Comparison of two polymeric transition metal complexes with 1,4‐benzenedicarboxylate ions as bridging ligands, [Co(C8H4O4)(C12H8N2)(H2O)] and [Cu(C8H4O4)(C10H9N3)]·H2O

The title complexes, catena‐poly[[aqua(1,10‐phenanthroline‐κ²N,N′)­cobalt(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₈N₂)(H₂O)], (I), and catena‐poly[[[(di‐2‐pyridyl‐κN‐amine)copper(II)]‐μ‐benzene‐1,4‐di­carboxyl­ato‐κ⁴O¹,O^1′:O⁴,O^4′] hydrate], [Cu(C₈H₄O₄)(C₁₀H₉N₃)]·H₂O, (II), take the form of zigzag chains, with the 1,4‐benzene­di­carboxyl­ate ion acting as an amphimonodentate ligand in (I) and a bis‐bidentate ligand in (II). The Co^II ion in (I) is five‐coordinate and has a distorted trigonal–bipyramidal geometry. The Cu^II ion in (II) is in a very distorted octahedral 4+2 environment, with the octahedron elongated along the trans O—Cu—O bonds and with a trans O—Cu—O angle of only 137.22 (8)°.     

[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.     

RbCrIII(C2O4)2·2H2O,Cs2Mg(C2O4)2·4H2O and Rb2CuII(C2O4)2·2H2O: three new complex oxalate hydrates

Rubidium chromium(III) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­chromium(III)­rubidium(I)], [RbCr(C₂O₄)₂(H₂O)₂], (I), and dicaesium magnesium dioxalate tetrahydrate [tetra­aqua­bis(μ‐oxalato)­magnesium(II)­dicaesium(I)], [Cs₂Mg(C₂­O₄)₂(H₂O)₄], (II), have layered structures which are new among double‐metal oxalates. In (I), the Rb and Cr atoms lie on sites with imposed 2/m symmetry and the unique water molecule lies on a mirror plane; in (II), the Mg atom lies on a twofold axis. The two non‐equivalent Cr and Mg atoms both show octahedral coordination, with a mean Cr—O distance of 1.966 Å and a mean Mg—O distance of 2.066 Å. Dirubid­ium copper(II) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­copper(II)­dirubidium(I)], [Rb₂Cu(C₂O₄)₂(H₂O)₂], (III), is also layered and is isotypic with the previously described K₂‐ and (NH₄)₂Cu^II(C₂O₄)₂·2H₂O compounds. The two non‐equivalent Cu atoms lie on inversion centres and are both (4+2)‐coordinated. Hydro­gen bonds are medium‐strong to weak in the three compounds. The oxalate groups are slightly non‐planar only in the Cs–Mg compound, (II), and are more distinctly non‐planar in the K–Cu compound, (III).     

[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.     

The binary adduct of 3,6,9,16,19,22‐hexaazatricyclo[22.2.2.211,14]triaconta‐11,13,24,26(1),27,29‐hexaene and benzene‐1,2,4,5‐tetracarboxylic acid

The crystals of the title salt, 6,21‐di­aza‐3,9,18,24‐tetraazoniatri­cyclo­[22.2.2.2^11,14]­triaconta‐11,13,24,26(1),27,29‐hexaene benzene‐1,2,4,5‐tetra­carboxyl­ate(4?) hexahydrate, C₂₄H₄₂N₆⁴⁺·C₁₀H₂O₈^4?·6H₂O, are formed by the intermolecular interaction of a macrocyclic hex­amine with a mol­ecule of C₆H₂(COOH)₄ in aqueous solution. Both the cation and the anion are on inversion centres. Hydro­gen bonds are formed between the four ammonium cations in the hex­amine and the four carboxyl­ate anions in the aromatic acid. Stacks exist along the crystallographic a axis in the solid state. The water mol­ecules also take part in a hydrogen‐bonding network which joins these stacks together.     

Polymeric aqua­(μ4‐di­hydrogen benzene‐1,2,4,5‐tetra­carboxylato)(1,10‐phen­anthroline)cobalt(II)

In the title compound, poly[[aqua(1,10‐phenanthroline)­cobalt(II)]‐μ₄‐di­hydrogen benzene‐1,2,4,5‐tetra­carboxyl­ato], [Co(C₁₀H₄O₈)(C₁₂H₈N₂)(H₂O)]_n, each cobalt(II) cation has an octahedral geometry completed by one aqua O atom, three carboxy O atoms belonging to three H₂TCB²⁻ anions (H₂TCB²⁻ is di­hydrogen ­benzene‐1,2,4,5‐tetra­carboxyl­ate) and two N atoms from a 1,10‐phenanthroline mol­ecule. In the asymmetric unit, there are two half H₂TCB²⁻ anions lying about independent inversion centres. The bridging H₂TCB²⁻ anions have two coordination modes, viz.μ₂‐H₂TCB²⁻ and μ₄‐H₂TCB²⁻, resulting in a two‐dimensional coordination polymer. Furthermore, a three‐dimensional network is formed by O_carboxy⋯O_carboxy hydrogen‐bond interactions, with H⋯A distances in the range 1.69–1.82 Å, and O_carboxy⋯O_water interactions, with H⋯A distances in the range 1.91–1.94 Å.     

