Synthesis,characterization and magnetic properties of coordination polymers of manganese with 1,1′-biphenyl-2,2′-dicarboxylic acid ligands

Three new coordination polymers have been synthesized from 1,1′-biphenyl-2,2′-dicarboxylic acid (2,2-dpa), nitrogen-containing coligands and Mn salts under hydrothermal conditions. The X-ray crystal structures of all three complexes are presented. With the change of nitrogen-containing ligand, the structural features of the complexes also change. The complex prepared without a nitrogen coligand exhibits a one-dimensional covalent chain-like structure, composed of the rare pentanuclear Mn building unit. The complex with 4,4′-bipyridine as a secondary ligand shows a two-dimensional layer structure. With the chelating ligand 1,10-phenanthroline, a discrete molecular complex is synthesized. The magnetic properties of the complex with 4,4′-bipyridine in the temperature range 1.99–300 K are reported.     

Two transition metal coordination polymers constructed from 3-aminobenzoate and 4,4′-bipyridine

Two new transition metal coordination polymers, [Zn(abz)(bipy)](ClO₄) (1) and [Mn(bipy)₅(H₂O)₆](ClO₄)_2?·?2(abz)?·?2(H₂O) (2) (bipy?=?4,4′-bipyridine, abz?=?3-aminobenzoate), were prepared and characterized by elemental analysis, FTIR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is a 2-D-layered network with a (4,4) net built up by bipy and 3-aminobenzoate ligands connecting two zinc nodes. Complex 2 is a 3-D supramolecular grid network constructed from close stacking bipy ligands of H-type cation units with large cavities hosting 3-aminobenzoate, perchlorate ions, and water. Solid state photoluminescence for 1 was also investigated.     

Synthesis,spectroscopic, and structural characterization of two malate zinc coordination polymers with imidazole or 2,2′-bipyridine

Zinc(II) coordination polymers, [Zn(Hmal)(im)(H₂O)] _n · 2nH₂O (1) and [Zn(Hmal)(bpy)] _n · 3nH₂O (2) (H₃mal = malic acid, im = imidazole, bpy = 2,2′-bipyridine), were synthesized from aqueous solution and characterized by elemental analyses, infrared and fluorescence spectra, thermogravimetric analyses, and single-crystal X-ray structural analyses. In 1, zinc is coordinated by imidazole, water, and tridentate malate in octahedral geometry. The β-carboxy group of malate further bridges with the other zinc forming 1-D polymeric chains. A pair of 1-D chains self-assemble to generate a double chain by strong hydrogen bonds between imidazole and malate. Furthermore, neighboring pairs of double chains are extended to form the final 3-D framework through intermolecular hydrogen bonds. In 2, the malates link Zn in a bidentate–monodentate fashion to form spiral-shaped chains that extend into a 3-D supramolecular structure by π–π stacking interactions and intermolecular hydrogen bonds. Complex 1 exhibits strong fluorescence at room temperature.     

Synthesis,structure, and characterization of a silver(I) coordination polymer with μ6-bridging 2,2′-bipyridyl-3,3′-dicarboxylate

A silver(I) coordination polymer, [Ag₂(bpdc)] _n (1) (H₂bpdc = 2,2′-bipyridyl-3,3′-dicarboxylic acid), has been synthesized and characterized. Compound 1 exhibits a 2-D network containing 1-D channels. Each (bpdc)^2? is an octadentate μ₆-1igand coordinating with six Ag(I)'s in 1. This coordination of (bpdc)^2? ligand is first observed here. Neighboring networks are arranged in a [ABAB···] pattern to form 3-D supramolecular architecture by π···π stacking. Compound 1 shows intense photoluminescence at room temperature.     

Synthesis,characterization, and interaction with DNA of Cu(II) and Zn(II) complexes with 2,2′-bipyridyl-6,6′-dicarboxylic acid

Two transition metal complexes, [Cu₂(bpdc)₂H₂O]·2H₂O (1) and Zn(bpdc)(H₂O)₂ (2) (H₂bpdc?=?2,2′-bipyridine-6,6′-dicarboxylic acid), were synthesized and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is dinuclear with two five-coordinate cupric ions and 2 is mononuclear with one six-coordinate zinc. Interactions of 1 and 2 with DNA have been investigated using UV–Vis absorption spectra. The cleavage reaction on DNA has been monitored by agarose gel electrophoresis.     

