In the crystal structure, a three-dimensional framework is formed by inter­molecular O—H⋯O and N—H⋯O hydrogen bonds involving the solvent water mol­ecules, coordinated water mol­ecules, carboxyl­ate O atoms and the protonated N atoms of the H2pimda ligands. The propyl groups of each H2pimda ligand are disordered over two sets of sites with refined occupancies of 0.50 (2):0.50 (2) and 0.762 (11):0.238 (11). In one water solvent mol­ecule, one of the H atoms was refined as disordered over two sites of equal occupancy

A Series of New Three-Dimensional d–f Heterometallic Coordination Polymers with Rare 10-Connected <b>bct</b> Net Topology Based on Planar Hexanuclear Heterometallic Second Building Units

A series of new three-dimensional (3D) d–f heterometallic coordination polymers, namely, [LnM­(μ₅-PyIDC)­(μ₂-INIC)­(μ₃-INIC)]·<i>x</i>H₂O [Ln = Sm, M = Co, <i>x</i> = 3 (<b>1</b>); Ln = Sm, M = Ni, <i>x</i> = 1 (<b>2</b>); Ln = Eu, M = Co, <i>x</i> = 3 (<b>3</b>); Ln = Eu, M = Cd, <i>x</i> = 3 (<b>4</b>); Ln = Eu, M = Zn, <i>x</i> = 3 (<b>5</b>); Ln = Gd, M = Co, <i>x</i> = 3 (<b>6</b>); Ln = Gd, M = Cd, <i>x</i> = 3 (<b>7</b>); Ln = Tb, M = Co, <i>x</i> = 3 (<b>8</b>); Ln = Tb, M = Cd, <i>x</i> = 2 (<b>9</b>); Ln = Tb, M = Zn, <i>x</i> = 3 (<b>10</b>); H₃PyIDC = 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid; HINIC = isonicotinic acid], have been successfully synthesized under hydrothermal conditions and structurally characterized. All the complexes are isostructural and exhibit novel 3D pillar-layered coordination frameworks constructed by the linkages of 2D heterometallic layers and INIC^– pillars. Topological analysis indicates that those complexes possess a rare uninodal 10-connected <b>bct</b> topology based on planar hexanuclear heterometallic [Ln₂M₄(PyIDC)₂] second building units. To the best of our knowledge, complexes <b>1</b>–<b>10</b> represent examples of 3D lanthanide–transition heterometal–organic coordination polymers with highly connected <b>bct</b> networks. Moreover, the luminescence properties of complexes <b>3</b>–<b>5</b> and <b>7</b>–<b>10</b> and the magnetic properties of <b>6</b>–<b>8</b> were also investigated

Assembly of Chiral/Achiral Coordination Polymers Based on 2-(Pyridine-3-yl)-1H-4,5-imidazoledicarboxylic Acid: Chirality Transfer between Chiral Two-Dimensional Networks Containing Helical Chains

Three kinds of new coordination polymers, [Mn­(μ₃-HPyIDC)­(H₂O)]_<i>n</i> (<b>1a</b> and <b>1b</b>), {[Cd₃(μ₄-PyIDC)₂(H₂O)₄]·H₂O}_<i>n</i> (<b>2</b>), and [Ca­(μ₄-HPyIDC)­(H₂O)]_<i>n</i> (<b>3a</b> and <b>3b</b>), were synthesized from the solvothermal reactions of 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H₃PyIDC) with the corresponding metal salts. Crystal structure analysis showed that all coordination polymers were based on an analogical chiral two-dimensional (2D) secondary building unit (SBU) containing helical chains. The chirality of the 2D SBU was transferred to neighboring 2D SBUs via hydrogen bonds and coordination bonds in <b>1</b> and <b>3</b>, respectively, resulting in two homochiral frameworks. When opposite chirality was transferred between neighboring 2D SBUs via Cd­(II) ions, an achiral framework was generated, resulting in 2D nets packed in alternating <i>P</i> and <i>M</i> chirality in compound <b>2</b>. Furthermore, compounds <b>1</b>, <b>2</b>, and <b>3</b> feature 2D (8²·10), 3D (6²·8²)­(6²·8²·10²), and <b>cds</b> network topologies, respectively. Circular dichroism (CD) measurements also confirmed that the resulting crystals of <b>1</b> and <b>3</b> are racemic mixtures. Compounds <b>2</b> and <b>3</b> showed strong fluorescent emissions at room temperature

Assembly of Chiral/Achiral Coordination Polymers Based on 2-(Pyridine-3-yl)-1H-4,5-imidazoledicarboxylic Acid: Chirality Transfer between Chiral Two-Dimensional Networks Containing Helical Chains

Three kinds of new coordination polymers, [Mn­(μ₃-HPyIDC)­(H₂O)]_<i>n</i> (<b>1a</b> and <b>1b</b>), {[Cd₃(μ₄-PyIDC)₂(H₂O)₄]·H₂O}_<i>n</i> (<b>2</b>), and [Ca­(μ₄-HPyIDC)­(H₂O)]_<i>n</i> (<b>3a</b> and <b>3b</b>), were synthesized from the solvothermal reactions of 2-(pyridine-3-yl)-1H-4,5-imidazoledicarboxylic acid (H₃PyIDC) with the corresponding metal salts. Crystal structure analysis showed that all coordination polymers were based on an analogical chiral two-dimensional (2D) secondary building unit (SBU) containing helical chains. The chirality of the 2D SBU was transferred to neighboring 2D SBUs via hydrogen bonds and coordination bonds in <b>1</b> and <b>3</b>, respectively, resulting in two homochiral frameworks. When opposite chirality was transferred between neighboring 2D SBUs via Cd­(II) ions, an achiral framework was generated, resulting in 2D nets packed in alternating <i>P</i> and <i>M</i> chirality in compound <b>2</b>. Furthermore, compounds <b>1</b>, <b>2</b>, and <b>3</b> feature 2D (8²·10), 3D (6²·8²)­(6²·8²·10²), and <b>cds</b> network topologies, respectively. Circular dichroism (CD) measurements also confirmed that the resulting crystals of <b>1</b> and <b>3</b> are racemic mixtures. Compounds <b>2</b> and <b>3</b> showed strong fluorescent emissions at room temperature

