Two cobalt(II) coordination polymers based on carboxylate ligand: Preparation,crystal structures and magnetic properties

Two new coordination polymers, [Co₂(L)_1.5(OH)(H₂O)₂]·2H₂O (1) and [CoL(bpp)] (2) (H₂L = 2,5-dibenzoylterephthalic acid and bpp = 1,3-bis(4-pyridyl)propane), have been synthesized and characterized by elemental analyses, IR spectra, and thermogravimetric analyses. Their structures were determined by single crystal X-ray diffraction analyses. Complex 1 exhibits a 3D framework assembled from tetra-nuclear cobalt-oxygen bridged by carboxylic O atoms with a (4¹²·6³) topology. Complex 2 possesses a 2D layered structure which extends into a 3D architecture via C–H···π interaction between propane proton and the phenyl ring or pyridine ring of an adjacent sheets. Furthermore, the magnetic properties of them are discussed.     

Hetero-bimetallic 2D coordination network constructed by azacrown ether carboxylic acid with lanthanide(III) and sodium ions

Two lanthanide-based coordination polymers [Na₃La(L)Cl·(H₂O)₆]·NO₃ (La-L) and [Na₃Eu(L)Cl·(H₂O)₆]·NO₃ (Eu-L) were newly synthesized by reaction of an azacrown ether carboxylic acid ligand H₄L (4,7,13,16-tetracarboxymethyl-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane) with La(III)/Eu(III). Complexes La-L and Eu-L exhibited two-dimensional (2D) coordination architectures built up by Ln–L coordinating subunits and one-dimensional (1D) Na–O bridging chains. Four versatile coordination modes of carboxyl groups and Na–O coordination bi-chains linked by novel μ-O bridges (μ2-O and μ3-O) were demonstrated in the structure. Photoluminescence spectra of Eu-L were investigated to reveal characteristic emissions of Eu(III). This is the first example of hetero-bimetallic complex of the tetraazacrown ether ligand with lanthanide and sodium ions.     

One-dimensional helical Cu(II) coordination polymer: Synthesis,structures, and properties

One new Cu(II) coordination polymer (1) based on 6,6′-dihydroxy-2,2′-bipyridine (H₂dhbp) was successfully prepared, with the formula of [Cu(μ₂-OH)(Hdhbp)]_n (1). Single-crystal X-ray analysis shows that compound 1 crystallizes in orthorhombic chiral space group P2₁2₁2₁ and exhibits a left-handed (L) helical [Cu(μ₂-OH)]_n-chain. Luminescence of 1 exhibits a broad emission around 440 nm, attributing to the metal to ligand charge transfer (MLCT). Magnetic susceptibility shows antiferromagnetic coupling within compound 1. Cyclic voltammetry (CV) experiments indicate a potential water oxidation electrocatalyst.     

A 3D Gd–Ag coordination polymer constructed from pyridine-3,5-dicarboxylic acid: Synthesis, crystal structure and magnetic properties

A novel heterometallic coordination polymer, [AgGd(PDC)₂]·2H₂O (1) (H₂PDC = pyridine-3,5-dicarboxylic acid), have been synthesized under hydrothermal conditions, and characterized by elemental analysis, IR, thermogravimetric analysis and single-crystal X-ray diffraction. Complex 1 features an unusual three-dimensional network structure in which infinite gadolinium-carboxylate chains are linked by [Ag(PDC)₂]³⁻ metalloligands to form a mixed-metal coordination network. Moreover, the luminescent properties and magnetic properties of 1 have also been investigated.     

Syntheses,structures and properties of three dumbbell-shape Cadmium (II) complexes constructed by a tripodal ligand via hydrogen-bonding assembly

Three hydrogen-bonding frameworks based on NH⋯N and NH⋯O Hbond linkages have been synthesized and structurally characterized by using ntb (tris(2-benzimidazoylmethyl)amine) to react with two Cd(II) salts in the presence of dysfunctional bridging spacers of NaN3, 4'4-bipy and H2tpa (terephthalic acid) respectively. The building blocks of three complexes exhibit dumbbell-shape which stacks each other in the lattice leading to three 3D hydrogen-bonding frameworks with diversiform topology net of distorted NaCl net, (4,4) layer and 4²⁴ · 6⁴ net.     

