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1.
Four copper complexes with similar trinuclear copper units, [Cu6(Bmshp)2(SO4)2(H2O)7]·2H2O (1), [Cu3(Bmshp)(ClO4)2(H2O)4]·5H2O (2), [Cu3(Bmshp)(DMF)4(H2O)2]·H2O·2DMF·2ClO4 (3) and [Cu3(H2Bcshp)(ClO4)2(H2O)4]·3H2O (4) (H4Bmshp = 2,6-bis[(3-methoxysalicylidene)hydrazinocarbonyl]pyridine, H6Bcshp = 2,6-bis[(3-carboxylsalicylidene)hydrazinocarbonyl]pyridine), were synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. Due to the different anions, solvents and ligands used in the syntheses, complexes 14 exhibit diverse supramolecular structures constructed from the corresponding trinuclear copper units via H-bonds.  相似文献   

2.
A hetero-metal organic framework, [NaSr(HTiron)(H2O)5]·H2O (1) (Na2H2Tiron = 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium), has been synthesized under hydrothermal condition. The framework was characterized by elemental analysis, FT-IR spectroscopy, UV–Vis spectroscopy, thermal analysis, and single-crystal X-ray diffraction. It features a 3-D network structure with (42,124)(45,64,8)2(4)2 topology, constructed by HTiron3? ligands. Compared with the ligand, the photoluminescence emission of 1 bathochromically shifts and shows emission maximum at 497 nm at room temperature.  相似文献   

3.
An octahedral zinc(II) complex of 2,2′:6′,2″-terpyridine (Tpy) and pyridine-2,6-dicarboxylate (Pydc), [Zn(II)(Tpy)(Pydc)·4H2O] was synthesized and its structure was determined by a single-crystal X-ray diffraction. The ligand pyridine-2,6-dicarboxylate coordinated to the zinc(II) ion via two pairs of carboxylate oxygens and one nitrogen atom, whereas 2,2′:6′,2″-terpyridine also contributed three coordination bonds through its nitrogen atoms. [Zn(II)(Tpy)(Pydc)·4H2O] showed luminescence properties between 412 and 435 nm in DMSO. The solid-state octahedral geometry of [Zn(II)(Tpy)(Pydc)·4H2O] was also preserved in solution as confirmed by the observed UV λex = 346. Experimental and theoretical studies indicated that [Zn(II)(Tpy)(Pydc)·4H2O] interacted with amoxicillin. Density functional theory calculations at B3LYP/LanL2dz level of theory suggested that [Zn(II)(Tpy)(pydc)·4H2O] dimer interacts with (2S,5R,6R)-6-{[(2R)-2-amino-2-(4-hydroxyphenyl)-acetyl]amino}-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0]heptane-24-carboxylic acid (amoxicillin) via highest occupied molecular orbital and lowest unoccupied molecular orbital, π–π interaction, hydrogen bond interaction, and van der Waals forces, thus influencing [Zn(II)(Tpy)(Pydc)·4H2O] properties.  相似文献   

4.
Tellurium (IV) complexes with pyridine-2,6-dicarboxylate ligand were synthesized by slow evaporation from aqueous solutions yielding a new compound: [(C7H6NO4)2TeBr6·4H2O]. The structure of this compound was solved and refined by single-crystal X-ray diffraction. The compound is centrosymmetric P21/c (N°: 14) with the parameters a = 8.875(5) Å, b = 15.174(5) Å, c = 10.199(5) Å, β = 94.271° (5) and Z = 2. The structure consists of isolated H2O, isolated [TeBr6]2? octahedral anions and (pyridine-2,6-dicarboxylate) [C7H6NO4]+ cations. The stability of the structure was ensured by ionic and hydrogen bonding contacts (N–H?Br and O–H?Br) and Van-Der Walls interaction. The thermal decomposition of the compound was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The FTIR and Raman spectroscopy at different temperatures confirm the existence of vibrational modes that correspond to the organic, inorganic and water molecular groups. Additionally, the UV–Vis diffuse reflectance spectrum was recorded in order to investigate the band gap nature. The measurements show that this compound exhibits a semiconducting behavior with an optical band gap of 2.66 eV.  相似文献   

