An ice‐like water hexamer with symmetry in the hydrogen‐bonded structure of 2,3,5,6‐tetrafluoro‐1,4‐bis(imidazol‐1‐ylmethyl)benzene dihydrate

An ice‐like hexameric water cluster, stabilized by the flexible bis‐imidazolyl compound 2,3,5,6‐tetrafluoro‐1,4‐bis(imidazol‐1‐ylmethyl)benzene (Fbix), is found in the trigonal R crystal structure of the title compound, C₁₄H₁₀F₄N₄·2H₂O or Fbix·2H₂O. The Fbix molecule lies about an inversion centre with one water molecule in the asymmetric unit in a general position. A cyclic chair‐like hexameric water cluster with symmetry is generated with a hydrogen‐bonded O...O distance within the hexamer of 2.786 (3) Å. The Fbix molecule adopts a trans conformation, where the imidazole ring makes a dihedral angle of 70.24 (11)° with the central tetrafluorinated aromatic ring. Each water hexamer is connected by six Fbix molecules through intermolecular O—H...N hydrogen bonds [N...O = 2.868 (3) Å] to yield a three‐dimensional supramolecular network with primitive cubic (pcu) topology. Large voids in each single pcu network lead to fourfold interpenetrated aggregates of Fbix·2H₂O.     

A three‐dimensional hydrogen‐bonded network in bis(4‐hydroxyanilinium) selenate(VI) dihydrate

The title compound, 2C₆H₈NO⁺·SeO₄²⁻·2H₂O, contains 4‐hydroxyanilinium cations, selenate(VI) anions and water molecules. One of the two independent cations is nearly planar (excluding the ammonium H atoms), while the other is markedly nonplanar, with the hydroxy and ammonium groups displaced from the plane of the benzene ring. This results from the antiparallel orientation of the cations, which interact through oppositely polarized ammonium and hydroxy groups. Ionic and hydrogen‐bonding interactions join the oppositely charged units into a three‐dimensional network. This work demonstrates the usefulness of 4‐aminophenol in the crystal engineering of organic–inorganic hybrid compounds.     

Three‐dimensional hydrogen‐bonded framework structures in flunarizinium nicotinate and flunarizinediium bis(4‐toluenesulfonate) dihydrate

The structures of two salts of flunarizine, namely 1‐bis[(4‐fluorophenyl)methyl]‐4‐[(2E)‐3‐phenylprop‐2‐en‐1‐yl]piperazine, C₂₆H₂₆F₂N₂, are reported. In flunarizinium nicotinate {systematic name: 4‐bis[(4‐fluorophenyl)methyl]‐1‐[(2E)‐3‐phenylprop‐2‐en‐1‐yl]piperazin‐1‐ium pyridine‐3‐carboxylate}, C₂₆H₂₇F₂N₂⁺·C₆H₄NO₂⁻, (I), the two ionic components are linked by a short charge‐assisted N—H...O hydrogen bond. The ion pairs are linked into a three‐dimensional framework structure by three independent C—H...O hydrogen bonds, augmented by C—H...π(arene) hydrogen bonds and an aromatic π–π stacking interaction. In flunarizinediium bis(4‐toluenesulfonate) dihydrate {systematic name: 1‐[bis(4‐fluorophenyl)methyl]‐4‐[(2E)‐3‐phenylprop‐2‐en‐1‐yl]piperazine‐1,4‐diium bis(4‐methylbenzenesulfonate) dihydrate}, C₂₆H₂₈F₂N₂²⁺·2C₇H₇O₃S⁻·2H₂O, (II), one of the anions is disordered over two sites with occupancies of 0.832 (6) and 0.168 (6). The five independent components are linked into ribbons by two independent N—H...O hydrogen bonds and four independent O—H...O hydrogen bonds, and these ribbons are linked to form a three‐dimensional framework by two independent C—H...O hydrogen bonds, but C—H...π(arene) hydrogen bonds and aromatic π–π stacking interactions are absent from the structure of (II). Comparisons are made with some related structures.     

