Cobalt(II) and nickel(II) complexes of isoquinoline‐1‐carboxylate

trans‐Di­aqua­bis­(iso­quinoline‐1‐carboxyl­ato‐κ²N,O)­cobalt(II) dihydrate, [Co(C₁₀H₆NO₂)₂(H₂O)₂]·2H₂O, and trans‐di­aqua­bis­(iso­quinoline‐1‐carboxyl­ato‐κ²N,O)­nickel(II) dihydrate, [Ni(C₁₀H₆NO₂)₂(H₂O)₂]·2H₂O, contain the same isoquinoline ligand, with both metal atoms residing on a centre of symmetry and having the same distorted octahedral coordination. In the former complex, the Co—O(water) bond length in the axial direction is 2.167 (2) Å, which is longer than the Co—O(carboxylate) and Co—N bond lengths in the equatorial plane [2.055 (2) and 2.096 (2) Å, respectively]. In the latter complex, the corresponding bond lengths for Ni—O(water), Ni—O(carboxylate) and Ni—N are 2.127 (2), 2.036 (2) and 2.039 (3) Å, respectively. Both crystals are stabilized by similar stacking interactions of the ligand, and also by hydrogen bonds between the hydrate and coordinated water molecules.     

Cobalt(II), nickel(II) and copper(II) complexes of iso­quinoline‐3‐carbox­ylate

The crystal structures of the title complexes, namely trans‐bis­(iso­quinoline‐3‐carboxyl­ato‐κ²N,O)­bis­(methanol‐κO)cobalt(II), [Co(C₁₀H₆NO₂)₂(CH₃OH)₂], and the corresponding nickel(II) and copper(II) complexes, [Ni(C₁₀H₆NO₂)₂(CH₃OH)₂] and [Cu(C₁₀H₆NO₂)₂(CH₃OH)₂], are isomorphous and contain metal ions at centres of inversion. The three compounds have the same distorted octahedral coordination geometry, and each metal ion is bonded by two quinoline N atoms, two carboxyl­ate O atoms and two methanol O atoms. Two iso­quinoline‐3‐carboxyl­ate ligands lie in trans positions, forming the equatorial plane, and the two methanol ligands occupy the axial positions. The complex mol­ecules are linked together by O—H⋯O hydrogen bonds between the methanol ligands and neighbouring carboxyl­ate groups.     

Bis(μ‐pyridine‐2,6‐carboxyl­ato‐O,N,O′:O)­bis­[tri­aqua­manganese(II)]–pyridine‐2,6‐di­carboxylic acid (1/2)

In the structure of the title compound, [Mn₂(C₇H₃NO₄)₂(H₂O)₆]·2C₇H₅NO₄, a centrosymmetric dinuclear complex, hexaa­aqua­bis­(pyri­dine‐2,6‐di­carboxyl­ato)­dimanganese(II) and free pyri­dine‐2,6‐di­carboxyl­ic acid are present in a 1:2 ratio. In the complex, each Mn²⁺ ion is coordinated by three O atoms and one N atom from the pyridine‐2,6‐di­carboxyl­ate ligands and by three water O atoms, resulting in a distorted pentagonal bipyramidal coordination. Within the centrosymmetric dinuclear complex, two Mn²⁺ ions are bridged by two carboxyl­ate O atoms. The crystal structure is stabilized by hydrogen bonds involving all the H atoms of the water ligands.     

A one‐dimensional zigzag coordination polymer of di­aqua­(pyridine‐2,3‐di­carboxyl­ato)­cobalt(II)

The asymmetric unit of the title one‐dimensional coordination polymer, catena‐poly­[[μ‐pyridine‐2,3‐di­carb­oxyl­ato‐1κO:2κ²N,O′‐bis­[di­aqua­cobalt(II)]]‐μ‐pyridine‐2,3‐di­carboxyl­ato‐1κ²N,O:2κO′:1′κO′], [Co(C₇H₃NO₄)(H₂O)₂]_n, is composed of a cobalt(II) ion, a pyridine‐2,3‐di­carboxyl­ate dianion and two water mol­ecules. The polymer has a zigzag structure consisting of a chain of edge‐fused rings, and the polymer chains are linked by O—H⃛O hydrogen bonds into a three‐dimensional framework.     