Synthesis and characterization of two novel organic–inorganic hybrid solids from Keggin ions and metal coordination complexes

Two new hybrid compounds, [Co(4,4′-bpy)₂(H₂O)₄][(4,4′-bpyH₂]₂[CoW₁₂O₄₀]·8H₂O (1) and [Fe(2,2′-bpy)₃]₃[H₂W₁₂O₄₀]·6H₂O (2), (4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine) have been hydrothermally synthesized. These solids were characterized by elemental analysis, thermogravimetric analysis, UV–Vis spectroscopy and X-ray diffraction. The hydrogen-bonding interactions in 1 lead to the formation of a three dimensional network consisting of [CoW₁₂O₄₀]⁶⁻ anionic clusters, [Co(4,4′-bpy)₂(H₂O)₄]²⁺ cations and lattice water molecules, while the discrete Keggin ion [H₂W₁₂O₄₀]⁶⁻ in compound 2 is surrounded by 14 [Fe(2,2′-bpy)₃]²⁺ complexes through CH?O interactions (2.24–2.56 Å).     

Synthesis,crystal structures and photoluminescence of three new Mn(II) coordination polymers assembled from 2,4′-diphenic acid

Three new metal coordination polymers, [Mn(Hdpa)₂(4,4′-bipy)₂] _n (1), [Mn(dpa)(1,10-phen)(H₂O)] _n (2), and [Mn(dpa)(2,2′-bipy)] _n (3) (H₂dpa = 2,4′-biphenyl-dicarboxylic acid, 4,4′-bipy = 4,4′-bipyridine, 1,10-phen = 1,10-phenanthroline, and 2,2′-bipy = 2,2′-bipyridine), have been synthesized and characterized by elemental analysis, IR, and X-ray diffraction. Single-crystal X-ray analyses reveal that 2,4′-diphenic acid is a bridging ligand, exhibiting three coordination modes to link metal ions: μ ₁-η ¹: η ¹/μ ₀-η ⁰: η ⁰; μ ₂-η ²: η ⁰/μ ₁-η ¹: η ⁰; and μ ₂-η ¹: η ¹/μ ₂-η ¹: η ¹. Intermolecular hydrogen bonds in 1 lead to a zigzag chain. In 2, the 2-D supramolecular arrays extended along b-axis through π–π interactions between 1,10-phen. The dinuclear paddle-wheel second building units (SBUs) constructed by four dpa^2? ligands in 3 are linked by dpa^2? into double-strand chains. The fluorescence of H₂dpa and 1–3 are also determined.     

Mononuclear manganese and tetranuclear copper compounds and their supramolecular networks constructed from hexafluoroglutaric acid and 2,2′-bipyridine

Mn(2,2′-bpy)₂(HFGA) (1) and [Cu₄(μ₃-OH)₂(μ₂-OH)₂(H₂O)₂(2,2′-bpy)₄]?·?2HFGA?·?4H₂O (2) (H₂HFGA?=?hexafluoroglutaric acid and 2,2′-bpy?=?2,2′-bipyridine) have been synthesized and characterized by X-ray structural analyses. 1 is a monomer with six-coordinate Mn²⁺ from two oxygens of HFGA and four nitrogens of two 2,2′-bpy. Complex 2 is tetranuclear with four Cu²⁺ ions bridged by triple-bridging μ₃-OH and double-bridging μ₂-OH. There are two crystallographically independent Cu²⁺ ions in different five-coordinate environments. Cu1 is coordinated by 2,2′-bpy and three OH ligands. Cu2 is coordinated by 2,2′-bpy, two μ₃-OH ligands, and one water molecule. The mononuclear and tetranuclear molecules as building blocks are connected to construct different 3-D supramolecular architectures via noncovalent interactions. Particularly, the lone pair (lp)–π (F···π) interaction in 1 is observed. A hybrid water-anionic tape by linkage of {[(H₂O)₄(HFGA)]₂ ^4?} _n fragments consisting of water dimers and HFGA anions in 2 is observed.     