A novel parallel interpenetrating two‐dimensional (4,4) network: poly[[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene](μ2‐naphthalene‐1,4‐dicarboxylato)zinc(II)]

In the title coordination compound, [Zn(C₁₂H₆O₄)(C₁₄H₁₄N₄)]_n, the two Zn^II centers exhibit different coordination environments. One Zn^II center is four‐coordinated in a distorted tetrahedral environment surrounded by two carboxylate O atoms from two different naphthalene‐1,4‐dicarboxylate (1,4‐ndc) anions and two N atoms from two distinct 1,4‐bis(imidazol‐1‐ylmethyl)benzene (1,4‐bix) ligands. The coordination of the second Zn^II center comprises two N atoms from two different 1,4‐bix ligands and three carboxylate O atoms from two different 1,4‐ndc ligands in a highly distorted square‐pyramidal environment. The 1,4‐bix ligand and the 1,4‐ndc anion link adjacent Zn^II centers into a two‐dimensional four‐connected (4,4) network. The two (4,4) networks are interpenetrated in a parallel mode.     

A supramolecular hydrogen‐bonded complex between 1,3,5‐tris(diisobutylhydroxysilyl)benzene and trans‐bis(4‐pyridyl)ethylene

The trisilanol 1,3,5‐(HOi‐Bu₂Si)₃C₆H₃ ( 7 ), prepared in three steps from 1,3,5‐tribromobenzene via the intermediates 1,3,5‐(Hi‐Bu₂Si)₃C₆H₃ ( 8 ) and 1,3,5‐(Cli‐Bu₂Si)₃C₆H₃ ( 9 ) forms an equimolar complex with trans‐bis(4‐pyridyl)ethylene (bpe), 7 ·bpe, whose structure was investigated by X‐ray crystallography. The hydrogen‐bonded network features a number of SiO? H(H)Si and SiO? H hydrogen bridges. Evidence was found for cooperative strengthening within the sequential hydrogen bonds. Copyright © 2007 John Wiley & Sons, Ltd.     

Poly[[sesqui[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene‐κ2N:N′](carbonato‐κ2O,O′)copper(II)] 1,4‐bis(imidazol‐1‐ylmethyl)benzene hemisolvate pentahydrate]

The asymmetric unit of the title compound, {[Cu(CO₃)(C₁₄H₁₄N₄)_1.5]·0.5C₁₄H₁₄N₄·5H₂O}_n, contains one Cu^II cation in a slightly distorted square‐pyramidal coordination environment, one CO₃²⁻ anion, one full and two half 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligands, one half‐molecule of which is uncoordinated, and five uncoordinated water molecules. One of the coordinated bix ligands and the uncoordinated bix molecule are situated about centers of symmetry, located at the centers of the benzene rings. The coordinated bix ligands link the copper(II) ions into a [Cu(bix)_1.5]_n molecular ladder. These molecular ladders do not form interpenetrated ladders but are arranged in an ABAB parallel terrace, i.e. with the ladders arranged one above another, with sequence A translated with respect to B by 8 Å. To best of our knowledge, this arrangement has not been observed in any of the molecular ladder frameworks synthesized to date. The coordination environment of the Cu^II atom is completed by two O atoms of the CO₃²⁻ anion. The framework is further strengthened by extensive O—H...O and O—H...N hydrogen bonds involving the water molecules, the O atoms of the CO₃²⁻ anion and the N atoms of the bix ligands. This study describes the first example of a molecular ladder coordination polymer based on bix and therefore demonstrates further the usefulness of bix as a versatile multidentate ligand for constructing coordination polymers with interesting architectures.     