The first X‐ray structure of a hexa­ammine­cobalt(III) salt with two different complex chloro­cadmium anions: synthesis,characterization and crystal structure of [Co(NH3)6]4[CdCl6][CdCl4(SCN)(H2O)]2Cl2·2H2O

In the title complex salt, tetra­kis[hexa­ammine­cobalt(III)] hexa­chloro­cadmate(II) bis­[aqua­tetra­chloro­thio­cyanato­cad­mate(II)] dichloride dihydrate, the discrete ions, i.e. [Co(NH₃)₆]³⁺, Cl⁻, [CdCl₆]⁴⁻ (located on an inversion centre) and [CdCl₄(SCN)(H₂O)]³⁻, together with cocrystallized water mol­ecules, are assembled by means of a network of hydrogen‐bonding inter­actions. This is the first X‐ray structure determination of a hexa­amminecobalt(III) salt with two different complex chloro­cadmium anions.     

{[Ca5(C8H4O4)5(H2O)9]·8H2O}n: the first crystallographically characterized non‐transition metal salt of isophthalic acid

The reaction of CaCO₃ with isophthalic acid in water yields nona­aqua­penta‐μ‐isophthalato‐pentacalcium octahydrate, {[Ca₅(C₈H₄O₄)₅(H₂O)₉]·8H₂O}_n, a complex polymeric one‐dimensional column structure bearing metal–carboxyl­ate bonds and Ca‐bound terminal and bridging water mol­ecules, in addition to hydrogen‐bonded water mol­ecules of crystallization. The asymmetric unit comprises half of the formula unit, with one Ca²⁺ ion located on a twofold axis, and contains 16 unique strong O—H⋯O hydrogen bonds, some of which link the columns together.     

Comparison of conventional and synchrotron X‐ray structure deter­minations of the adduct 1,2,4,5‐tetrahydroxybenzene–2,5‐dihydroxy‐1,4‐benzoquinone (1/1) and a conventional X‐ray structure determination of 1,2,4,5‐tetrahydroxybenzene monohydrate

The X‐ray structure of 1,2,4,5‐tetra­hydroxy­benzene (benzene‐1,2,4,5‐tetrol) monohydrate, C₆H₆O₄·H₂O, (I), reveals columns of 1,2,4,5‐tetra­hydroxy­benzene parallel to the b axis that are separated by 3.364 (12) and 3.453 (11) Å. Molecules in adjacent columns are tilted relative to each other by 27.78 (8)°. Water mol­ecules fill the channels between the columns and are involved in hydrogen‐bonding interactions with the 1,2,4,5‐tetra­hydroxy­benzene mol­ecules. The crystal structure of the adduct 1,2,4,5‐tetra­hydroxy­benzene–2,5‐di­hydroxy‐1,4‐benzo­quinone (1/1), C₆H₆O₄·C₆H₄O₄, (II), reveals alternating mol­ecules of 1,2,4,5‐tetra­hydroxy­benzene and 2,5‐di­hydroxy‐1,4‐benzo­quinone (both lying on inversion centers), and a zigzag hydrogen‐bonded network connecting mol­ecules in three dimensions. For compound (II), the conventional X‐ray determination, (IIa), is in very good agreement with the synchrotron X‐ray determination, (IIb). When differences in data collection temperatures are taken into account, even the displacement parameters are in very good agreement.     

catena‐Poly[[(1,10‐phenanthroline‐κ2N,N′)copper(II)]‐μ‐(dihydrogen benzene‐1,2,4,5‐tetracarboxylato)‐κ2O1:O4]

In the title compound, [Cu(C₁₀H₄O₈)(C₁₂H₈N₂)]_n, the Cu^II cation has a four‐coordination environment completed by two N atoms from one 1,10‐phenanthroline (phen) ligand and two O atoms belonging to two di­hydrogen benzene‐1,2,4,5‐­tetra­carboxyl­ate anions (H₂TCB²⁻). There is a twofold axis passing through the Cu^II cation and the centre of the phen ligand. The [Cu(phen)]²⁺ moieties are bridged by H₂TCB²⁻ anions to form an infinite one‐dimensional coordination polymer with a zigzag chain structure along the c axis. A double‐chain structure is formed by hydrogen bonds between adjacent zigzag chains. Furthermore, there are π–π stacking inter­actions between the phen ligands, with an average distance of 3.64 Å, resulting in a two‐dimensional network structure.     

