A Novel Coordination Polymer, [Ag4^1 （bpdc）（H2bpdc）（Hbpdc）2]n （bpdc = 2,2＇-bipyridyl-3,3＇-dicarboxylate）： Coordination Models of bpdc Ligands

A novel coordination polymer, [Ag₄ppdc)(H₂bpdc)(Hbpdc)₂] (bpdc = 2,2′‐bipyridyl‐3,3′‐dicarboxylate), was hydrothermally synthesized at 403 K and structurally characterized by single crystal X‐ray diffraction analysis. The compound crystalizes in the monoclinic space group C2/c with a=1.9516(4) nm, b=1.9503(4) nm. c=1.2566(3) nm, and β=112.48(3)°. In the two‐dimensional crystal structure, Ag^I center is coordinated, in a scarce coordination environment, double‐capped tetrahedron, by one bpdc ligand to form N‐Ag‐N chelate bond via two pyridyl N atoms, and other two bpdc ligands to form two O‐Ag‐O chelate bonds, respectively, via two carboxyl O atoms. The bpdc ligands are present in one non‐protonated form, bpdc, and two protonated forms, Hbpdc and H2bpdc, which all act as μ3‐ligand in a hexadentate fashion (N, N′; O, O′; O, O′) to coordinate with three Ag centers, respectively, through the three chelate bonds. This coordinated fashion of bpdc ligand is first found in the title compound. W‐Us‐NIR reflectance spectroscopy study revealed insulator nature for the crystal with an optical energy gap of 3.1 eV.     

Two new soluble iron–oxo complexes: [Fe2(μ‐O)(μ‐O2CCF3)2(O2CCF3)2(C10H8N2)2] and [Fe4(μ3‐O)2(μ‐O2CCF3)6(O2CCF3)2(C10H8N2)2]·CF3CO2H

Two new iron–oxo clusters, viz. di‐μ‐tri­fluoro­acetato‐μ‐oxo‐bis­[(2,2′‐bi­pyridine‐κ²N,N′)(tri­fluoro­acetato‐κO)­iron(III)], [Fe₂O(CF₃CO₂)₄(C₁₀H₈N₂)₂], and bis(2,2′‐bi­pyridine)­di‐μ₃‐oxo‐hexa‐μ‐tri­fluoro­acetato‐bis­(tri­fluoro­acetato)­tetrairon(III) tri­fluoro­acetic acid solvate, [Fe₄O₂(CF₃CO₂)₈(C₁₀H₈N₂)₂]·CF₃CO₂H, contain dinuclear and tetranuclear Fe^III cores, respectively. The Fe^III atoms are in distorted octahedral environments in both compounds and are linked by oxide and tri­fluoro­acetate ions. The tri­fluoro­acetate ions are either bridging (bidentate) or coordinated to the Fe^III atoms via one O atom only. The fluorinated peripheries enhance the solubility of these compounds. Formal charges for all the Fe centers were assigned by summing valences of the chemical bonds to the Fe^III atom.     

Bis[diaquabis(2,2‐bipyridine N,N′‐dioxide‐κ2O,O′)cobalt(II)] ξ‐octamolybdate dihydrate

The title organic–inorganic hybrid compound, [Co(C₁₀H₈N₂O₂)₂(H₂O)₂]₂[Mo₈O₂₆]·2H₂O, consists of [Co(bpdo)₂(H₂O)₂]²⁺ (bpdo is 2,2‐bipyridine N,N′‐dioxide) and ξ‐[Mo₈O₂₆]⁴⁻ groups in a 2:1 ratio, plus two water solvent molecules. The independent Co atom in the cation is coordinated by four O atoms from two bpdo ligands and two water molecules, in a distorted octahedral geometry. The counter‐anions, built up around a symmetry center, are linked by solvent water molecules through O—H...O hydrogen bonds to generate two‐dimensional layers, which are in turn linked by coordinated water molecules from the cationic units through further O—H...O hydrogen bonds, forming a three‐dimensional supramolecular structure.     

Bis[μ3‐cis‐N‐(2‐aminopropyl)‐N′‐(2‐carboxylatophenyl)oxamidato(3–)]bis(2,2′‐bipyridine)dichloridotetracopper(II) dihydrate

The title complex, bis[μ₃‐cis‐N‐(2‐aminopropyl)‐N′‐(2‐carboxylatophenyl)oxamidato(3−)]‐1:2:4κ⁷N,N′,N′′,O:O′,O′′:O′′′;2:3:4κ⁷O′′′:N,N′,N′′,O:O′,O′′‐bis(2,2′‐bipyridine)‐2κ²N,N′;4κ²N,N′‐dichlorido‐1κCl,3κCl‐tetracopper(II) dihydrate, [Cu₄(C₁₂H₁₂N₃O₄)₂Cl₂(C₁₀H₈N₂)₂]·2H₂O, consists of a neutral cyclic tetracopper(II) system having an embedded centre of inversion and two solvent water molecules. The coordination of each Cu^II atom is square‐pyramidal. The separations of Cu^II atoms bridged by cis‐N‐(2‐aminopropyl)‐N′‐(2‐carboxylatophenyl)oxamidate(3−) and carboxyl groups are 5.2096 (4) and 5.1961 (5) Å, respectively. A three‐dimensional supramolecular structure involving hydrogen bonding and aromatic stacking is observed.     