Poly[(μ4‐biphenyl‐3,3′,4,4′‐tetracarboxylato)bis[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene]dicobalt(II)]

The asymmetric unit of the title two‐dimensional coordination polymer, [Co₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]_n, contains one Co²⁺ ion, half of a biphenyl‐3,3′,4,4′‐tetracarboxylate (bptc) anion lying about an inversion centre and one 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligand. The Co^II atom is coordinated by three carboxylate O atoms from two different bptc ligands and two N atoms from two bix ligands constructing a distorted square pyramid. Each Co²⁺ ion is interlinked by two bptc anions, while each bptc anion coordinates to four Co atoms as a hexadentate ligand so that four Co^II atoms and four bptc anions afford a larger 38‐membered ring. These inorganic rings are further extended into a two‐dimensional undulated network in the (10) plane. Two Co^II atoms in adjacent 38‐membered rings are joined together by pairs of bix ligands forming a 26‐membered [Co₂(bix)₂] ring that is penetrated by a bptc anion; these components share a common inversion centre.     

Synthesis,structure, thermostability and luminescence properties of ZnII and CdII coordination polymers based on dimethysuccinate and flexible 1,4‐bis(imidazol‐1‐ylmethyl)benzene ligands

The design and synthesis of functional coordination polymers is motivated not only by their structural beauty but also by their potential applications. Zn^II and Cd^II coordination polymers are promising candidates for producing photoactive materials because these d¹⁰ metal ions not only possess a variety of coordination numbers and geometries, but also exhibit luminescence properties when bound to functional ligands. It is difficult to predict the final structure of such polymers because the assembly process is influenced by many subtle factors. Bis(imidazol‐1‐yl)‐substituted alkane/benzene molecules are good bridging ligands because their flexibility allows them to bend and rotate when they coordinate to metal centres. Two new Zn^II and Cd^II coordination polymers based on mixed ligands, namely, poly[[μ₂‐1,4‐bis(imidazol‐1‐ylmethyl)benzene‐κ²N³:N^3′]bis(μ₃‐2,2‐dimethylbutanoato‐κ³O¹:O⁴:O^4′)dizinc(II)], [Zn₂(C₆H₈O₄)₂(C₁₄H₁₄N₄)]_n, and poly[[μ₂‐1,4‐bis(imidazol‐1‐ylmethyl)benzene‐κ²N³:N^3′]bis(μ₃‐2,2‐dimethylbutanoato‐κ⁵O¹,O^1′:O⁴,O^4′:O⁴)dicadmium(II)], [Cd₂(C₆H₈O₄)₂(C₁₄H₁₄N₄)]_n, have been synthesized under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction, elemental analysis, IR spectroscopy and thermogravimetric analysis. Both complexes crystallize in the monoclinic space group C2/c with similar unit‐cell parameters and feature two‐dimensional structures formed by the interconnection of S‐shaped Zn(Cd)–2,2‐dimethylsuccinate chains with 1,4‐bis(imidazol‐1‐ylmethyl)benzene bridges. However, the Cd^II and Zn^II centres have different coordination numbers and the 2,2‐dimethylsuccinate ligands display different coordination modes. Both complexes exhibit a blue photoluminescence in the solid state at room temperature.     

A novel two‐dimensional nickel(II) coordination polymer with 1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene and azide ligands

The coordination geometry of the Ni^II atom in the title complex, poly[diazidobis[μ‐1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene‐κ²N⁴:N^4′]nickel(II)], [Ni(N₃)₂(C₁₂H₁₂N₆)₂]_n, is a distorted octahedron, in which the Ni^II atom lies on an inversion centre and is coordinated by four N atoms from the triazole rings of two symmetry‐related pairs of 1,4‐bis(1,2,4‐triazol‐1‐ylmethyl)benzene (bbtz) ligands and two N atoms from two symmetry‐related monodentate azide ligands. The Ni^II atoms are bridged by four bbtz ligands to form a two‐dimensional (4,4)‐network.     