Synthesis,structures, and photoluminescent properties of two uranium complexes constructed by a flexible zwitterion ligand

Two novel uranium complexes were constructed by using a tripodal flexible zwitterion ligand 1,1′,1″-(2,4,6-trimethylbenzene-1,3,5-triyl)-tris(methylene)-tris(pyridine-4-carboxylic acid) trichlorine (H₃LCl₃). Reaction of uranyl acetate dihydrate and H₃LCl₃ in aqueous solution affords (UO₂)₄L₂Cl₄(μ₃-O)₂^.4H₂O (1), which contains tetranuclear motifs, resulting in the two dimensional structure. UO₂L₂^.2NO₃^.H₂O (2) obtained via the reaction of H₃LCl₃ and uranyl nitrate hexahydrate, which displays a three dimensional structure. The structures were detected by single crystal X-ray crystallography, elemental analysis (EA), infrared (IR) spectroscopy, and thermogravimetric analysis (TGA). Furthermore, luminescent properties were also investigated.     

Temperature/anion-dependent self-assembly of Co(II) coordination polymers based on a heterotopic imidazole-tetrazole-bifunctional ligand: Structures and magnetic properties

Reactions of Co(II) with 5-(3-(1H-imidazol-1-yl)phenyl)-1H-tetrazolate (HIPT) resulted in three Co(II) coordination polymers (CPs), namely, {[Co(IPT)₂(H₂O)₂]·2H₂O}_n (1), [Co(IPT)₂]_n (2), and {[Co₃(IPT)₂(CH₃COO)₂(OH)₂(H₂O)₂]·2H₂O}_n (3). Compound 1 that obtained from CoCl₂·6H₂O at 120 °C is a 2D network based on Co(II) ions and μ₂-IPT⁻ ligands. Compound 2 that obtained from CoCl₂·6H₂O at 170 °C exhibits a 3D framework based on linear trinuclear Co(II) SBUs and features a pcu network topology. Compound 3, which obtained by using Co(Ac)₂ as salt, displays a 2D network based on 1D SBUs. The structures of compounds 1–3 are dependent on the temperatures and inorganic anions. The magnetic properties of compounds 2–3 were also explored.     

Study on macromolecular lanthanide complexes (V): Synthesis,characterization, and fluorescence properties of lanthanide complexes with the copolymers of styrene and acrylic acid

In this study, the luminescent macromolecular lanthanide complexes Ln‐PSt/AA (Ln = Eu and Tb; St = styrene; AA = acrylic acid) have been synthesized, and an extensive characterization has been carried out by means of elemental analysis, FTIR, thermal analysis, and fluorescence determination. The results showed that the carboxylic groups on the chain of the polymers acted as bidentate ligands coordinated to lanthanide ions; and the coordination degree of ? COO^?/Ln³⁺ in the macromolecular complexes was closely dependent on both the pH value of the solution and the molar ratio of St to AA in the polymeric ligands. Thermal analysis manifested that these Ln‐PSt/AA (Ln = Eu and Tb) complexes had high thermal stability and solvent resistance, and these macromolecular complexes were highly crosslinked. The fluorescence determination indicated that Ln‐PSt/AA complexes could emit characteristic fluorescence with comparatively high brightness and good monochromaticity, and the fluorescence intensity changed with increasing lanthanide ions content. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis, structures, and photoluminescent properties of 3D lanthanide coordination polymers with rare (4,5)-connected topology

Three lanthanide coordination polymers, [Ln(Hpdc)(ox)_0.5(H₂O)₂]·H₂O (Ln = Nd(1), Eu(2), Er(3)) (H₃pdc = 3,5-pyrazoledicarboxylic acid, ox = oxalate), have been synthesized by the hydrothermal reaction of lanthanide nitrates, 3,5-pyrazoledicarboxylic acid, and oxalic acid (H₂ox) and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies indicate that complexes 1–3 are isomorphous and exhibit three-dimensional metal–organic frameworks with uncommon (4,5)-connected topology, which contain open channels occupied by the lattice water molecules. The photoluminescent properties of complex 2 were also studied.     

