A three‐dimensional homochiral metal–organic framework constructed from manganese(II) with S‐carboxymethyl‐N‐(p‐tosyl)‐l‐cysteine and 4,4′‐bipyridine

In the chiral polymeric title compound, poly[aqua(4,4′‐bipyridine)[μ₃‐S‐carboxylatomethyl‐N‐(p‐tosyl)‐l ‐cysteinato]manganese(II)], [Mn(C₁₂H₁₃NO₆S₂)(C₁₀H₈N₂)(H₂O)]_n, the Mn^II ion is coordinated in a distorted octahedral geometry by one water molecule, three carboxylate O atoms from three S‐carboxyatomethyl‐N‐(p‐tosyl)‐l ‐cysteinate (Ts‐cmc) ligands and two N atoms from two 4,4′‐bipyridine molecules. Each Ts‐cmc ligand behaves as a chiral μ₃‐linker connecting three Mn^II ions. The two‐dimensional frameworks thus formed are further connected by 4,4′‐bipyridine ligands into a three‐dimensional homochiral metal–organic framework. This is a rare case of a homochiral metal–organic framework with a flexible chiral ligand as linker, and this result demonstrates the important role of noncovalent interactions in stabilizing such assemblies.     

A threefold interpenetrated two‐dimensional zinc(II) supramolecular architecture based on 3‐nitrobenzoic acid and 4,4′‐bipyridine

With regard to crystal engineering, building block or modular assembly methodologies have shown great success in the design and construction of metal–organic coordination polymers. The critical factor for the construction of coordination polymers is the rational choice of the organic building blocks and the metal centre. The reaction of Zn(OAc)₂·2H₂O (OAc is acetate) with 3‐nitrobenzoic acid (HNBA) and 4,4′‐bipyridine (4,4′‐bipy) under hydrothermal conditions produced a two‐dimensional zinc(II) supramolecular architecture, catena‐poly[[bis(3‐nitrobenzoato‐κ²O,O′)zinc(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′], [Zn(C₇H₄NO₄)₂(C₁₀H₈N₂)]_n or [Zn(NBA)₂(4,4′‐bipy)]_n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray diffraction analysis. The Zn^II ions are connected by the 4,4′‐bipy ligands to form a one‐dimensional zigzag chain and the chains are decorated with anionic NBA ligands which interact further through aromatic π–π stacking interactions, expanding the structure into a threefold interpenetrated two‐dimensional supramolecular architecture. The solid‐state fluorescence analysis indicates a slight blue shift compared with pure 4,4′‐bipyridine and HNBA.     

A novel one‐dimensional zinc coordination polymer containing 4‐methylbenzoate and 4,4‐bipyridine

The title compound, catena‐poly[[tris(μ‐4‐methylbenzoato)‐κ²O:O;κ⁴O:O′‐(4‐methylbenzoato‐κ²O,O′)dizinc(II)]‐μ‐4,4′‐bipyridine‐κ²N:N′], [Zn₂(C₈H₇O₂)₄(C₁₀H₈N₂)]_n, is a novel coordination polymer. The asymmetric unit contains two unique Zn^II ions, four 4‐methylbenzoate ligands and one 4,4′‐bipyridine (4,4′‐bpy) ligand, all in general positions. The four 4‐methylbenzoate ligands link the two Zn^II centres to form a dinuclear unit, with a Zn...Zn separation of 3.188 (2) Å, which can be regarded as a supramolecular secondary building unit (SBU). These SBUs are further bridged by 4,4′‐bpy ligands, forming a novel one‐dimensional infinite chain. There are π–π stacking interactions between the benzene rings of the 4‐methylbenzoate ligands and the pyridyl rings of the 4,4′‐bpy ligands, leading to the formation of a corrugated layer. These layers are further assembled via C—H...O hydrogen bonds into a three‐dimensional supramolecular network structure. Coordination polymers such as the title compound are of interest for their potential applications as functional materials.     