Two 2-D lanthanide coordination polymers constructed from hydroquinone-O,O′-diacetic acid

Two new coordination polymers, {Ln₂(hqda)₃(H₂O)₄·6H₂O}_n (H₂hqda = hydroquinone-O,O′-diacetic acid, Ln = Dy, 1; Ho, 2), were prepared and characterized by elemental analysis, IR spectroscopy, TG-DTA, fluorescence spectroscopy, and single-crystal X-ray diffraction. The two complexes are isomorphous with similar crystal structures. In 1 and 2, each Ln(III) ion is nine coordinate with seven oxygen atoms from hqda ligands and two oxygen atoms from water molecules. Two adjacent Ln(III) ions are bridged by–COO^? groups from hqda ligands in bidentate-bridging and chelating-bridging modes. These building blocks cross link through ^–OOCCH₂OC₆H₄OCH₂COO^? spacers to form a 2–D network structure. The adjacent 2-D layers are further interlinked by hydrogen bonds to form a 3-D supermolecular structure.     

Hydrothermal synthesis and characterization of a zigzag neodymium-2,2′-bipyridine-3,3′-dicarboxylate-isonicotinate coordination polymer

A new neodymium(III) coordination polymer, {[Nd(bpdc)(iso)(H₂O)₂] ? (H₂O)_2.25} _n (1), was synthesized by treating neodymium oxide with 2,2′-bipyridine-3,3′-dicarboxylic acid (H₂bpdc), and isonicotinic acid (Hiso) under hydrothermal conditions. Single-crystal X-ray diffraction shows that 1 is a 1-D zigzag chain and extends to 2-D network structure through π–π interactions and hydrogen bonds. Thermogravimetric analysis of 1 displays a considerable thermal stability. The variable-temperature magnetic susceptibility of 1 was measured.     

Synthesis, structural features and biological activities of three asymmetric pyridazine–triazole coordination polymers

The complexes [CuL₂Cl₂]_n (1), [CoL₂Cl₂(H₂O)₂]·L (2) and [MnL₂Cl₂(H₂O)₂]·L (3) (L = 3-chloro-6-(1H-1,2,4-triazol-1-yl) pyridazine) were synthesized and characterized by physicochemical and spectroscopic methods. X-ray crystallographic analysis reveals that the Cu(II) center of complex 1 is located in a slightly distorted tetragonal pyramidal environment and bridged by chlorine atoms to generate infinite 1D chains, which are further connected into 2D supramolecular structures by C–H…Cl hydrogen bonds. The Co(II) and Mn(II) atoms in complexes 2 and 3 both have a distorted octahedral coordination sphere, and the crystal lattices include hydrogen bonds and π–π stacking interactions to yield 3D supramolecular frameworks. The antioxidant activities (influence on O₂ ^?? and ^?OH) and antibacterial activities of the ligand L and its three complexes were also investigated.     

Synthesis,characterization and magnetic properties of supramolecular metal–organic complexes constructed from flexible–rigid mixed ligands

Two new supramolecular metal–organic complexes have been synthesized under hydrothermal conditions. Complex 1 exhibits a three-dimensional supramolecular network, constructed from [Co₂(H₃BPTC)₂(phen)₂] (H₄BPTC = 3,3′4,4′-benzophenone tetracarboxylate acid, phen = 1,10-phenanthroline) discrete units. Complex 2 similarly exhibits discrete [Cu₂(DPA)₂(bipy)₂(H₂O)₂] (DPA = 1,1′-biphenyl-2,2′-dicarboxylate acid, bipy = 2,2′-bipyridine) units, which are linked to form a three-dimensional supramolecular network through π–π interactions. It is interesting that during the synthesis of complex 1, the H₄BPTC ligands undergo partial decomposition to give 1,2,4-benzenetricarboxylate (H₃BTC) ligands, which react with Co to form [Co₃(BTC)₂]_n (3). Complex 3 shows a three-dimensional covalent network. The magnetic properties of complexes 1 and 2 have been studied.     