Syntheses,structures and magnetic properties of a series of lanthanide complexes based on p-methoxybenzoic acid

A new series of lanthanide metal complexes [Ln(L)₃]_n (L = p-methoxybenzoic acid, Ln = Pr 1, Eu 2, Tb 3, Dy 4, Ho 5, Er 6, Yb 7) have been synthesized under hydrothermal conditions. Single-crystal X-ray diffraction measurements reveal that these compounds are isostructural, crystallizing in the monoclinic space group P2₁/c and giving 1D chain structures. Magnetic studies reveal antiferromagnetic behavior for complexes 1, 3, 5 and 6, ferromagnetic behavior for complex 4 and spin-canting behavior for 7.     

Three Cu(II) coordination polymers with novel bi-triazole ligand: Synthesis,structure and EPR properties

Three Cu(II) coordination polymers: [Cu(XL)(NO₃)₂]_n (1), {[Cu(XL)(4,4′-bpy)(NO₃)₂]·CH₃CN}_n (1a) and {[Cu(XL)₃](NO₃)₂·3.5H₂O}_n (2) have been synthesized mainly based on a novel bi-triazole ligand N,N′-bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxdiimide bi(1,2,4-triazole) (XL) and characterized by X-ray crystallography, EPR spectra, elemental analyses, FT-IR spectra and PXRD patterns. Structure analyses reveal that compounds 1 and 1a exhibit 1D chains, and compound 2 features a 2D cationic framework. Additionally, the Cu(II) ions with various coordination environment in compounds 1, 1a and 2 exhibit different EPR properties.     

Linear trinuclear manganese(II) complexes: crystal structures and magnetic properties

Two new trinuclear manganese(II) complexes, [Mn₃(O₂CCH(CH₃)₂)₆(N–N)₂] (N–N is 1,10′-phenanthroline (1) and 2,2′-bipyridine (2)) have been prepared and fully characterized. Single crystal X-ray diffraction analysis confirmed a linear arrangement of three Mn(II) centers bridged by six isobutyric carboxylate groups. The magnetic measurements showed that both complexes exhibit an S_T = 5/2 spin ground state induced by antiferromagnetic interactions between the Mn(II) sites: J/k_B = −2.31(2) and −2.67(2) K for 1 and 2, respectively.     

Synthesis,crystal structures and properties of two Pd(II) and Pt(II) complexes involving 3,5-diphenylpyrazole and NO2 donor ligands

A pyrazolate bridged binuclear Pd(II) complex [Pd₂(μ-dppz)₂(Hida)₂] · CH₃OH · 2H₂O (1) (dppz = 3,5-diphenylpyrazolate) with monoprotonated iminodiacetate (Hida) and a mononuclear Pt(II) complex containing Hdppz and 2,6-pyridinedicarboxylate (2,6-dipic) [Pt(Hdppz)(2,6-dipic)] · CH₃OH (2) have been synthesized and characterized by elemental analysis, ¹H NMR, ESI-MS and single crystal X-ray diffraction studies. The molecular packing for 1 shows a 2D network while that for 2 constitutes a left-handed 1D helix. Moderate luminescence property and antimicrobial activity against Bacillus subtilis have been noted for both.     

Polycatenated (4, 4) lanthanide(III) coordination networks based on apidate: Synthesis,structure and properties

Three rare earth coordination polymers, {[Ln₂(μ₃-ADI)₂(μ₂-ADI)(H₂O)₄]·H₂O}_n (Ln = Tb, 1; Eu, 2; Er, 3; ADI = adipate), which show the inclined interpenetration of (4, 4) nets and bright luminescence, were isolated from H₂PDC-assisted (H₂PDC = pyridine-2,3-dicarboxylatic acid) hydrothermal reactions of H₂ADI and Ln₂O₃.     