[Cu{C2(COO)2}(H2O)3]·H2O,the first copper complex of acetyl­ene­dicarboxyl­ic acid

In the title compound, catena‐poly­[[[tri­aqua­copper(II)]‐μ‐acetyl­enedi­carboxyl­ato‐κ²O:O′′] hydrate], {[Cu(C₄O₄)(H₂O)₃]·H₂O}_n, the Cu^II ion is coordinated by two monodentate carboxyl­ate groups in trans positions and three water mol­ecules, thus forming a fivefold coordination polyhedron that can be described as a distorted square pyramid. All atoms are located on general sites. The polyhedra are connected by bifunctional acetyl­ene­di­carboxyl­ate ligands, to form almost linear chains parallel to [001]. Hydro­gen bonds involving the non‐coordinated water mol­ecule connect these chains to form a three‐dimensional framework.     

Copper(II) and zinc(II) complexes of pyridine‐2,6‐di­carboxyl­ic acid

The title compounds, bis­(pyridine‐2,6‐di­carboxyl­ato‐N,O,O′)copper(II) monohydrate, [Cu(C₇H₄NO₄)₂]·H₂O, andbis(pyridine‐2,6‐dicarboxylato‐N,O,O′)zinc(II) trihydrate, [Zn(C₇H₄NO₄)₂]·3H₂O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl‐N atoms from the two terdentate ligand mol­ecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand mol­ecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand mol­ecules. Both crystal structures are stabilized by O—H?O intermolecular hydrogen bonds between the complex and the water mol­ecules.     

Bis(μ‐ethyl pyridine‐2,6‐di­carboxyl­ato)­bis­[di­aqua­chloro­cadmium(II)] dihydrate

The reaction of cadmium chloride with pyridine‐2,6‐di­carboxylic acid (PDA) and 98% H₂SO₄ in ethanol led to the formation of the title compound, bis­[μ‐6‐(ethoxy­carbonyl)­pyridine‐2‐carboxyl­ato]‐1:2κ⁴O⁶,N,O²:O²;1:2κ⁴O²:O²,N,O⁶‐bis­[di­aqua­chloro­cadmium(II)] dihydrate, [Cd₂(C₉H₈NO₄)₂Cl₂(H₂O)₄]·2H₂O. PDA is esterified to monoethyl ­pyridine‐2,6‐di­carboxyl­ate (MEPD) by the catalysis of H₂SO₄ during the reaction. The dinuclear Cd^II complex lies about an inversion centre and the unique Cd atom has a pentagonal–bipyramidal geometry. The two Cd atoms are bridged by two carboxyl­ate O atoms, forming a planar Cd₂O₂ unit. Stair‐like chains are formed via O—H⋯Cl hydrogen bonds and these are further arranged into two‐dimensional layers via hydrogen bonds involving solvate water mol­ecules.     

Calcium(II) meso‐2,3‐di­phenyl­succinate heptahydrate

The title compound, [Ca(C₁₆H₁₂O₄)(H₂O)₆]·H₂O, adopts a conformation about the central C—C bond that places the two carboxylate groups in an anti orientation. The crystal consists of layers of two‐dimensional arrays of 2,3‐di­phenyl­succinate dianions which are linked by bridging Ca²⁺ cations. The unit cell contains two Ca²⁺ cations in an unusual four‐membered Ca—O—Ca—O ring in which the bridging O atoms belong to water mol­ecules rather than carboxyl­ates, i.e. poly­[[[di‐μ‐aqua‐bis­[penta­aqua­calcium(II)]]‐μ‐(meso‐2,3‐di­phenyl­succinato‐O:O′)] succinate dihydrate].     