μ‐4,4′‐Bipyridine‐κ2N:N′‐bis[triaqua(4,4′‐bipyridine‐κN)cadmium(II)] bis(3‐aminobenzoate) bis(perchlorate) dihydrate: a novel supramolecular system constructed by π–π and hydrogen‐bonding interactions

The title dicadmium compound, [Cd₂(C₁₀H₈N₂)₅(H₂O)₆](C₇H₆NO₂)₂(ClO₄)₂·2H₂O, is located around an inversion centre. Each Cd^II centre is coordinated by three N atoms from three different 4,4′‐bipyridine ligands and three O atoms from three coordinating water molecules in a distorted octahedral coordination environment. In the dicadmium cation unit, one 4,4′‐bipyridine (4,4′‐bipy) molecule acts as a bidentate bridging ligand between two Cd metal ions, while the other four 4,4′‐bipy molecules act only as monodentate terminal ligands, resulting in a rare `H‐type' [Cd₂(C₁₀H₈N₂)₅(H₂O)₆] host unit. These host units are connected to each other viaπ–π stacking interactions, giving rise to a three‐dimensional supramolecular grid network with large cavities. The 3‐aminobenzoate anions, perchlorate anions and water molecules are encapsulated in the cavities by numerous hydrogen‐bonding interactions. To the best of our knowledge, this is the first example of a coordination compound based on both 4,4′‐bipyridine ligands together with discrete 3‐aminobenzoate anions.     

A two‐dimensional copper(II) coordination polymer based on 2,4′‐oxybis(benzoate) and 4,4′‐bipyridine

The reaction of Cu(NO₃)₂·3H₂O with 2,4′‐oxybis(benzoic acid) and 4,4′‐bipyridine under hydrothermal conditions produced a new mixed‐ligand two‐dimensional copper(II) coordination polymer, namely poly[[(μ‐4,4′‐bipyridine‐κ²N ,N ′)[μ‐2,4′‐oxybis(benzoato)‐κ⁴O ²,O ^2′:O ⁴,O ^4′]copper(II)] monohydrate], {[Cu(C₁₄H₈O₅)(C₁₀H₈N₂)]·H₂O}_n , which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single‐crystal X‐ray diffraction. The X‐ray diffraction crystal structure analysis reveals that the Cu^II ions are connected to form a two‐dimensional wave‐like network through 4,4′‐bipyridine and 2,4′‐oxybis(benzoate) ligands. The two‐dimensional layers are expanded into a three‐dimensional supramolecular structure through intermolecular O—H…O and C—H…O hydrogen bonds. Furthermore, magnetic susceptibility measurements indicate that the complex shows weak antiferromagnetic interactions between adjacent Cu^II ions.     

catena‐Poly[[[cis‐aqua­bis(4‐carboxy­cyclo­hexane‐1‐carboxyl­ato‐κ2O,O′)cadmium(II)]‐μ‐4,4′‐bipyridine‐κ2N:N] monohydrate]

The title complex, {[Cd(C₈H₁₁O₄)₂(C₁₀H₈N₂)(H₂O)]·H₂O}_n, consists of linear chains formed through 4,4′‐bipyridine ligands linking seven‐coordinated Cd^II ions. Each Cd^II ion is in a distorted penta­gonal–bipyramidal environment, coordinated by one water ligand, two 4‐carboxy­cyclo­hexane‐1‐carboxyl­ate ligands and one bridging 4,4′‐bipyridine ligand to generate linear chains. The water mol­ecules and the Cd atom on one side, and the 4,4′‐bipyridine unit on the other, are bisected by two sets of twofold axes. The carboxylate group of the 4‐carboxy­cyclo­hexane‐1‐carboxyl ligand chelates a Cd^II ion, while the (protonated) carboxyl group forms hydrogen bonds with adjacent chains, resulting in a layered structure. This is the first reported occurrence of a dicarboxycyclo­hexane ligand exhibiting a non‐bridging coordination mode.     