5.
Four macrocyclic Schiff-base cobalt complexes, [CoL1][NO3]2 · 3H2O, [CoL2][NO3]2 · 4H2O, [CoL3][NO3]2 · 4H2O and [CoL4][NO3]2 · 2H2O, were synthesized by reaction of salicylaldehyde derivatives with 1,4-bis(3-aminopropoxy)butane or (±)-trans-1,2-diaminocyclohexane and Co(NO3)2 · 6H2O by template effect in methanol. The metals to ligand ratio of the complexes were found to be 1:1. The Co(II) complexes are proposed to be tetrahedral geometry. The macrocyclic Co(II) complexes are 1:2 electrolytes as shown by their molar conductivities (ΛM) in DMF (dimethyl formamide) at 10?3 M. The structure of Co(II) complexes is proposed from elemental analysis, Ft-IR, UV–visible spectra, magnetic susceptibility, molar conductivity measurements and mass spectra. Electrochemical and thin-layer spectroelectrochemical studies of the complexes were comparatively studied in the same experimental conditions. The electrochemical results revealed that all complexes displayed irreversible one reduction processes and their cathodic peak potential values (E pc) were observed in around of ?1.14 to 0.95 V. It was also seen that [CoL1][NO3]2 · 3H2O and [CoL2][NO3]2 · 4H2O exhibited one cathodic wave without corresponding anodic wave but, [CoL3][NO3]2 · 4H2O and [CoL4][NO3]2 · 2H2O showed one cathodic wave with corresponding anodic wave, probably due to the presence of different ligand nature even if the complexes have the same N2O2 donor set. In view of spectroelectrochemical studies [CoL3][NO3]2 · 4H2O showed distinctive spectral changes in which the intensity of the band (λ = at 316 nm, assigned to n → π* transitions) decreased and a new broad band in a low intensity about 391 nm appeared as a result of the reduction process based on the cobalt center in the complex.  相似文献   

6.
In this study, an ionic complex of V(V) was synthesized by using ultrasonic method, and it was used as a precursor for production of a new catalyst for selective preparation of methylal or dimethoxymethane (DMM). By reaction between an ionic ligand [pyda.H2]2+[pydc]2? (LH2), (pyda.H2 = 2,6-pyridine diammonium and pydc = 2,6-pyridinedicarboxylate) and ammonium vanadate, the five coordinated V(V) complex, [pyda.H][V(pydc)O2], {2,6- diaminopyridinum 2,6-pyridinedicarboxylatodioxovanadate(V)}, VLH2 was synthesized. The prepared complex VLH2 was characterized by SEM, thermal analysis TGA/DTA, FT-IR spectroscopy and X-ray diffraction studies. The results showed that the yield of the reaction was increased up to 64%. The average particle sizes of the obtained complex VLH2 were about 50–60 nm. Also, the nano-catalyst of V2O5/Al2O3 was synthesized by impregnation method and was prepared as a nano-catalyst with average particles sizes of 50–60 nm, and its characterization was performed by XRD, EDX and SEM methods. Finally, the prepared catalyst was used to converting of methanol to methylal at different process conditions.  相似文献   

7.
Seven-coordinate Fe(III) complexes [Fe(dapsox)(H2O)2]+, where [dapsox = 2,6-diacetylpyridine-bis(semioxamazide)] is an equatorial pentadentate ligand with five donor atoms (2O and 3N), were studied with regard to their acid–base properties and complex formation equilibria. Stability constants of the complexes and the pK a values of the ligands were measured by potentiometric titration. The interaction of [Fe(dapsox)(H2O)2]+ with the DNA constituents, imidazole and methylamine·HCl were investigated at 25 °C and ionic strength 0.1 mol·dm?3 NaNO3. The hydrolysis constants of the [Fe(dapsox)(H2O)2]+ cation (pK a1 = 5.94 and pK a2 = 9.04), the induced ionization of the amide bond and the formation constants of the complexes formed in solution were calculated using the nonlinear least-squares program MINIQUAD-75. The stoichiometry and stability constants for the complexes formed are reported. The results show the formation of 1:1 and 1:2 complexes with DNA constituents supporting the hepta-coordination mode of Fe(III). The concentration distributions of the various complex species were evaluated as a function of pH. The thermodynamic parameters ΔH° and ΔS° calculated from the temperature dependence of the equilibrium constants were investigated for interaction of [Fe(dapsox)(H2O)2] with uridine.  相似文献   