Synthesis,crystal structure and magnetic property of a two‐dimensional herringbone‐like network with praseodymium(III) nitrate and 1‐bromo‐ 3,5‐bis(imidazol‐1‐ylmethyl)benzene (bib)

A new complex [Pr(bib)₂(NO₃)₃] ( 1 ) was synthesized by reaction of bidentate imidazole‐containing ligand 1‐bromo‐3,5‐bis(imidazol‐1‐ylmethyl)benzene (bib) with Pr(NO₃)·6H₂O and characterized by X‐ray crystallography. Complex 1 has a two‐dimensional herringbone‐like structure with the ligand bib serving as a bridging ligand using its two imidazolyl nitrogen atoms. Ligand bib adopts cis and trans two different conformations, and the Pr(III) atoms are bridged by bib in two different ways. Thermogravimetric analysis for complex 1 was carried out and the result shows that the complex is stable up to 180 °C. Variable‐temperature magnetic susceptibility of complex 1 was measured between 1.8 and 300 K and the result shows that the χ_MT value decreases continuously over the whole temperature range. Copyright © 2005 John Wiley & Sons, Ltd.     

Melaminium bis(4‐hydroxybenzenesulfonate) dihydrate

The crystals of a new melaminium salt, 2,4,6‐tri­amino‐1,3,5‐triazine‐1,3‐diium bis(4‐hydroxy­benzene­sulfonate) dihydrate, C₃H₈N₆²⁺·2C₆H₅O₄S^?·2H₂O, are built up from doubly proton­ated melaminium(2+) residues, dissociated p‐phenol­sulfonate anions and water mol­ecules. The doubly protonated melaminium dication lies on a twofold axis. The hydroxyl group of the p‐hydroxybenzenesulfonate residue is roughly coplanar with the phenyl ring [dihedral angle 13 (2)°]. A combination of ionic and donor–acceptor hydrogen‐bond interactions link the melaminium and p‐hydroxybenzenesulfonate residues and the water mol­ecules to form a three‐dimensional network.     

Assembly of a two‐dimensional layer structure with 1,4‐bis(1H‐benzimidazol‐1‐ylmethyl)benzene dihydrate via hydrogen bonds and π–π interactions

In the title compound, C₂₂H₁₈N₄·2H₂O, the organic fragment lies across a centre of inversion in the P2₁/n space group. The water molecules form C(2)‐type hydrogen‐bonded chains which are linked to the 1,4‐bis(1H‐benzimidazol‐1‐ylmethyl)benzene molecules through O—H...N hydrogen bonds, forming sheets reinforced by π–π stacking interactions between the aromatic rings within the layers.     

Poly[[(μ2‐biphenyl‐2,4′‐dicarboxylato)[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene]cadmium(II)] 0.15‐hydrate]

The asymmetric unit of the title two‐dimensional coordination polymer, {[Cd(C₁₄H₈O₄)(C₁₄H₁₄N₄)]·0.15H₂O}_n, is composed of one Cd^II cation, one biphenyl‐2,4′‐dicarboxylate (bpdc) anion, one 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligand and 0.15 solvent water molecules. The coordination environment of the Cd^II cation is defined by four carboxylate O atoms from two different bpdc anions in a chelating mode and two N atoms from two distinct bix ligands, constructing a distorted trigonal prism polyhedron. Two inversion‐related Cd^II cations are bridged together by two positionally disordered bpdc anions, forming a 22‐membered ring with a Cd...Cd distance of 9.1966 (9) Å. These rings are then further linked by two bix ligands, extending into a two‐dimensional layer along (102) with 6³ topology.     

Hydrogen‐bonded frameworks of bis(2‐carboxypyridinium) hexafluorosilicate and bis(2‐carboxyquinolinium) hexafluorosilicate dihydrate

In bis(2‐carboxypyridinium) hexafluorosilicate, 2C₆H₆NO₂⁺·SiF₆²⁻, (I), and bis(2‐carboxyquinolinium) hexafluorosilicate dihydrate, 2C₁₀H₈NO₂⁺·SiF₆²⁻·2H₂O, (II), the Si atoms of the anions reside on crystallographic centres of inversion. Primary inter‐ion interactions in (I) occur via strong N—H...F and O—H...F hydrogen bonds, generating corrugated layers incorporating [SiF₆]²⁻ anions as four‐connected net nodes and organic cations as simple links in between. In (II), a set of strong N—H...F, O—H...O and O—H...F hydrogen bonds, involving water molecules, gives a three‐dimensional heterocoordinated rutile‐like framework that integrates [SiF₆]²⁻ anions as six‐connected and water molecules as three‐connected nodes. The carboxyl groups of the cation are hydrogen bonded to the water molecule [O...O = 2.5533 (13) Å], while the N—H group supports direct bonding to the anion [N...F = 2.7061 (12) Å].     