The cocrystal of 3‐hydroxy‐2‐naphthoic acid and 4,4′‐bipyridine

4,4′‐Bipyridine cocrystallizes with 3‐hydroxy‐2‐naphthoic acid in a 1:2 ratio to give a centrosymmetric three‐component supra­molecular adduct, namely 3‐hydroxy‐2‐naphthoic acid–4,4′‐bipyridine (2/1), C₁₁H₈O₃·0.5C₁₀H₈N₂, in which 4,4′‐bipyridine is located on an inversion center. The pyridine–carboxylic acid heterosynthon generates an infinite one‐dimensional hydrogen‐bonded chain viaπ–π inter­actions between naphthyl and 4,4′‐bipyridine groups. The one‐dimensional chains are further assembled into a three‐dimensional network by weak C—H⋯π inter­actions between pyridyl and naphthyl rings, and C—H⋯O inter­actions between 3‐hydroxy‐2‐naphthoic acid mol­ecules.     

4,4′‐Methylenediphenol–4,4′‐bipyridine (2/3): decarboxylation of 5,5′‐methylenedisalicylic acid under hydrothermal conditions

Reaction of 5,5′‐methylenedisalicylic acid (5,5′‐H₄mdsa) with 4,4′‐bipyridine (4,4′‐bipy) and manganese(II) acetate under hydrothermal conditions led to the unexpected 2:3 binary cocrystal 4,4′‐methylenediphenol–4,4′‐bipyridine (2/3), C₁₃H₁₂O₂·1.5C₁₀H₈N₂ or (4,4′‐H₂dhdp)(4,4′‐bipy)_1.5, which is formed with a concomitant decarboxylation. The asymmetric unit contains one and a half 4,4′‐bipy molecules, one of which straddles a centre of inversion, and one 4,4′‐H₂dhdp molecule. O—H...N interactions between the hydroxy and pyridyl groups lead to a discrete ribbon motif with an unusual 2:3 stoichiometric ratio of strong hydrogen‐bonding donors and acceptors. One of the pyridyl N‐atom donors is not involved in hydrogen‐bond formation. Additional weak C—H...O interactions between 4,4′‐bipy and 4,4′‐H₂dhdp molecules complete a two‐dimensional bilayer supramolecular structure.     

Cocrystallization of adamantane‐1,3‐dicarboxylic acid and 4,4′‐bipyridine

The cocrystallization of adamantane‐1,3‐dicarboxylic acid (adc) and 4,4′‐bipyridine (4,4′‐bpy) yields a unique 1:1 cocrystal, C₁₂H₁₆O₄·C₁₀H₈N₂, in the C2/c space group, with half of each molecule in the asymmetric unit. The mid‐point of the central C—C bond of the 4,4′‐bpy molecule rests on a center of inversion, while the adc molecule straddles a twofold rotation axis that passes through two of the adamantyl C atoms. The constituents of this cocrystal are joined by hydrogen bonds, the stronger of which are O—H...N hydrogen bonds [O...N = 2.6801 (17) Å] and the weaker of which are C—H...O hydrogen bonds [C...O = 3.367 (2) Å]. Alternate adc and 4,4′‐bpy molecules engage in these hydrogen bonds to form zigzag chains. In turn, these chains are linked through π–π interactions along the c axis to generate two‐dimensional layers. These layers are neatly packed into a stable crystalline three‐dimensional form via weak C—H...O hydrogen bonds [C...O = 3.2744 (19) Å] and van der Waals attractions.     

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.     

catena‐Poly­[[bis­(hexa­fluoro­acetyl­acetonato‐κ2O,O′)­zinc(II)]‐μ‐4,4′‐bi­pyridine‐κ2N:N′]

The structure of the title compound, catena‐poly[[bis(1,1,1,5,5,5‐hexafluoropentane‐2,4‐dionato‐κ²O,O′)zinc(III)]‐μ‐4,4′‐bipyridine‐κ²N:N′], [Zn(C₅HF₆O₂)₂(C₁₀H₈N₂)]_n, con­sists of polymeric chains, running in two perpendicular directions, organized as planes normal to the tetragonal axis. The elemental unit of the chains is the zinc(II) coordination polyhedron bisected by a twofold symmetry axis, and thus only half of the unit is independent. The octahedral coordination geometry of the metal centre is composed of two oxy­gen‐chelating (symmetry‐related) hexa­fluoro­acetyl­acetonate groups and two translationally related 4,4′‐bi­pyridine groups, which act as connecting agents in the polymer structure. The stabilization of this architecture of chains and planes is associated with a number of weak C—H⋯O and C—H⋯F hydrogen bonds.     