4,4′‐Bis(2,2,2‐trifluoroethoxymethyl)‐2,2′‐bipyridine

As part of a homologous series of novel polyfluorinated bipyridyl (bpy) ligands, the title compound, C₁₆H₁₄F₆N₂O₂, contains the smallest fluorinated group, viz. CF₃. The molecule resides on a crystallographic inversion centre at the mid‐point of the pyridine C_ipso—C_ipso bond. Therefore, the bpy skeleton lies in an anti conformation to avoid repulsion between the two pyridyl N atoms. Weak intramolecular C—H...N and C—H...O interactions are observed, similar to those in related polyfluorinated bpy–metal complexes. A π–π interaction is observed between the bpy rings of adjacent molecules and this is probably a primary driving force in crystallization. Weak intermolecular C—H...N hydrogen bonding is present between one of the CF₃CH₂– methylene H atoms and a pyridyl N atom related by translation along the [010] direction, in addition to weak benzyl‐type C—H...F interactions to atoms of the terminal CF₃ group. It is of note that the O—CH₂CF₃ bond is almost perpendicular to the bpy plane.     

{Na2[Nd4(OX)(BDC)6(H2O)6]} n : A 3-D coordination polymer with hybrid dicarboxylates

The hydrothermal reactions of lanthanide ions, oxalates and benzenedicarboxylate with ratio of 4 : 1 : 8 at 190°C afford the three-dimensional coordination polymer Na₂[Nd₄(OX)(BDC)₆(H₂O)₆] (OX = oxalate and BDC = 1,3-benzenedicarboxylate dianion). Crystal data: C₂₅H₁₈NaNd₂O₁₇ M = 901.86, Triclinic, P 1, a = 10.335(6), b = 11.497(6), c = 12.238(7) Å, α = 93.015(9), β =114.892(8)°, γ = 95.970(10)°, V = 1304.3(12) ų, Z = 2, F(000) = 870, R ₁ = 0.0322, wR ₂ = 0.0683. The central oxalate of the unit cell coordinates with four lanthanides to form a four metal cluster [Ln₄(OX)]. The luminescence spectrum shows weak photoluminescence in infrared and near-infrared.     

Crystallographic report: A three‐dimensional coordination polymer: [Zn6(btc)4(4,4′‐bipy)5]n (btc = 1,2,4‐benzenetricarboxylate; 4,4′‐bipy = 4,4′‐bipyridine)

The three‐dimensional (3D) coordination polymer [Zn₆(btc)₄(4,4′‐bipy)₅]_n ( 1 ) (btc = 1,2,4‐benzenetricarboxylate; 4,4′‐bipy = 4,4′‐bipyridine) has been prepared hydrothermally. The zinc(II) centers in 1 are bridged by btc ligands to form a trinuclear subunit, which is further linked by 4,4′‐bipy and btc ligands to construct the 3D coordination architecture. Copyright © 2003 John Wiley & Sons, Ltd.     

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.     

The coordination polymer poly[bis[μ2‐2‐(2,2′‐bi‐1H‐imidazol‐1‐yl)acetato]cadmium]

The title compound, [Cd(C₈H₇N₄O₂)₂]_n, crystallizes in the centrosymmetric triclinic space group P with an asymmetric unit consisting of a bivalent Cd^II atom and two 2‐(2,2′‐bi‐1H‐imidazol‐1‐yl)acetate (BDAC⁻) anions. Two inversion‐related BDAC⁻ ligands are oppositely arranged and bind two Cd^II ions to form a [Cd₂(BDAC)₂] rhomboid subunit which is bridged by another BDAC⁻ ligand to form an infinite ladder along the a direction containing parallelogram grids. The three‐dimensional supramolecular architecture is formed by hydrogen bonds and C—H...π and π–π interactions.     