Monomeric and polymeric structures derived from 3,3′,4,4′-biphenyltetracarboxylic acid, phenanthroline and metal ions

Under similar hydrothermal synthetic conditions, the reactions of Fe(NO₃)₃/FeCl₂, CuCl₂, NiCl₂, and CdCl₂ with phenanthroline (phen) and 3,3′,4,4′-biphenyltetracarboxylic acid (H₄BPTC) afforded complexes [Fe(phen)₃](H₃BPTC)₂ (1), [Cu(phen)(BPTC)_0.5 · H₂O] · H₂O (2), [Ni₃(phen)₃(BPTC)_1.5(H₂O)₅] · 4H₂O (3) and [Cd(phen)(BPTC)_0.5] · H₂O (4). The short Fe–N distance in the monomeric Fe(phen)₃(H₃ BPTC)₂ (1) shows that the Fe(II) is in a low-spin state. H₃ BPTC⁴⁻ acts as a counter-ion in this complex. In [Cu(phen)(BPTC)_0.5 · H₂O] · H₂O (2), the central Cu(II) is five-coordinated in a square-pyramidal geometry. The ligand BPTC⁴⁻ is centrosymmetric and the four deprotonated carboxylic groups of BPTC⁴⁻ are coordinated to four different copper ions to form a 1D ladder complex indicating a comparatively strong coordination. In [Ni₃(phen)₃(BPTC)_1.5(H₂O)₅] · 4H₂O (3), all nickel(II) atoms are in an octahedral coordination environment. There are two different BPTC⁴⁻ ligands; one is centrosymmetric and the other is asymmetric. Metal ions are linked through fully deprotonated BPTC⁴⁻ ligands to form a 2D metal-organic sheet. [Cd(phen)(BPTC)_0.5] · H₂O (4) has a 3D metal-organic framework. TG, IR, and fluorescence data for the complexes are presented.     

Three silver coordination polymers constructed from 4,4′-bipyridine-like ligands and 2,5-thiophenedicarboxylic acid: crystal structures and photocatalytic performances

Transition Metal Chemistry - Three coordination polymers (CPs), formulated as [Ag(bpy)]2(tdc)·4H2O (BUC-78), [Ag(bpe)]2(tdc)·6H2O (BUC-79) and [Ag(bpp)]2(tdc)·8H2O (BUC-80) have been...     

Syntheses,crystal structures,and characterization of three metal–organic complexes with 2,2′-biphenyldicarboxylic acid and phenanthroline ligands

Three complexes constructed with 2,2′-biphenyldicarboxylic acid, multidentate nitrogen donors, and metal salts, {[Cd(2,2′-dpdc)(tppp)(H₂O)]₂?·?2H₂O} _n (1), {[Pb(2,2′-dpdc)(pyphen)]₂} _n (2), and {[Pb(2,2′-dpdc)(dppz)]} _n (3) (H₂dpdc = 2,2′-diphenyldicarboxylic acid; tppp = 4-(1H-1,3,7,8-tetraazacyclopenta[l]phenanthren-2-yl)phenol; pyphen?=?pyrazino[2,3-f]-[1,10]phenanthroline; and dppz = dipyrido[3,2-a:2′,3′-c]phenazine), are synthesized under hydrothermal conditions. These complexes are characterized by single-crystal X-ray diffraction, elemental analysis, IR, TGA, and photoluminescence. In 1, two 2,2′-dpdc ions bridge two Cd(II) ions to form an isolated cluster with Cd?···?Cd distance of 5.023(4)?Å. These clusters are further linked by intermolecular hydrogen bonds, yielding a 2-D supramolecular structure. Complex 2 contains two crystallographically independent Pb(II) ions in the asymmetric unit. Pb1 ions are bridged by 2,2′-dpdc anions to form a chain along the x-axis. Two Pb2 ions are coordinated by two 2,2′-dpdc anions and two pyphen ligands to form a cluster. These clusters are linked by π–π interactions to yield a 1-D supramolecular chain along the y-axis. In 3, neighboring Pb(II) atoms are bridged by 2,2′-dpdc anions to form a 1-D chain structure. Further, the chains are linked into a 3-D supramolecular network through aromatic π–π interactions.     