A novel copper(II) coordination polymer with 2,2′‐bipyridyl‐3,3′‐di­carboxylic acid

A novel copper(II) coordination polymer, poly­[[[aqua­copper(II)]‐μ₃‐2,2′‐bipyridyl‐3,3′‐di­carboxyl­ato‐κ⁴N,N′:O:O′] dihydrate], {[Cu(C₁₂H₆N₂O₄)(H₂O)]·2H₂O}_n, was obtained by the reaction of CuCl₂·2H₂O and 2,2′‐bipyridyl‐3,3′‐di­carboxylic acid (H₂L) in water. In the mol­ecule, each Cu^II atom is five‐coordinated and lies at the centre of a square‐pyramidal basal plane, bridged by three L ligands to form a two‐dimensional (4,4)‐network. Each L moiety acts as a bridging tetradentate ligand, coordinating to three Cu^II atoms through its two aromatic N atoms and two O atoms of the two carboxyl groups. The two‐dimensional square‐grid sheets superimpose in an off‐set fashion through the inorganic water layer.     

5‐n‐Butylpyridine‐2‐carboxylate–copper(II) and –iron(III) complexes

In trans‐bis(5‐n‐butyl­pyridine‐2‐carboxyl­ato‐κ²N,O)­bis­(methanol‐κO)copper(II), [Cu(C₁₀H₁₂NO₂)₂(CH₄O)₂], the Cu atom lies on a centre of symmetry and has a distorted octahedral coordination. The Cu—O(methanol) bond length in the axial direction is 2.596 (3) Å, which is much longer than the Cu—­O(carboxylate) and Cu—N distances in the equatorial plane [1.952 (2) and 1.977 (2) Å, respectively]. In mer‐tris(5‐n‐bu­tyl­pyridine‐2‐carboxyl­ato‐κ²N,O)­iron(III), [Fe(C₁₀H₁₂NO₂)₃], the Fe atom also has a distorted octahedral geometry, with Fe—O and Fe—N bond‐length ranges of 1.949 (4)–1.970 (4) and 2.116 (5)–2.161 (5) Å, respectively. Both crystals are stabilized by stacking interactions of the 5‐n‐butyl­pyridine‐2‐carboxyl­ate ligand, although hydrogen bonds also contribute to the stabilization of the copper(II) complex.     

Aqua(benzene‐1,3‐dicarboxylato)zinc(II)

The title compound, poly­[[aqua­zinc(II)]‐μ‐benzene‐1,3‐di­carboxyl­ato‐O¹:O^1′:O²], [Zn(C₈H₄O₄)(H₂O)]_n, forms a metal–organic coordination network that consists of tetrahedral Zn atoms bonded to one water mol­ecule and three carboxyl­ate groups. Isophthalate groups bridge the four‐coordinate Zn centers to generate two‐dimensional architectures in the ac plane. These planar zinc isophthalate motifs are linked by infinite C=O?H—O—H interactions along the a axis to form a chiral framework. The observed polar structural pattern originates due to the distorted tetrahedral Zn centers [O—Zn—O 100.7 (2)–136.0 (1)°] and the alignment of the water mol­ecules. Bridging isophthalate groups align to form approximate centrosymmetric motifs.     

catena‐Poly­[[trans‐bis­(ethane‐1,2‐di­amine‐κ2N,N′)copper(II)]‐μ‐di­thion­ato‐κ2O:O′] and trans‐di­aqua­bis­(propane‐1,3‐di­amine‐κ2N,N′)copper(II) di­thionate

