Hydrothermal synthesis, crystal structure and properties of Ag(I)-4f compounds based on 1H-benzimidazole-5,6-dicarboxylic acid

Seven novel heterometallic coordination polymers [CeAg(Hbidc)(2)(H(2)O)(2)] (1) and [LnAg(Hbidc)(2)]·3(H(2)O)[Ln = Sm (2), Gd (3), Tb (4), Dy (5), Ho (6), Er (7), H(3)bidc = 1H-benzimidazole-5,6-dicarboxylic acid] have been synthesized under hydrothermal conditions and characterized by elemental analysis, FT-IR, TG analysis, and single crystal X-ray diffraction. X-Ray analysis revealed that the seven complexes present two different types of three-dimensional (3D) structures. Complex 1 crystallized in an orthorhombic manner having a Pna2(1) space group, consisting of a 3D framework with a 1D heterometallic chain. Polymers 2-7 are isostructural and crystallized in an orthorhombic fashion having a Pccn space group existing of a two-fold interpenetrating 3D framework. The luminescence properties and the magnetic properties of all polymers were investigated.     

Copper(II) coordination frameworks with 1H-benzimidazole-5,6-dicarboxylic acid: syntheses,crystal structures and magnetic properties

Cu(II) polymers of Hbidc (1H-benzimidazole-5,6-dicarboxylate), namely [Cu₂(Hbidc)₂(H₂O)₄·3H₂O] _n (1) and [Cu(Hbidc)] _n (2), were synthesized under hydrothermal conditions by variation of the reaction temperature and characterized by physico-chemical, spectroscopic and single-crystal X-ray diffraction studies. At temperatures from 100 to 170 °C, we only obtained the 2-D structure compounds 1 and 2, in which the bridging mode of the Hbidc ligand increases from μ ₃ to μ ₅ and the number of water ligands decreases to 0. Both compounds have 3-D supramolecular architectures extended by hydrogen bonding and π–π interactions between the adjacent layers. Magnetic studies revealed that compound 1 shows weak antiferromagnetic properties and compound 2 exhibits ferromagnetic coupling between the two Cu(II) ions in the dimeric units.     

Hydrothermal synthesis, crystal structures, and properties of two Co(II) complexes based on 4-bromoisophthalic acid and N-donor ligands

Two new Co(II) complexes, [Co₂(H₂O)(Bipy)₂(Bript)₂] _n (I) and [Co(H₂O)(Phen)(Bript)] · H₂O (II), where H₂Bript = 4-bromoisophthalic acid, Bipy = 2,2??-bipyridine, and Phen = 1,10-phenanthroline, have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. Complex I has binuclear units in which two Co²⁺ ions are bridged by two carboxylate groups and a coordinaiod-water molecule, and the binuclear units are connected by Bript to generate a 1D helical chain. These 1D helical chains are further linked by ????? stacking interactions to form a 3D supramolecular network, while complex II has a 2D layer motif. In I and II, there exists extensive hydrogen bonding interactions. The thermal behavior of the two corresponding complexes have briefly been investigated.     

New copper(II) complexes including pyridine-2,5-dicarboxylic acid: synthesis,spectroscopic, thermal properties,crystal structure and how these complexes interact with purified PON 1 enzyme

We report the synthesis of two square-pyramidal copper(II) complexes, [Cu(2,5-pydc)(2-aepy)(H₂O)]·H₂O, 1, and [Cu(2,5-pydc)(2-ampy)(H₂O)]·H₂O, 2 (2-aepy = 2-(aminoethyl)pyridine, 2-ampy = 2-(aminomethyl)pyridine, 2,5-pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid). The synthesized complexes have been characterized by X-ray diffraction, FT-IR, elemental, and thermal analysis techniques. The crystal structure of 1 was established by X-ray analysis. Powder X-ray diffraction analysis showed that the complexes are pure. The inhibition of human serum paraoxonase 1 (PON 1, EC 3.1.8.1) enzyme with these complexes were investigated. We used diethyl 4-nitrophenyl phosphate as a substrate to measure the paraoxonase activity of PON 1 enzyme spectrophotometrically. Complexes 1 and 2 decreased the in vitro PON 1 activity with different inhibition mechanisms. Complexes 1 and 2 inhibited paraoxonase activity of this enzyme as competitively and noncompetitively, respectively.     