Tuning Cadmium Coordination Architectures by Phenylenediacetate Position Isomers and 1,4‐Bis(benzimidazol‐1‐ylmethyl)benzene

Three position isomers 1,2‐, 1,3‐, 1,4‐phenylenediacetate and 1,4‐bis(benzimidazol‐1‐ylmethyl)benzene (bmb) were used to assembly cadmium(II) coordination polymers, [Cd(bmb)(1,2‐phda)]_n ( 1 ), {Cd(bmb)(1,3‐phda)] · 0.5(bmb)}_n ( 2 ), and [Cd(bmb)_0.5(1,4‐phda)]_n ( 3 ), which are characterized by elemental analyses, infrared spectra (IR), thermogravimetric analysis (TGA) and single‐crystal X‐ray diffraction. Single crystal structure analysis shows that complex 1 is a two‐dimensional wave‐like layer network. Complex 2 features a (3,5)‐connected three‐dimensional frameworks with (4².6)(4².6⁵.8³) topology, whereas complex 3 shows a (4,4)‐connected three‐dimensional (4.6⁴.7)(4².6².8²) topology. The structural versatility reveals that a significant structure‐directing effect of the position of the acetate groups during self‐assembly of these coordination polymers. Moreover, luminescent properties and thermal stabilities of three complexes were discussed in detail.     

Four Complexes with the Rigid Ligand 1,4‐Bis(1H‐imidazol‐4‐yl)benzene and Varied Carboxylate Ligands

Four metal‐organic coordination polymers [Co₂(L)₃(nipa)₂]·6H₂O ( 1 ), [Cd(L)(nipa)]·3H₂O ( 2 ), [Co(L) (Hoxba)₂] ( 3 ) and [Ni₂(L)₂(oxba)₂(H₂O)]·1.5L·3H₂O ( 4 ) were synthesized by reactions of the corresponding metal(II) salts with the rigid ligand 1,4‐bis(1H‐imidazol‐4‐yl)benzene (L) and different derivatives of 5‐nitroisophthalic acid (H₂nipa) and 4,4′‐oxybis(benzoic acid) (H₂oxba), respectively. The structures of the complexes were characterized by elemental analysis, FT‐IR spectroscopy and single‐crystal X‐ray diffraction. Complexes 1 and 3 have the same one‐dimensional (1D) chain while 2 is a 6‐connected twofold interpenetrating three‐dimensional (3D) network with α ‐Po 4¹²·6³ topology based on the binuclear Cd^II subunits. Compound 4 features a puckered two‐dimensional (2D) (4,4) network, and the large voids of the packing 2D nets have accommodated the uncoordinated L guest molecules. An abundant of N–H···O, O–H···O and C–H···O hydrogen bonding interactions exist in complexes 1–4 , which contributes to stabilize the crystal structure and extend the low‐dimensional entities into high‐dimensional frameworks. Lastly, the photoluminiscent properties of compounds 2 were also investigated.     