A hydrostable and twofold interpenetrating three‐dimensional zinc–organic framework with rob topology based on 4,4′‐oxydibenzoate and 3,3′‐dimethyl‐4,4′‐bipyridine ligands

Metal–organic frameworks (MOFs) are a new class of porous materials that have received widespread attention due to their potential applications in gas storage and/or separation, catalysis, luminescence, and so on. The title compound, poly[[(μ₂‐3,3′‐dimethyl‐4,4′‐bipyridine‐κ²N:N′)bis(μ₄‐4,4′‐oxydibenzoato‐κ⁴O:O′:O′′:O′′′)dizinc] tetrahydrate], {[Zn₂(C₁₄H₈O₅)₂(C₁₂H₁₂N₂)]·4H₂O}_n, has been prepared by the solvothermal assembly of Zn(NO₃)₂·6H₂O, 4,4′‐oxydi(benzoic acid) and 3,3′‐dimethyl‐4,4′‐bipyridine. The two Zn^II atoms adopt the same five‐coordinated distorted square‐pyramidal geometry (i.e. ZnO₄N), bonding to four O atoms from four different 4,4′‐oxydibenzoate (oba) ligands and one N atom from a 3,3′‐dimethyl‐4,4′‐bipyridine (dmbpy) ligand. The supramolecular secondary building unit (SBU) is a paddle‐wheel [Zn₂(COO)₄] unit and these units are linked by oba ligands within the layer to form a two‐dimensional net parallel to the b axis, with the dmbpy ligands pointing alternately up and down, which is further extended by dmbpy ligands to form a three‐dimensional framework with rob topology. The single net leaves voids that are filled by mutual interpenetration of an independent equivalent framework in a twofold interpenetrating architecture. The title compound shows thermal stability up to 673 K and is stable in aqueous solutions in the pH range 5–9. Excitation and luminescence data observed at room temperature show that it emits a bright‐blue fluorescence.     

1,1′‐Diethyl‐4,4′‐bipyridine‐1,1′‐diium bis(1,1,3,3‐tetracyano‐2‐ethoxypropenide): multiple C—H...N hydrogen bonds form a complex sheet structure

In the title salt, C₁₄H₁₈N₂²⁺·2C₉H₅N₄O⁻, the 1,1′‐diethyl‐4,4′‐bipyridine‐1,1′‐diium dication lies across a centre of inversion in the space group P2₁/c. In the 1,1,3,3‐tetracyano‐2‐ethoxypropenide anion, the two independent –C(CN)₂ units are rotated, in conrotatory fashion, out of the plane of the central propenide unit, making dihedral angles with the central unit of 16.0 (2) and 23.0 (2)°. The ionic components are linked by C—H...N hydrogen bonds to form a complex sheet structure, within which each cation acts as a sixfold donor of hydrogen bonds and each anion acts as a threefold acceptor of hydrogen bonds.     

Two isomorphous transition metal complexes displaying a coordinated tetrathionate unit: bis(4,4′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)(tetrathionato‐κ2S,S′)cadmium(II) dimethylformamide disolvate and the zinc(II) analogue