Synthesis,crystal, and molecular structure of coordination polymers constructed by self-assembly of NiN<Subscript>4</Subscript> cores with 2,2′-iminodibenzoate and nitroprusside ions

Two coordination compounds of compositions [Ni(L¹)(idba)(H₂O)]·1.5 H₂O (1) and [Ni(L²)Fe(CN)₅NO]·C₂H₅OH (2) where L¹ is N, N′-bis(3-aminopropyl)ethylenediamine, L² is 2,12-dimethyl-3,7,11,17-tetraazabicyclo[11.3.1]heptadeca-1(17),2,11,13,15-pentaene, and idba^2? is 2,2′-iminodibenzoate have been synthesized and characterized by elemental analysis, IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. Complex 1 crystallizes in the monoclinic space group P2₁/n (No. 14) with a=9.810(2) Å, b=10.230(2) Å, c=25.350(5) Å, V=2543.6(9) Å³, Z=4, and R=0.0727. The nickel atom is six-coordinated by four N atoms of amine and two O atoms of water and idba^2?. The molecular packing of the complex comprises of an infinite one-dimensional layered network in which the molecules in the crystal are held together by a system of hydrogen bonding. Complex 2, however, crystallizes in the space group C2/c (No. 15) of the monoclinic system with a=19.7990(4) Å, b=14.9440(3) Å, c=19.8800(3) Å, V=5115.90(17) Å³, Z=4, and R=0.0540. The Ni ion in compound 2 has a slightly distorted octahedral arrangement of the N₄ donor atoms of primary ligand L² and two N-donor atoms of the secondary nitroprusside ligand. The structure of 2 displays an extended one-dimensional network formed by linear [—Ni—NC—Fe—CN—] units. A cyclic voltammetric study shows that compound 1 undergoes a quasireversible oxidation attributable to Ni²⁺ → Ni³⁺ in the range 300–420 mV vs SCE.     

Modification of the structure and magnetic properties of fumarato-bridged Mn coordination polymers through different dimethyl-2,2′-bipyridine co-ligands

Manganese coordination polymers {Mn(fum)(5dmb)(H₂O)₂} _n (1) and {[Mn₂(fum)₂(4dmb)₂]·H₂O} _n (2) (fum = fumarato; 5dmb = 5,5′-dimethyl-2,2′-bipyridine; 4dmb = 4,4′-dimethyl-2,2′-bipyridine) were obtained from one-pot, solution reactions under ambient conditions. The fum ligand acquires different coordination modes in the presence of the different dmb ancillary ligands, promoting distinctive crystal structures, including divergent dimensionalities. Thus, X-ray single-crystal data reveal that complex 1 crystallizes in a monoclinic system with C2/c space group and forms an infinite one-dimensional polymer. The Mn(II) center is six-coordinated and displays a distorted octahedral configuration. In addition, the solid-state self-assembly of the polymeric structure of 1 gives rise to a two-dimensional (2D) supramolecular framework, mainly through hydrogen bonding. In contrast, complex 2 crystallizes in a monoclinic system with a Cc space group and forms an infinite 2D coordination polymer having dinuclear units. The Mn(II) center has a distorted octahedral configuration. The thermal stabilities of both coordination polymers were investigated. Variable-temperature magnetic measurements show that complex 1 is paramagnetic, while complex 2 exhibits weak antiferromagnetic coupling between adjacent Mn(II) centers.     

Synthesis and characterization of chiral copper(ii) coordination polymers with 4,4´-bipyridine and lactic acid derivatives

Russian Chemical Bulletin - Chiral 2D and 3D metal-organic coordination polymers [Cu2(bpy)2(Hdml)2(HCOO)]-(HCOO)·2H2O (1) and [Cu(bpy)(Hphl)(HCOO)]·H2O (2) were synthesized by heating a...