Construction of Ba(II) Coordination Polymers Based on Imidazole-Based Dicarboxylate Ligands: Structural Diversity Tuned by Alcohol Solvents

Four novel three-dimensional (3D) barium–organic coordination polymers formulated as [Ba­(μ₅-H₂hmIDC)­(μ₂-H₂O)]_<i>n</i> (<b>1</b>), [Ba­(μ₃-H₃hmIDC)₂(μ₁-H₂O)]_<i>n</i> (<b>2</b>), [Ba­(μ₅-H₂hmIDC)­(μ₂-O₂)_0.5]_<i>n</i> (<b>3</b>), and [Ba­(μ₃-H₃hmIDC)­(μ₄-H₃hmIDC)]_<i>n</i> (<b>4</b>) were synthesized under the solvothermal conditions of 2-(hydroxymethyl)-1<i>H</i>-imidazole-4,5-dicarboxylic acid (H₄hmIDC) with BaCl₂·2H₂O using a combination of water or dimethyl formamide (DMF) with various alcohol solvents (methanol, ethanol, <i>n</i>-propanol, isopropanol, and <i>n</i>-butanol). Complex <b>1</b> is a 3D framework based on two-dimensional secondary building units (SBUs) and μ₅-H₂hmIDC^2– pillars. This complex contains a unique <b>alb</b> network topology with the Schläfli symbol (4⁵·6)₂(4¹⁰·6¹⁴·8⁴). Complex <b>2</b> is a (3,10)-connected framework with binuclear [Ba₂(COO)₂] SBUs as 10-connected nodes and two types of μ₃-H₂hmIDC^2– ligands as 3-connected nodes. Complex <b>3</b> is a 3D framework formed with one-dimensional (1D) SBUs and μ₅-H₂hmIDC linkers, wherein the unprecedented oxygen molecules are coordinated using a linear-μ-η¹:η¹-peroxo fashion, showing (5,6)-connected network topology with the Schläfli symbol (4⁶·5³·6)­(4⁶·5⁴·6⁵). Complex <b>4</b> is a 3D framework based on 1D SBUs with μ₃-H₃hmIDC and μ₄-H₃hmIDC as linkers. This complex exhibits a trinodal (3,4,7)-connected 3D framework with the Schläfli symbol (4²·6)­(4³·6³)­(4⁸·6¹¹·8²). The results revealed that the alcohol solvent plays a subtle yet essential role in the crystallization and construction of Ba­(II)-organic coordination frameworks with diverse 3D structures, although these alcohol molecules do not appear in the frameworks

Construction of Ba(II) Coordination Polymers Based on Imidazole-Based Dicarboxylate Ligands: Structural Diversity Tuned by Alcohol Solvents

Four novel three-dimensional (3D) barium–organic coordination polymers formulated as [Ba­(μ₅-H₂hmIDC)­(μ₂-H₂O)]_<i>n</i> (<b>1</b>), [Ba­(μ₃-H₃hmIDC)₂(μ₁-H₂O)]_<i>n</i> (<b>2</b>), [Ba­(μ₅-H₂hmIDC)­(μ₂-O₂)_0.5]_<i>n</i> (<b>3</b>), and [Ba­(μ₃-H₃hmIDC)­(μ₄-H₃hmIDC)]_<i>n</i> (<b>4</b>) were synthesized under the solvothermal conditions of 2-(hydroxymethyl)-1<i>H</i>-imidazole-4,5-dicarboxylic acid (H₄hmIDC) with BaCl₂·2H₂O using a combination of water or dimethyl formamide (DMF) with various alcohol solvents (methanol, ethanol, <i>n</i>-propanol, isopropanol, and <i>n</i>-butanol). Complex <b>1</b> is a 3D framework based on two-dimensional secondary building units (SBUs) and μ₅-H₂hmIDC^2– pillars. This complex contains a unique <b>alb</b> network topology with the Schläfli symbol (4⁵·6)₂(4¹⁰·6¹⁴·8⁴). Complex <b>2</b> is a (3,10)-connected framework with binuclear [Ba₂(COO)₂] SBUs as 10-connected nodes and two types of μ₃-H₂hmIDC^2– ligands as 3-connected nodes. Complex <b>3</b> is a 3D framework formed with one-dimensional (1D) SBUs and μ₅-H₂hmIDC linkers, wherein the unprecedented oxygen molecules are coordinated using a linear-μ-η¹:η¹-peroxo fashion, showing (5,6)-connected network topology with the Schläfli symbol (4⁶·5³·6)­(4⁶·5⁴·6⁵). Complex <b>4</b> is a 3D framework based on 1D SBUs with μ₃-H₃hmIDC and μ₄-H₃hmIDC as linkers. This complex exhibits a trinodal (3,4,7)-connected 3D framework with the Schläfli symbol (4²·6)­(4³·6³)­(4⁸·6¹¹·8²). The results revealed that the alcohol solvent plays a subtle yet essential role in the crystallization and construction of Ba­(II)-organic coordination frameworks with diverse 3D structures, although these alcohol molecules do not appear in the frameworks