The isomorphous title compounds, [Tr(S₄O₆)(C₁₂H₁₂N₂)₂]·2C₃H₇NO (Tr = Cd^II and Zn^II), consist of metal centres to which one tetrathionate and two 4,4′‐dimethyl‐2,2′‐bipyridine chelating ligands bind. The structures are completed by two symmetry‐related dimethylformamide solvent molecules. Each metal‐centred complex is bisected by a twofold axis running through the metal centre and halving the chelating tetrathionate dianion through the central S—S bond. The ancillary symmetry‐related 4,4′‐dimethyl‐2,2′‐bipyridine ligands act as chelates. This results in a distorted six‐coordinate geometry, with similar Tr—O/N distances but central angles differing substantially from 90 and 180°. Both ligands are basically featureless from a geometric point of view, with torsion angles in both coordinated tetrathionate groups suggesting a trend linking metal size (covalent radius) and ligand `openness'. Packing is directed by (C—H)_aromatic...O bridges and π–π offset stacked interactions defining chains along [001], further linked by weaker (C—H)_methyl...O bridges, some of them mediated by the dimethylformamide solvent molecules.     

Poly[diaqua(μ‐4,4′‐bipyridine‐κ2N:N′)bis(μ‐cyanido‐κ2C:N)bis(cyanido‐κC)nickel(II)copper(II)]: a metal–organic cyanide‐bridged framework

The structure of the title compound, [NiCu(CN)₄(C₁₀H₈N₂)(H₂O)₂]_n or [{Cu(H₂O)₂}(μ‐C₁₀H₈N₂)(μ‐CN)₂{Ni(CN)₂}]_n, was shown to be a metal–organic cyanide‐bridged framework, composed essentially of –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains (4,4′‐bpy is 4,4′‐bipyridine) linked by [Ni(CN)₄]²⁻ anions. Both metal atoms sit on special positions; the Cu^II atom occupies an inversion center, while the Ni^II atom of the cyanometallate sits on a twofold axis. The 4,4′‐bpy ligand is also situated about a center of symmetry, located at the center of the bridging C—C bond. The scientific impact of this structure lies in the unique manner in which the framework is built up. The arrangement of the –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains, which are mutually perpendicular and non‐intersecting, creates large channels running parallel to the c axis. Within these channels, the [Ni(CN)₄]²⁻ anions coordinate to successive Cu^II atoms, forming zigzag –Cu—N[triple‐bond]C—Ni—C[triple‐bond]N—Cu– chains. In this manner, a three‐dimensional framework structure is constructed. To the authors' knowledge, this arrangement has not been observed in any of the many copper(II)–4,4′‐bipyridine framework complexes synthesized to date. The coordination environment of the Cu^II atom is completed by two water molecules. The framework is further strengthened by O—H...N hydrogen bonds involving the water molecules and the symmetry‐equivalent nonbridging cyanide N atoms.     

The layered compound poly[μ2‐4,4′‐bipyridyl‐di‐μ2‐chlorido‐mercury(II)]

The title compound, [HgCl₂(C₁₀H₈N₂)]_n, features two‐dimensional [HgCl₂(4,4′‐bipy)]_n neutral networks (4,4′‐bipy is 4,4′‐bipyridine), based on an octahedral Hg atom coordinated by four μ₂‐Cl atoms and two μ₂‐4,4′‐bipy ligands in trans positions, yielding a HgCl₄N₂ octahedron. The structure has mmm symmetry about the Hg atoms, with most of the atoms on at least one mirror plane, but the unsubstituted C atoms of the 4,4′‐bipy rings are disordered across a mirror plane. Photoluminescent investigations reveal that the title compound displays a strong emission in the green region, which probably originates from a ligand‐to‐ligand charge‐transfer transition.     

Synthesis and photophysical properties of novel amphiphilic ruthenium (II) complexes containing 4,4′‐dialkylaminomethyl‐2,2′‐bipyridyl ligands

The synthesis of a number of new 2,2′‐bipyridine ligands functionalized with bulky amino side groups is reported. Three homoleptic polypyridyl ruthenium (II) complexes, [Ru(L)₃]²⁺ 2(PF₆^?), where L is 4,4′‐dioctylaminomethyl‐2,2′‐bipyridine (Ru4a), 4,4′‐didodecylaminomethyl‐2,2′‐bipyridine (Ru4b) and 4,4′‐dioctadodecylaminomethyl‐2,2′‐bipyridine (Ru4c), have been synthesized. These compounds were characterized and their photophysical properties examined. The electronic spectra of three complexes show pyridyl π → π* transitions in the UV region and metal‐to‐ligand charge transfer bands in the visible region. Copyright © 2005 John Wiley & Sons, Ltd.     