The 3D Supramolecular Compound {[Cu2(L‐val)2(4,4′‐bipy)(H2O)2](NO3)2}n (L‐val = L‐valine anion, 4,4′‐bipy = 4,4′‐bipyridine)

{[Cu₂(L‐val)₂(4,4′‐bipy)(H₂O)₂](NO₃)₂}_n was synthesized and its crystal structure was determined by X‐ray diffraction. In the presence of 4,4′‐bipyridine, deprotoned L‐valine chelates Cu^II ions into coordination layers which were linked into a framework by hydrogen‐bonded chains resulting from nitrate anions and water molecules.     

Poly[[trans‐diaquabis(μ2‐biphenyl‐2,2′‐dicarboxylato)bis(μ2‐4,4′‐bipyridine)dicobalt(II)] biphenyl‐2,2′‐dicarboxylic acid disolvate]

In the title compound, {[Co₂(C₁₄H₈O₄)₂(C₁₀H₈N₂)₂(H₂O)₂]·2C₁₄H₁₀O₄}_n, each Co^II ion is six‐coordinate in a slightly distorted octahedral geometry. Both Co^II ions are located on twofold axes. One is surrounded by two O atoms from two biphenyl‐2,2′‐dicarboxylate (dpa) dianions, two N atoms from two 4,4′‐bipyridine (bpy) ligands and two water molecules, while the second is surrounded by four O atoms from two dpa dianions and two N atoms from two bpy ligands. The coordinated dpa dianion functions as a κ³‐bridge between the two Co^II ions. One carboxylate group of a dpa dianion bridges two adjacent Co^II ions, and one O atom of the other carboxylate group also chelates to a Co^II ion. The Co^II ions are bridged by dpa dianions and bpy ligands to form a chiral sheet. There are several strong intermolecular hydrogen bonds between the H₂dpa solvent molecule and the chiral sheet, which result in a sandwich structure.     

The coordination polymer poly[(μ3‐3‐aminocarbonylpyrazine‐2‐carboxylato‐κ3N1:O2:O2′)silver(I)]

The title compound, [Ag(C₆H₄N₃O₃)]_n or [Ag(pyzca)]_n (where pyzca is 3‐aminocarbonylpyrazine‐2‐carboxylate), (I), was obtained by silver‐catalysed partial hydrolysis of pyrazine‐2,3‐dicarbonitrile in aqueous solution. The compound has a distorted trigonal–planar coordination geometry around the Ag^I ion, with each ligand bridging three Ag^I ions to form a one‐dimensional strand of molecules parallel to the b axis. An extensive hydrogen‐bond pattern connects these strands to form a three‐dimensional network of mog topology.     

(2,2′‐Biquinoline‐κ2N,N′)bis(nitrato‐κ2O,O′)copper(II)

In the title monomer, [Cu(NO₃)₂(C₁₈H₁₂N₂)], the six‐coordinated Cu^II atom lies on a twofold axis which bisects one of the ligands (a chelating biquinoline) and duplicates the remaining ligand, a chelating nitrate. The latter binds in a very asymmetric way, consistent with a Jahn–Teller distortion in the coordination polyhedron which, due to the triple chelation, is extremely distorted and difficult to describe in terms of any regular model.     

A novel cadmium(II) coordination polymer with biphenyl‐3,3′,4,4′‐tetra­carboxylic acid and 4,4′‐bipyridine

A novel cadmium(II) coordination polymer, poly[[[bis­(4,4′‐bipyridine)cadmium(II)]‐μ₃‐4,4′‐dicarboxy­biphenyl‐3,3′‐di­carboxyl­ato] 0.35‐hydrate], {[Cd(C₁₆H₈O₈)(C₁₀H₈N₂)₂]·0.35H₂O}_n, was obtained by reaction of Cd(CH₃COO)₂·3H₂O, 4,4′‐bipyridine (4,4′‐bpy) and biphenyl‐3,3′,4,4′‐tetra­car­boxylic acid (H₄L) under hydro­thermal conditions. Each Cd^II atom lies at the centre of a distorted octa­hedron, coordinated by four O atoms from three H₂L²⁻ ligands and N atoms from two monodentate 4,4′‐bpy ligands. Each H₂L²⁻ ligand coordinates to three Cd^II atoms through two carboxyl­ate groups, one acting as a bridging bidentate ligand and the other in a chelating bidentate fashion. Two Cd atoms, two H₂L²⁻ anions and four 4,4′‐bpy ligands form a ring dimer node, which links into an extended broad zonal one‐dimensional chain along the c axis.     

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.     

Bis(2,2′‐bipyridine)(dicyanamido)­copper(II) tetrafluoroborate

In the title compound, [Cu(C₂N₃)(C₁₀H₈N₂)₂]BF₄, the Cu^II atom shows distorted trigonal‐bipyramidal geometry, with the dicyan­amido ligand in the equatorial plane. The two out‐of‐plane Cu—N bond lengths to bi­pyridine are 2.006 (3) and 1.998 (3) Å, whereas the in‐plane Cu—N distances are 2.142 (3) and 2.043 (3) Å to the bi­pyridine, and 2.015 (3) Å to the dicyan­amide.     