The titanium–thiolate complex [Li(C4H8O)4][Ti2(SC6H5)9]

In the title compound, tetrakis­(tetra­hydro­furan)­lithium(I) tri‐μ‐phenyl­thiol­ato‐bis­[tris­(phenyl­thiol­ato)­titanate(IV)], [Li(C₄H₈O)₄][Ti₂(C₆H₅S)₉], (I), the central structural motif of the [Ti₂(SC₆H₅)₉]^? anion features a face‐sharing bi‐octa­hedron. The charge is balanced with a [Li(C₄H₈O)₄]⁺ cation. The asymmetric unit contains Ti, Li and a heavily disordered tetra­hydro­furan mol­ecule on a threefold axis, and two terminal and a bridging thio­phenolate moiety and a slightly disordered tetra­hydro­furan mol­ecule on general positions.     

Cobalt(II) and nickel(II) complexes of quinoline‐2‐carboxyl­ate

The title complexes, trans‐di­aqua­bis­(quinoline‐2‐carboxyl­ato‐κ²N,O)­cobalt(II)–water–methanol (1/2/2), [Co(C₁₀H₆NO₂)₂(H₂O)₂]·2CH₄O·2H₂O, and trans‐di­aqua­bis­(quinoline‐2‐car­box­yl­ato‐κ²N,O)­nickel(II)–water–methanol (1/2/2), [Ni(C₁₀H₆NO₂)₂(H₂O)₂]·2CH₄O·2H₂O, are isomorphous and contain Co^II and Ni^II ions at centers of inversion. Both complexes have the same distorted octahedral coordination geometry, and each metal ion is coordinated by two quinoline N atoms, two carboxyl­ate O atoms and two water O atoms. The quinoline‐2‐carboxyl­ate ligands lie in trans positions with respect to one another, forming the equatorial plane, with the two water ligands occupying the axial positions. The complex mol­ecules are linked together by hydrogen bonding involving a series of ring patterns which include the uncoordinated water and methanol mol­ecules.     

Two isomorphous imidazole (Him) complexes: [MCl2(Him)2(H2O)2] (M = Co and Ni)

The structures of aqua­di­chloro­bis(1H‐imidazole)­cobalt(II), [CoCl₂(Him)₂(H₂O)₂] (Him is 1H‐imidazole, C₃H₄N₂), (I), and aqua­di­chloro­bis(1H‐imidazole)­nickel(II), [NiCl₂(Him)₂(H₂O)₂], (II), are isomorphous and consist of monomers with inversion symmetry. The three monodentate ligands (imidazole, chlorine and aqua), together with their symmetry equivalents, define almost perfect octahedra. Hydro­gen‐bonding interactions via the imidazole and aqua H atoms lead to a three‐dimensional network.     

An unusual P312 framework for the Ni(4,4′‐bipyridine)(H2O)4 chain

catena‐Poly[[[tetra­aqua­nickel(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′] thio­sulfate dihydrate], {[Ni(C₁₀H₈N₂)(H₂O)₄]S₂O₃·2H₂O}_n, (I), and catena‐poly[[[tetra­aqua­nickel(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′] sulfate methanol solvate monohydrate], {[Ni(C₁₀H₈N₂)(H₂O)₄]SO₄·CH₄O·H₂O}_n, (II), are built up of {[Ni(4,4′‐bipy)(H₂O)₄]²⁺}_n chains (4,4′‐bipy is 4,4′‐bipyridine) inter­woven in an unusual P3₁ fashion. Voids are filled by the corresponding counter‐anions and solvate mol­ecules, defining a complex three‐dimensional network surrounding them. In both structures, the cationic chains evolve around a set of twofold axes passing through the Ni^II ions and bis­ecting the aromatic amines through their N (and their opposite C) atoms.     