In title an­hydro­us catena‐poly­[[trans‐bis­(ethane‐1,2‐di­amine‐κ²N,N′)copper(II)]‐μ‐di­thionato‐κ²O:O′], [Cu(S₂O₆)(C₂H₈N₂)₂]_n or [{H₂N(CH₂)₂NH₂}₂Cu(O·O₂SSO₂·O)]_∞, successive Cu atoms are bridged by a single doubly charged di­thionate group, forming a one‐dimensional polymer with inversion centres at the metal atoms and the mid‐point of the S—S bond [Cu—O = 2.5744 (15) Å]. In title (hydrated) trans‐di­aqua­bis­(propane‐1,3‐di­amine‐κ²N,N′)copper(II) di­thionate, [Cu(C₃H₁₀N₂)₂(H₂O)₂](S₂O₆) or [{H₂N(CH₂)₃NH₂}₂Cu(OH₂)₂](S₂O₆), both ions have imposed 2/m symmetry. The `axial' anion components are displaced by a pair of water ligands [Cu—O = 2.439 (3) Å], the shorter Cu—O distance being compensated by the lengthened Cu—N distance [2.0443 (18), cf. 2.0100 (13) and 2.0122 (16) Å].     

Aqua(dipicolinato‐κ3O2,N,O6)(1,10‐phenanthroline‐κ2N,N′)manganese(II) monohydrate

In the title compound [systematic name: aqua(1,10‐phenanthroline‐κ²N,N′)(pyridine‐2,6‐di­carboxyl­ato‐κ³O²,N,O⁶)manganese(II) monohydrate, [Mn(C₇H₃NO₄)(C₁₂H₈N₂)(H₂O)]·H₂O, the manganese(II) centre is surrounded by one bidentate phenanthroline ligand [Mn—N = 2.248 (3) and 2.278 (3) Å], one tridentate dipicolinate ligand [Mn—N = 2.179 (3) Å, and Mn—O = 2.237 (2) and 2.266 (2) Å] and one water mol­ecule [Mn—O = 2.117 (3) Å], and it exhibits a strongly distorted octahedral geometry, with trans angles ranging from 144.12 (9) to 158.88 (11)°. Extensive intermolecular hydrogen‐bonding interactions involving coordinated and uncoordinated water mol­ecules and the carboxyl O atoms of the dipicolinate ligand, as well as a stacking interaction involving the phenanthroline rings, are observed in the crystal structure.     

trans‐[N,N′‐Bis­(salicyl­idene)­cyclo­hexane‐1,2‐diaminato]­nickel(II)–chloro­form (1/1)

In the title complex, trans‐{2,2′‐[cyclo­hexane‐1,2‐diyl­bis­(ni­t­rilo­methyl­idyne)]­di­phenol­ato‐κ⁴O,N,N′,O′}­nickel(II)–chloro­form (1/1), [Ni(C₂₀H₂₀N₂O₂)]·CHCl₃, the Ni atom has a square‐planar geometry, slightly tetrahedrally distorted. The Ni—N and Ni—O bonding distances are within the expected ranges for Ni–Schiff base derivatives. The di­imine bridge has a gauche conformation with the cyclo­hexyl ring almost coplanar with the NiN₂O₂ plane. The complex mol­ecules pack in dimers with an Ni?Ni distance of 3.59 (1) Å and form a three‐dimensional structure displaying a herring‐bone configuration. Channels are occupied by solvent mol­ecules, which are involved in C—H?O hydrogen bonds with the ligand O atoms.     

trans‐Diaquabis(1H‐imidazole‐4,5‐di­carboxyl­ate‐κ2N3,O4)­manganese(II)

In the title compound, [Mn(C₅H₃N₂O₄)₂(H₂O)₂], the Mn^II atom lies on an inversion centre, is trans‐coordinated by two N,O‐bidentate 1H‐imidazole‐4,5‐di­carboxyl­ate monoanionic ligands [Mn—O = 2.202 (3) Å and Mn—N = 2.201 (4) Å] and two water mol­ecules [Mn—O = 2.197 (4) Å], and exhibits a distorted octahedral geometry, with adjacent cis angles of 76.45 (13), 86.09 (13) and 89.20 (13)°. The complete solid‐state structure can be described as a three‐dimensional supramol­ecular framework, stabilized by extensive hydrogen‐bonding interactions involving the coordinated water mol­ecules, the carboxy O atoms and the protonated imidazole N atoms of the imidazole‐4,5‐di­carboxyl­ate ligands.     