Synthesis,structures, and luminescence of lanthanide coordination polymers constructed from benzimidazole-5,6-dicarboxylate and oxalate ligands

Three novel coordination polymers [(Eu₂(Hbidc)₂(ox)₂·(H₂O)₃] (1), [Tb₂(Hbidc)₂(ox)(H₂O)₂]·4H₂O (2), [Er₂(Hbidc)₂(ox)] (3) have been synthesized with hydrothermal reaction (H₃bidc = Benzimidazole-5,6-dicarboxylic acid, H₂ox = Oxalic acid) and characterized by elemental analysis, IR and X-ray single crystal diffraction. 1, 2 and 3 have the same crystal system of triclinic, but they exhibit different kinds of metal-organic framework structures. The luminescent properties of 1 and 2 were studied at room temperature.     

Novel lanthanide coordination polymers with Eu-compound exhibits warm white light emission: Synthesis,structure, and magnetic properties

Five two-dimensional lanthanide coordination polymers: [Ln₂(TDA)₃(bipy)₂(H₂O)₂]·bipy·2H₂O (Ln = Nd (1), Sm (2), Eu (3), Tb (4), Yb (5), TDA = thiophene-2,5-dicarboxylic acid anion, bipy = 2,2′-bipyridine) were fabricated and structurally characterized. Compounds 1–5 are isostructural belonging to the triclinic system with space group P-1. Luminescence analyses were performed on coordination polymers containing Eu^3 + and Tb^3 +, and compound 3 shows a warm white light emission upon excitation.     

1D chain lanthanide coordination polymers with 6-hydroxynicotinic acid: Crystal structures and luminescent properties

Four new lanthanide coordination polymers {[Ln(HL)₂(H₂O)₅] · HL ·  H₂O}_n (Ln = Sm for 1, Eu for 2, Tb for 3 and Dy for 4) (H₂L = 6-hydroxynicotinic acid) have been synthesized and characterized by elemental analysis, FT-IR spectra and X-ray single-crystal diffraction. They all exhibit 1D chain structure, which are further linked via hydrogen bonds to form 3D supramolecular architecture. Luminescent properties of these lanthanide coordination polymers are studied.     

Microporous coordination polymers of cobalt(II) and manganese(II) 2,6-naphthalenedicarboxylate: preparations, structures and gas sorptive and magnetic properties

Two isostructural coordination polymers M₃(NDC)₃(DMF)₄ (M = Co (1), Mn (2); H₂NDC = 2,6-naphthalenedicarboxylic acid; DMF = N,N′-dimethylformamide) were prepared through conventional and microwave-assisted solvothermal methods. Single crystal X-ray analysis indicated that both complexes crystallized in the monoclinic system with space group C2/c. Powder X-ray diffraction (PXRD) patterns of the bulk samples for the two complexes obtained from microwave-assisted solvothermal syntheses matched well with the simulated ones from the single crystal data as well as the ones prepared by conventional solvothermal method. These microporous cobalt(II) and manganese(II) coordination polymers undergo reversible structural change upon desolvating, giving stable microporous frameworks containing unsaturated metal sites, and resolvating. The desolvated complexes showed different nitrogen gas adsorption capabilities but very close hydrogen adsorption behaviors. Variable-temperature magnetic susceptibilities of 1 and 2 revealed the weak antiferromagnetic coupling between the adjacent metal ions bridged by carboxylate.     

Synthesis,crystal structures and cytotoxic activity of mononuclear nickel(II) and dinuclear zinc(II) complexes with ligand derived from S-benzyldithiocarbazate

Ni(L)₂ (1) and Zn₂(μ-OL)₂(L)₂ (2), (HL = S-benzyl-β-N-(2-bromobenzylidene) dithiocarbazate), were synthesized and characterized by elemental analysis and X-ray single-crystal diffraction analysis. 1 is a mononuclear neutral nickel(II) complex and the center nickel atom is chelated by donors of N₂S₂ possessing a distorted tetrahedral configuration, while in 2, the adjacent two complex molecules are linked through two O atoms to form a dimer and the center zinc atom is five-coordinate in a distorted trigonal–bipyramidal geometry. The cytotoxic activity study indicated that 2 showed potent cytotoxic activity against the human liver hepatocellular carcinoma (HepG2) cancer cell lines, with IC₅₀ 2.4 ± 0.2 μg·mL^− 1, which is slightly weaker than 5-fluoroacil (5-FU) (0.89 ± 0.21 μg·mL^− 1) as reference. A gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 plasmid DNA.