Bis(3‐amino­pyridine‐κN)(4,4′‐di­methyl‐2,2′‐bipyridine‐κ2N,N′)(per­chlorato‐κO)copper(II) per­chlorate

The title compound, [Cu(ClO₄)(C₅H₆N₂)₂(C₁₂H₁₂N₂)]ClO₄, was prepared by in situ partial ligand substitution between 3‐amino­pyridine and 4,4′‐dimethyl‐2,2′‐bipyridine at room temperature. The central copper(II) ion is five‐coordinated by one bidentate 4,4′‐dimethyl‐2,2′‐bipyridine mol­ecule, two monodentate pyridine‐coordinated 3‐amino­pyridine mol­ecules and one apical O atom from the perchlorate counter‐ion. Inter­molecular N—H⋯O and C—H⋯O hydrogen‐bonding inter­actions form a hydrogen‐bond‐sustained network.     

New enantiopure palladium(II) complexes from a stereodynamic 2,2′‐biphosphole ligand

Two enantiopure palladium(II) complexes, viz. [1,1′‐(butane‐1,3‐diyl)‐3,3′,4,4′‐tetramethyl‐5,5′‐diphenyl‐2,2′‐biphosphole]dichloridopalladium(II) dichloromethane solvate [systematic name: dichlorido(1,2,5,10,11‐pentamethyl‐3,9‐diphenylperhydrodicyclopenta[a,c][1,4]diphosphepine‐κ²P,P′)palladium(II) dichloromethane solvate], [PdCl₂(C₂₈H₃₀P₂)]·CH₂Cl₂, have been synthesized from stereodynamic diphosphines derived from 2,2′‐biphosphole through a metal kinetic dynamic resolution. In both structures, the coordination around the metal atom is square planar, with a cis arrangement of the ligands that drastically reduces the dihedral angle between the two phosphole rings compared with the free ligand. The structural determination of both enantiomers unambiguously establishes the absolute configuration of both central and axial elements of chirality of the 2,2′‐biphosphole framework and indicates that the original carbon chirality of the backbone controls the chiralities of the 2,2′‐biphosphole framework.     

A new one‐dimensional nickel metal–organic framework: catena‐poly[[[diaquabis(4‐{[(1‐phenyl‐1H‐tetrazol‐5‐yl)sulfanyl]methyl}benzoato‐κO)nickel(II)]‐μ‐4,4′‐bipyridine‐κ2N:N′] monohydrate]

The title complex, {[Ni(C₁₅H₁₁N₄O₂S)₂(C₁₀H₈N₂)(H₂O)₂]·H₂O}_n, was synthesized by the reaction of nickel chloride, 4‐{[(1‐phenyl‐1H‐tetrazol‐5‐yl)sulfanyl]methyl}benzoic acid (HL) and 4,4′‐bipyridine (bpy) under hydrothermal conditions. The asymmetric unit contains two half Ni^II ions, each located on an inversion centre, two L⁻ ligands, one bpy ligand, two coordinated water molecules and one unligated water molecule. Each Ni^II centre is six‐coordinated by two monodentate carboxylate O atoms from two different L⁻ ligands, two pyridine N atoms from two different bpy ligands and two terminal water molecules, displaying a nearly ideal octahedral geometry. The Ni^II ions are bridged by 4,4′‐bipyridine ligands to afford a linear array, with an Ni...Ni separation of 11.361 (1) Å, which is further decorated by two monodentate L⁻ ligands trans to each other, resulting in a one‐dimensional fishbone‐like chain structure. These one‐dimensional fishbone‐like chains are further linked by O—H...O, O—H...N and C—H...O hydrogen bonds and π–π stacking interactions to form a three‐dimensional supramolecular architecture. The thermal stability of the title complex was investigated via thermogravimetric analysis.