Four Ln(III) coordination polymers based on 1H-benzimidazole-5,6-dicarboxylate ligand: Synthesis, crystal structure, and luminescence

Four Ln(III) coordination polymers, [La₂(HBidc)₃(H₂O)] _n (I), [Pr₂(HBidc)₃(H₂O)] _n (II), [Sm₂(HBidc)₃(H₂O)] _n (III), and [Gd₂(HBidc)₃(H₂O)] _n (IV), were synthesized hydrothermally by treating Ln(NO₃)₃ · 6H₂O, NaOH, and H₃Bidc (H₃Bidc = 1H-benzimidazole-5,6-dicarboxylic acid) at 180°C and characterized by elemental analysis, IR spectra, and single-crystal X-ray structure analyses. Complexes I–IV are isostructural, and each complex contains two crystallographically independent Ln(III), one is seven-coordinated, while the other is eight-coordinated. X-ray crystallography reveals that the complex consists of 3D frameworks with the (3⁴·4⁴·5²·6⁶·7¹⁰·8·9)(3·4·5)(3·4·5) topology. Furthermore, the photoluminescence properties of III has been studied.     

Two dinuclear copper(II) complexes based on 5,6-dimethylbenzimidazole ligands: synthesis, crystal structures, and catalytic properties

Two new dinuclear copper(II) complexes, Cu₂(L1)₄(mal)₂(H₂O)₂ (1) (L1 = 5,6-dimethylbenzimidazole, mal = malonate), Cu₂(L2)₂(pydca)₂·4H₂O (2) (L2 = 1,5-bis(5,6-dimethylbenzimidazole)pentane, pydca = pyridine-2,6-dicarboxylate) have been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. The Cu(II) atoms in 1 and 2 both have square pyramidal coordination geometry. In 1, the two similar mononuclear structures are linked by π–π stacking as well as multiple hydrogen bonding interactions to generate a 2D supramolecular layer, while complex 2 is connected with two different patterns of π–π stacking and hydrogen bonding interactions into a 3D supramolecular network. The catalytic activities of 1 and 2 for the degradation of Congo red have been investigated.     

Solvothermal synthesis, crystal structure, and properties of lanthanide-organic frameworks based on thiophene-2,5-dicarboxylic acid

A series of lanthanide-organic framework coordination polymers, {[La(2)(TDC)(2)(NO(3))(H(2)O)(4)](OH)·5H(2)O}(n) (1) and [Ln(TDC)(NO(3))(H(2)O)](n) (TDC = thiophene- 2, 5- dicarboxylic acid; Ln = Nd(2), Sm(3), Eu(4), Gd(5), Tb(6), Dy(7), Ho(8), Er(9), Yb(10)) have been synthesized by solvothermal reaction and characterized by elemental analysis, FT-IR, TG analysis, single-crystal X-ray diffraction and power X-ray diffraction. The single-crystal X-ray diffraction analysis results show that 1 displays a 3-D porous framework with (3,7)-connected {4(10).6(11)}{4(3)} topology. The compounds 2-10 crystallized in the same P2(1)/c space group and exhibits a (3,6)-connected {4.6(2)}(2){4(2).6(10).8(3)} topology, Right-handed and left-handed helical chains coexist in the 2-D layer structure. The luminescence properties of 2-10 and the magnetic properties of 5,7,8,9 were investigated.     