Allosteric Binding of Capsaicin by a Bis(β‐cyclodextrin)‐2,2′‐bipyridine Receptor

A new β‐cyclodextrin‐based receptor that showed allosteric binding behavior towards capsaicin in aqueous solution was prepared. By NMR titration and nonlinear regression, we obtained binding constants, which increased more than fivefold when an effector (Zn²⁺) was bound to a central 2,2′‐bipyridine that acts as the allosteric center.     

一个新颖的由Zn配合物修饰的Keggin型钴钨酸盐：[Zn(2,2’-bipy)3]3{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2 }.H2O

通过水热合成技术,一个新颖的基于Zn配合物修饰的Keggin型钴钨酸的有机-无机杂化化合物：[Zn(2,2’-bipy)3]3{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2 }.H2O已经被合成,化合物通过红外光谱、热重分析和单晶X-射线衍射进行了表征。单晶X-射线衍射的结果显示标题化合物是由一个单支撑的{[Zn(2,2’-bipy)2(H2O)]2 [HCoW12O40] 2}6-多阴离子,三个[Zn(2,2’-bipy)3]2+阳离子和一个水分子构成。有趣的是[Zn(1)(2,2’-bipy)3]2+阳离子通过氢键连接在一起形成螺旋链。另外标题化合物在空气中是稳定的,并且在室温下显示了强的荧光。     

[Cu(C8H16N4O2)0.5{N(CN)2}]n,a novel ladder‐like coordination polymer

A new polymeric copper complex, viz.catena‐poly[[[μ‐N,N′‐bis(3‐amino­propyl)oxa­mid­ato‐κ⁶N,N′,O:N′′,N′′′,O′]­dicopper(II)]‐di‐μ‐dicyan­amido‐1:1′κ²N¹:N⁵;2:2′κ²N¹:N⁵], [Cu₂(C₈H₁₆N₄O₂)(C₂N₃)₂]_n or [Cu(oxpn)_0.5{N(CN)₂}]_n [where H₂oxpn is N,N′‐bis(3‐amino­propyl)­ox­amide], has been ­synthesized by the reaction of Cu(oxpn), [Cu(ClO₄)₂]·6H₂O and NaN₃. In the crystal structure, the Cu atom is five‐coordinate and has a square‐pyrimidal (SP) configuration. In the polymer, dicyan­amide (dca⁻) groups link Cu^II cations in a μ‐1,5‐bridging mode, generating novel ladders in which each step is composed of dimeric [Cu₂(oxpn)]²⁺ cations. Abundant hydrogen bonds connect the polymer ladders into a two‐dimensional network structure.     

A novel three‐dimensional heterometallic coordination polymer: poly[[hexaaquabis[μ3‐3,5‐dicarboxylatopyrazolato‐κ5O3,N2:N1,O5:O5′](μ2‐oxalato‐κ4O1,O2:O1′,O2′)copper(II)dierbium(III)] trihydrate]

The title novel heterometallic 3d–4f coordination polymer, {[CuEr₂(C₅HN₂O₄)₂(C₂O₄)(H₂O)₆]·3H₂O}_n, has a three‐dimensional metal–organic framework composed of two types of metal atoms (one Cu^II and two Er^III) and two types of bridging anionic ligands [3,5‐dicarboxylatopyrazolate(3−) (ptc³⁻) and oxalate]. The Cu^II atom is four‐coordinated in a square geometry. The Er^III atoms are both eight‐coordinated, but the geometries at the two atoms appear different, viz. triangular dodecahedral and bicapped trigonal prismatic. One of the oxalate anions is located on a twofold axis and the other lies about an inversion centre. Both oxalate anions act as bis‐bidentate ligands bridging the latter type of Er atoms in parallel zigzag chains. The pdc³⁻ anions act as quinquedentate ligands not only chelating the Cu^II and the triangular dodecahedral Er^III centres in a bis‐bidentate bridging mode, but also connecting to Er^III centres of both types in a monodentate bridging mode. Thus, a three‐dimensional metal–organic framework is generated, and hydrogen bonds link the metal–organic framework with the uncoordinated water molecules. This study describes the first example of a three‐dimensional 3d–4f coordination polymer based on pyrazole‐3,5‐dicarboxylate and oxalate, and therefore demonstrates further the usefulness of pyrazoledicarboxylate as a versatile multidentate ligand for constructing heterometallic 3d–4f coordination polymers with interesting architectures.