An unusual two‐dimensional hydrogen‐bonding network in bis(2,9‐dimethyl‐1,10‐phenanthrolin‐1‐ium) peroxodisulfate dihydrate

The title compound, 2C₁₄H₁₃N₂⁺·S₂O₈²⁻·2H₂O, is a protonated amine salt which is formed from two rather uncommon ionic species, namely a peroxodisulfate (pds²⁻) anion, which lies across a crystallographic inversion centre, and a 2,9‐dimethyl‐1,10‐phenanthrolin‐1‐ium (Hdmph⁺) cation lying in a general position. Each pds²⁻ anion binds to two water molecules through strong water–peroxo O—H...O interactions, giving rise to an unprecedented planar network of hydrogen‐bonded macrocycles which run parallel to (100). The atoms of the large R₈⁸(30) rings are provided by four water molecules bridging in fully extended form (...H—O—H...) and four pds²⁻ anions alternately acting as long (...O—S—O—O—S—O...) and short (...O—S—O...) bridges. The Hdmph⁺ cations, in turn, bind to these units through hydrogen bonds involving their protonated N atoms. In addition, the crystal structure also contains π–π and aromatic–peroxo C—H...O interactions.     

A hydrogen‐bonded heterodimer of 1‐(4‐hexyloxyphenyl)pyridin‐4(1H)‐one with 4‐cyano­benzoic acid

The two components of the title heterodimer, C₁₇H₂₁NO₂·C₈H₅NO₂, are linked end‐to‐end via O—H⋯O(=C) and C—H⋯O(=C) hydrogen‐bond inter­actions. Additional lateral C—H⋯O inter­actions link the dimers in a side‐by‐side fashion to produce wide infinite mol­ecular ribbons. Adjacent ribbons are inter­connected viaπ–π stacking and C—H⋯π(arene) inter­actions. This structure represents the first evidence of robust hydrogen‐bond formation between the moieties of pyridin‐4(1H)‐one and benzoic acid.     

A triangular palladium(II) supramolecular coordination complex based on 1,4‐bis(1H‐imidazol‐1‐yl)benzene and (2,2′‐bipyridyl)palladium(II) nitrate: synthesis and crystal structure

The self‐assembly of ditopic bis(1H‐imidazol‐1‐yl)benzene ligands ( L ^H) and the complex (2,2′‐bipyridyl‐κ²N,N′)bis(nitrato‐κO)palladium(II) affords the supramolecular coordination complex tris[μ‐bis(1H‐imidazol‐1‐yl)benzene‐κ²N³:N^3′]‐triangulo‐tris[(2,2′‐bipyridyl‐κ²N,N′)palladium(II)] hexakis(hexafluoridophosphate) acetonitrile heptasolvate, [Pd₃(C₁₀H₈N₂)₃(C₁₂H₁₀N₄)₃](PF₆)₆·7CH₃CN, 2 . The structure of 2 was characterized in acetonitrile‐d₃ by ¹H/¹³C NMR spectroscopy and a DOSY experiment. The trimeric nature of supramolecular coordination complex 2 in solution was ascertained by cold spray ionization mass spectrometry (CSI–MS) and confirmed in the solid state by X‐ray structure analysis. The asymmetric unit of 2 comprises the trimetallic Pd complex, six PF₆^? counter‐ions and seven acetonitrile solvent molecules. Moreover, there is one cavity within the unit cell which could contain diethyl ether solvent molecules, as suggested by the crystallization process. The packing is stabilized by weak inter‐ and intramolecular C—H…N and C—H…F interactions. Interestingly, the crystal structure displays two distinct conformations for the L ^H ligand (i.e. syn and anti), with an all‐syn‐[Pd] coordination mode. This result is in contrast to the solution behaviour, where multiple structures with syn/anti‐ L ^H and syn/anti‐[Pd] are a priori possible and expected to be in rapid equilibrium.     

Tris(2,2′‐bipyridine)iron(II) bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide) dihydrate: chiral hydrogen‐bonded frameworks interpenetrate in three dimensions

In the title compound, [Fe(C₁₀H₈N₂)₃](C₉H₅N₄O)₂·2H₂O, the chiral cations lie across twofold rotation axes in the space group C2/c. The anions and the water molecules are linked by two independent O—H...N hydrogen bonds to form C₂²(8) chains, and these chains are linked by the cations via C—H...N and C—H...O hydrogen bonds to form two interpenetrating three‐dimensional frameworks, each of which contains only one enantiomeric form of the chiral cation.