Hydrothermal synthesis,crystal structure and magnetic properties of a copper(II) phosphonate

The treatment of 3-ammonium-1-hydroxypropylidene-1,1′-bisphosphonate (H₇ahdp) and 4,4′-bipy with CuCl₂?·?2H₂O resulted in a metal phosphonate [Cu(H₅ahdp)?·?H₂O] _n . Its crystal structure has been characterized by single X-ray crystallography. Although there is no 4,4′-bipy in the lattice structure, it plays a very important role in forming the one-dimensional chain of the polymer. Hydrogen bonds link the chains into a 3D network. The dinuclear secondary building units are observed in the compound. The determination of variable-temperature magnetic susceptibilities (5?～?300?K) shows weak intrachain antiferromagnetic coupling between copper(II) centers. The magnetic data were fitted to the appropriate equations derived from the Hamiltonian H?=??2JS ₁ S ₂, giving the parameter J?=??25.78?cm^?1. Its thermal properties were also investigated.     

Two complexes based on 1H-1,2,3-triazole-4,5-dicarboxylic acid: hydrothermal synthesis,crystal structures and spectral properties

[Zn₃(tda)₂(bipy)₂(H₂O)_2?·?4H₂O] _n (1) and [Co₂(Htda)₂(H₂O)₆·5H₂O] (2) have been synthesized and characterized structurally by X-ray diffraction, where H₃tda?=?1H-1,2,3-triazole-4, 5-dicarboxylic acid and 2,2′-bipy?=?2,2′-bipyridine. Their solid-state structures have been characterized by elemental analysis and IR spectroscopy. The molecular unit of 1 consists of two crystallographically unique Zn(II) ions assuming different coordination geometries, the tda^3? exhibits a hexadentate binding mode chelating three Zn(II) ions; neighboring Zn–Zn distances through tda^3? bridges are 5.910(6), 5.888(5), and 6.279(3)?Å, respectively. In 2, two neighboring Co(II) ions are bridged by two Htda^2? ligands, forming a binuclear structure, with Co–Co distance of 4.091?Å and is further linked to generate a 3-D structure via hydrogen bonds. Fluorescent of 1 was investigated.     

Extended triple-bridged Ni(II)- and Co(II)-hydroxamate trinuclear complexes: synthesis, crystal structures, and magnetic properties

Crystal structures of new trinuclear complexes [Ni 3(mu-OAc F) 4(mu-AA) 2(tmen) 2], [Ni 3(mu-OAc F) 4(mu-BA) 2(tmen) 2], and [Co 3(mu-OAc F) 4(mu-BA) 2(tmen) 2] have been determined (OAc F = CF 3COO (-), AA = acetohydroxamate anion, BA = benzohydroxamate anion, tmen = N, N, N', N'-tetramethylethylenediamine). In each structure, the metal ions have distorted octahedral coordination and are triply bridged by one hydroxamate and two trifluoroacetate bridges. Magnetic properties of these compounds and of relative [Co 3(mu-OAc F) 4(mu-AA) 2(tmen) 2] were studied by susceptibility and magnetization measurements. It was shown that for nickel trimers the intramolecular magnetic coupling is weak ferromagnetic in the case of the complex with the AA group, and there is nearly no coupling in the case with BA group. Rather large zero field splitting was obtained for the distorted octahedral environments of the terminal nickel ions. The cobalt trimers were additionally studied by magnetic circular dichroism (MCD) measurements. The exchange interaction of the cobalt complexes is antiferromagnetic.     

Hydrothermal synthesis,crystal structure and antibacterial studies of nickel(II) and manganese(II) complexes with ciprofloxacin

Hydrothermal treatments of ciprofloxacin with Ni(NO₃)₂·6H₂O and Mn(ClO₄)₂·6H₂O yield two metal complexes: [Ni(H-cip)₂(H₂O)₂](NO₃)₂·2H₂O (1) and [Mn(H-cip)₂(H₂O)₂] (ClO₄)₂·2H₂O (2), confirmed by elemental analysis, IR and single crystal X-ray diffraction analyses. Complexes 1 and 2 were screened for antibacterial activity against Staphylococcus aureas, E. coli, Pseudomonas aeruginos and Candidaalbicans.     