[Cd{C2(COO)2}(H2O)3]·H2O,the first cadmium salt of acetylenedicarboxylic acid

In catena‐poly­[[[tri­aqua­cadmium(II)]‐μ‐acetyl­enedi­carboxyl­ato‐κ⁴O,O′:O′′,O′′′] hydrate], {[Cd(C₄O₄)(H₂O)₃]·­H₂O}_n, the Cd^II atom is coordinated by two bidentate carboxyl­ate groups and three water mol­ecules, thus forming a sevenfold coordination polyhedron with all atoms located on general sites. These polyhedra are connected by the bifunctional acetyl­enedi­carboxyl­ate ligands, forming zigzag chains running parallel to [120]. Hydro­gen bonds, which involve the non‐coordinated water mol­ecule, connect these chains to form a three‐dimensional framework.     

8‐Hydroxyquinaldinic acid and its nickel(II) complex

The molecules of 8‐hydroxy­quinolinium‐2‐carboxyl­ate, C₁₀H₇NO₃, have a planar structure, in which the carboxyl group is ionized and the ring N atom is protonated. The derived nickel(II) complex, bis(8‐hydroxy­quinoline‐2‐carboxyl­ato‐κ³O²,N,O⁸)­nickel(II) trihydrate, [Ni(C₁₀H₆NO₃)₂]·3H₂O, contains an octahedral central Ni^II ion coordinated by the hydroxyl O atom, the ring N atom and the carboxyl­ate O atom of each of the two tridentate ligands, with a perpendicular orientation of the quinoline rings.     

Tetrakis[(4‐aminopyridinio)acetato‐κO]diaquamanganese(II) diper­chlorate

In the centrosymmetric title complex, [Mn(C₇H₈N₂O₂)₄(H₂O)₂](ClO₄)₂, the Mn^II ion is in an octahedral environment, with the equatorial plane being defined by the O atoms of four monodentate carboxyl­ate groups, and the octahedron being completed by two trans‐coordinated water mol­ecules. There are intramolecular hydrogen bonds between the coordinated water mol­ecules and the non‐coordinated O atoms of the carboxyl­ate groups. Hydrogen bonds between the amino groups and the carboxyl­ate groups of neighbouring mol­ecules generate a layered hydrogen‐bonded network.     

trans‐μ‐Oxamido‐N,N′‐diethano­ato‐bis­[di­aqua­copper(II)] dihydrate

The title complex, trans‐{μ‐2,2′‐[(1,2‐dioxoethane‐1,2‐diyl)­diimino]­diethano­ato(4−)}bis­[di­aqua­copper(II)] dihydrate, [Cu₂(C₆H₄N₂O₆)(H₂O)₄]·2H₂O, with a three‐dimensional framework, displays a square‐pyramidal coordination geometry. The structure consists of a neutral centrosymmetric binuclear unit in which the ox­amide ligand has a trans geometry, is fully deprotonated and acts in a bis‐tridentate fashion.     

Diaquabis(1,3‐propanediamine‐κ2N,N′)nickel(II) bis(sulfanilate)

The title compound, [Ni(C₃H₁₀N₂)₂(H₂O)₂](C₆H₆NO₃S)₂, contains alternating layers of sulfanilate anions and di­aqua­bis(1,3‐propane­di­amine)­nickel(II) cations. The Ni atom lies on an inversion centre and is hexacoordinated by the 1,3‐propane­di­amine ligands, which function as N,N′‐bidentate ligands, and the water mol­ecules, which are in a trans arrangement. The sulfanilate anions are arranged in layers, with the sulfonate and amine groups directed towards opposite sides of the layer. The structure is stabilized by a network of hydrogen bonding between the O and N atoms of the sulfanilate anions, the water mol­ecules, and the N atoms of the 1,3‐propane­di­amine ligands.