The sodium salt of a tris­(tridentate anion)­gadolinium(III) complex: penta­sodium bis­[chelidamato(3−)][chelidamato(2−)]­gadolinate(III) hexa­deca­hydrate

The sodium salt of a complex anion formed between gadolinium(III) and three variously deprotonated chelidamic acid (4‐hydroxy­pyridine‐2,6‐di­carboxyl­ic acid) ligand moi­eties, assigned as Na₅[Gd(C₇H₂NO₅)₂(C₇H₃NO₅)]·16H₂O, i.e. pentasodium (4‐hydroxy­pyridine‐2,6‐di­carboxyl­ate)­bis(4‐oxido­pyridine‐2,6‐di­carboxyl­ate)­gadolinium(III) hexadecahydrate, forms as colourless monoclinic crystals upon vapour diffusion of ethanol into its aqueous solution. The ligand moieties, assigned as two trianionic and one dianionic chelidamate species, are all tridentate in the complex anion of tricapped trigonal prismatic donor‐atom geometry. The geometry of the ligands and that of the primary coordination sphere is very similar to that of the analogous anionic tris­(ligand)–rare earth complexes of the pyridine‐2,6‐di­carboxyl­ate (dipicolinate) dianion.     

catena‐Poly­[bis­[(2,2‐bi­pyridine‐κ2N,N′)­copper(II)]‐μ4‐1,2,4,5‐benzene­tetra­carboxyl­ato‐κ4O1:O2:O3:O4]

In the title complex, [Cu₂(C₁₀H₂O₈)(C₁₀H₈N₂)₂]_n, the Cu^II cation has a four‐coordinated environment, completed by two carboxyl O atoms belonging to two 1,2,4,5‐benzene­tetra­carboxyl­ate anions (TCB⁴⁻) and two N atoms from one 2,2′‐bi­pyridine (2,2′‐bipy) ligand, forming a distorted square‐planar geometry. The [Cu(2,2′‐bipy)]²⁺ moieties are bridged by TCB⁴⁻ anions, which lie about inversion centres, forming an infinite one‐dimensional coordination polymer with a double‐chain structure along the a axis. A two‐dimensional network structure is formed via a face‐to‐face π–π interaction between the 2,2′‐bipy rings belonging to two adjacent double chains, at a distance of approximately 3.56 Å.     

Poly­[[di­aqua­tris(μ6‐benzene‐1,2,4,5‐tetra­carboxyl­ato)­tris(μ2‐4,4′‐bi­pyridine)­hexacopper(II)] dihydrate]

The hydro­thermal reaction of an aqueous solution of Cu(CH₃COO)₂·H₂O, 1,2,4,5‐benzene­tetra­carboxylic acid and 4,4′‐bi­pyridine gave rise to the interesting title three‐dimensional polymer {[Cu₆(btec)₃(4,4′‐bpy)₃(H₂O)₂]·2H₂O}_n (btec is 1,2,4,5‐benzene­tetra­carboxyl­ate, C₁₀H₂O₈⁴⁻, and 4,4′‐bpy is 4,4′‐bi­pyridine, C₁₀H₈N₂), in which each btec ligand links six copper(II) cations into a lamellar [Cu₆(btec)₃(H₂O)₂]_n sub­polymer framework. There are two distinct diamine units and two distinct carboxylate units, with one of each lying across an inversion centre.     

On the way to sol–gels: an analysis of the intra‐ and intermolecular hydrogen bonding in [Ba(OH)I(H2O)4]

We have been able, via a new synthetic route, to obtain a complete crystal structure of the title compound, tetra­aqua­barium hydro­xide iodide, [Ba(OH)I(H₂O)₄], for which the heavy atoms only were characterized by Kellersohn, ­Beckenkamp & Lutz [Z. Naturforsch. TeilB (1991), 46 , 1279–1286]. In the present results, the H‐atom positions could be located using X‐ray data collection at low temperature. A three‐dimensional network is built up via hydrogen bonds. It was also observed that the title compound undergoes hy­drolysis and might therefore be regarded as an intermediate in the formation of sol–gels, starting from BaI₂ and leading to [Ba(OH)₂(H₂O)_x].     

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.     

catena‐Poly[[copper(II)‐μ‐2‐[bis­(2‐pyridylmeth­yl)amino]butyrato‐κ4N,N′,N′′,O:κO′] perchlorate]

The copper(II) ion in the syn–anti carboxyl­ate‐bridged one‐dimensional zigzag chain title complex, {[Cu(C₁₆H₁₈N₃O₂)]ClO₄}_n, exhibits a distorted trigonal–bipyramidal environment. Two N atoms and one carboxyl­ate O atom of the ligand form the basal plane, while the axial positions are filled by an N atom of the ligand and one O atom belonging to the carboxyl­ate group of an adjacent mol­ecule. The crystal packing is enhanced by C—H⋯O(perchlorate) hydrogen bonds.