Synthesis,properties, and X-ray crystal structures of two Ag(I) complexes with 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid

Two 1-D and 3-D Ag(I) complexes involving 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid (H₃PIDC) have been characterized by infrared spectrum, elemental analysis, and single-crystal X-ray diffraction. [Ag₂(HPIDC)]_n (1), synthesized under hydrothermal conditions, gave a 3-D framework; [Ag₂(HPIDC)(MBI)]_n (2) (MBI?=?2-methyl-1H-benzo[d]imidazole), with MBI as the second ligand, gave a 1-D zigzag chain and further formed a 3-D supramolecular structure through π···π interactions. The most interesting structural features of these complexes are the presence of C–H···Ag hydrogen bonding interactions and Ag···C weak interactions between the Ag centers and H₃PIDC. Luminescence indicates that 2 has significantly stronger fluorescent emissions than 1 in the solid state at room temperature.     

Synthesis, crystal structure, and magnetic properties of oxime-bridged polynuclear Ni(II) and Cu(II) complexes

Two new polynuclear complexes [Ni6(amox)6(mu6-O)(mu3-OH)2](Cl2).6H2O and [Cu3(amox)3(mu3-OH)(mu3-Cl)](ClO4).4H2O (amox- = anion of 4-amino-4-methyl-2-pentanone oxime) have been synthesized and characterized structurally and magnetically. The Ni(II) complex contains a novel Chinese-lantern-like Ni6 cage centered by an oxo ion. It contains the nearest octahedral Ni(II)...Ni(II) separation (<2.8 A) and exhibits strong antiferromagnetic properties. The Cu(II) complex has a cyclic trinuclear copper(II) core bridged by both mu3-OH(-) and mu3-Cl(-) ions. The magnetic susceptibilities of both antiferromagnetic complexes were fitted by using approximate models.     

Two copper(II) complexes with 4-benzoylpyridine ligand: synthesis, crystal structure and luminescent properties

Two new copper(II) complexes Cu(NCS)2(4-Bzpy)2 (1) and Cu(NO3)2(4-Bzpy)4 (2) (4-Bzpy=4-benzoylpyridine) have been synthesized and characterized by IR, UV, elemental analysis and X-ray crystallography. Cu(II) atom has a square planar environment for 1 and an distorted octahedral environment for 2, respectively. In solid state there are C-H?π interactions and C-H?S hydrogen bonds between adjacent molecules in complex 1. The molecule of complex 2 is further connected by multiform π-π interactions, C-H?π interactions and C-H?O hydrogen bonds to form a three-dimensional supramolecular structure. The luminescent properties of the complexes 1 and 2 were both investigated in H2O solution and in solid state at room temperature, respectively.     

Synthesis and crystal structures of two Zinc(II) complexes with 4-hydroxypyridine-2,6-dicarboxylic acid

Two new complexes [Zn(Hpda)(Bth-6)]_2n (I) and [Zn(Hpda)₂] · 2(H-Bpe) (II) (HpdaH₂ = 4-hydroxypyridine-2,6-dicarboxylic acid, Bth-6 = 1,6-bis(1,2,4-triazol-1-yl)hexane, Bpe = 1,2-bi(4-pyridyl)ethene) have been synthesized and characterized structurally. Their X-ray crystal structures show that the two complexes belong to a monoclinic system; space group P2₁/n with a = 11.9328(12), b = 20.975(2), c = 17.1544(17) Å; β = 91.406(2)°, Z = 4 for I; space group P2₁/c with a = 12.7150(19), b = 14.000(2), c = 22.171(3) Å; β = 96.481(2)°, Z = 4 for II. Compound I possesses a one-dimensional (1D) zigzag chain structure, each zinc(II) ion is five-coordinated with a distorted triangle bipyramid geometry. Compound II is discrete mononuclear species, in which the zinc(II) ion is six-coordinated with a distorted octahedral geometry. The [Zn(Hpda)₂]^2? units are connected one-dimensional chain by the intermolecular hydrogen bonds.     

Hydrothermal syntheses,crystal structures and properties of two cobalt(II) complexes constructed from 5-(isonicotinamido)isophthalic acid

Two Co(II) complexes, [Co(INAIP)(dib)]·4H₂O and [Co(INAIP)(phen)(H₂O)]·H₂O have been synthesized by the reaction of 5-(isonicotinamido)isophthalic acid (H₂INAIP) and CoSO₄·7H₂O, as well as N-donor ligands, namely 1,4-di(1-imidazolyl)benzene (dib) and 1,10-phenanthroline (phen) under hydrothermal conditions. Single-crystal X-ray diffraction analysis indicates that [Co(INAIP)(dib)]·4H₂O has a two-dimensional (2D) double-layer network structure with a (4, 4) topology, while [Co(INAIP)(phen)(H₂O)]·H₂O displays a one-dimensional chain structure, extending to a 2D net through the π–π interactions. In addition, the photoluminescence and degradation of methyl orange in a Fenton-like process using the complexes as catalysts were investigated.     

Four Ni(II), Co(III), Cd(II) complexes based on 5-(pyrazol-1-yl)nicotinic acid: synthesis,X-ray single crystal structure,in vitro cytotoxicity,apoptosis and molecular docking studies

We have developed complexes [Ni₂(L)₂(H₂O)₄]_n (1), [Co₂(L)₂(H₂O)₄]_n (2), [Cd₂(L)₂(H₂O)₂Cl₂]n (3) and [Cd₂(L)₂(H₂O)₂]_n (4), where HL = 5-(pyrazol-1-yl) nicotinic acid. All complexes were characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction, showing monoclinic crystal lattice with space group P2₁/c (1), P2₁/c (2), P2₁/c (3), and triclinic crystal lattice with space group P-1 (4), separately. In vitro antitumor screening (MTT method) revealed that 3 exhibited better inhibitory activities than the commercial anticancer drug cisplatin against HeLa tumor cell lines, with IC50 values 9?±?2. The bindings of these complexes with Fish Sperm DNA were measured by electronic absorption spectra and fluorescence spectroscopy, showing K_sq 0.1867 (1), 0.1589 (2), 0.2332 (3), and 0.1411 (4), with the binding affinities ranked 3?>?1 > 2?>?4. The experimental result showed that these complexes could bind DNA via intercalation. The ability of 1–4 to cleave the pBR322 plasmid DNA was demonstrated by gel electrophoresis assay. The experiment verified that these complexes could induce DNA damage. In addition, flow cytometric analysis showed that 1–4 induced apoptosis of HeLa tumor cell lines; as time increases, the apoptotic impact becomes increasingly significant. The potential of 1–4 as anticancer agents were examined using molecular docking of the complexes with DNA.

     

A twofold interpenetrated 3-D Cu(II) coordination polymer based on 5-(pyridin-4-yl)isophthalic acid: synthesis,crystal structure,and magnetic properties

A new copper(II) coordination polymer, [Cu(PIA)·2H₂O]_n (1) [H₂PIA = 5-(pyridin-4-yl)isophthalic acid], has been synthesized and characterized by elemental analysis, IR spectroscopy, TGA, powder, and single-crystal X-ray diffraction. Structural analysis shows that each PIA^2? in 1 bridges three Cu(II) ions, and likewise each Cu(II) ion connects to three PIA^2? ligands, giving a 3-D framework with utp topology and left-/right-handed helical channels. Interestingly, two such identical frameworks interlock with each other to generate a twofold interpenetrated structure that is stabilized by hydrogen bonding and π–π interactions. In addition, the thermal stability and the magnetic properties of 1 have been investigated.