8.
The title compound [Pr(C7H3NO5)(C7H4NO5)(H2O)2] n · 1.25nH2O (1) or [Pr(HChel)(H2Chel)(H2O)2] n · 1.25nH2O, where H3Chel is 4-hydroxypyridine-2,6-dicarboxylic (chelidamic) acid, was synthesized by reaction of chelidamic acid, PrCl3 · 6H2O and H2O under hydrothermal conditions, and characterized by X-ray single-crystal diffraction. The crystal structure of 1 reveals that Pr is nine-coordinate with distorted tricapped trigonal prismatic coordination. Coordination polyhedra are interlinked into a 1-D chain, further linked by hydrogen bonds into a 3-D network. Fluorescence spectra exhibit strong green luminescence with maximum emission at 530 nm when excited with λ ex = 475 nm, originating from π–π* of the ligand.  相似文献   

9.
Three new Co(II) coordination polymers, [Co(L1)(bpdc)] n (1), [Co(L2)(ndc)(H2O)·2H2O] n (2) and [Co(L3)(ndc)(H2O)·H2O] n (3) (L1 = 1,2-bis(5,6-dimethylbenzimidazole)ethane, L2 = 1,3-bis(5,6-dimethylbenzimidazole)propane, L3 = 1,4-bis(5,6-dimethylbenzimidazole)butane, H2bpdc = 4,4′-biphenyldicarboxylic acid, H2ndc = 2,6-naphthalenedicarboxylic acid) have been synthesized under hydrothermal conditions and structurally characterized by X-ray crystallography. All three complexes feature (4,4) networks that extend into 3D supramolecular frameworks via hydrogen bonding interactions. The luminescence properties and catalytic activities of these complexes with respect to the degradation of methyl orange in a Fenton-like process have been investigated.  相似文献   

10.
A 3D supramolecule (H3O)2[Cu(2,6-pdc)2]·H2O (pdc = pyridinedicarboxylate) has been solvothermally synthesized and characterized by X-ray powder diffraction and FT-IR spectrum. The thermal decomposition characteristics of the complex were investigated by thermogravimetric analysis, which revealed a three-step mass loss process. The low-temperature molar heat capacities of crystalline (H3O)2[Cu(2,6-pdc)2]·H2O were measured by temperature-modulated differential scanning calorimetry for the first time. A phenomenon of glass transition was observed. The thermodynamic parameters such as entropy and enthalpy relative to 298.15 K were calculated based on the above molar heat capacity data.  相似文献   

11.
[Cu(pydc)(eim)3]?H2O (1), [Cu(pydc)(4hp)(H2O)] (2), and [Ni(pydc)(3hp)(H2O)2][Cu(pydc)(3hp)(H2O)2]?3H2O (3) (H2pydc = 2,6-pyridinedicarboxylic acid or dipicolinic acid, eim = 2-ethylimidazole, 4hp = 4-hydroxypyridine, 3hp = 3-hydroxypyridine) were synthesized and characterized by elemental analysis, spectroscopic measurements (UV–vis and IR spectra), and single-crystal X-ray diffraction. Crystal analysis revealed that the complexes extended to 3-D supramolecular networks through intermolecular H-bonding and molecular interactions between the ligand moieties and water molecules. The thermal stabilities of complexes are investigated by thermogravimetry, differential thermogravimetry, and differential thermal analysis techniques. The effects of complexes on the proliferation of HT-1080 fibrosarcoma cells were investigated using the quick cell proliferation assay. The cell viability changes were found to depend on the concentrations and type of complex.  相似文献   

12.
Kinetics of aqua ligand substitution from [(H2O)(tap)2RuORu(tap)2(H2O)]2+ {tap = 2-(m-tolylazo)pyridine}, by three vicinal dioximes, namely dimethylglyoxime (L1H), 1,2-cyclohexanedione dioxime (L2H) and α-furil dioxime (L3H), have been studied spectrophotometrically in the 35–50 °C temperature range. The reaction was monitored at 560 nm where the absorbance between the reactant and product is at a maximum. At pH 7.4, the reaction has been found to proceed via two distinct consecutive steps, i.e., it shows a non-linear dependence on the concentration of ligands: the first process is [ligand] dependent but the second step is [ligand] independent. The rate constants for the processes are: k 1 ~ 10?3 s?1 and k 2 ~ 10?4 s?1. The activation parameters, calculated from Eyring plots, suggest an associative mechanism for the interaction process. From the temperature dependence of the outer sphere association equilibrium constants, the thermodynamic parameters were also calculated, which give negative ΔG° values at all temperatures studied, supporting the spontaneous formation of an outer sphere association complex. The product of the reaction has been characterized with the help of IR and ESI-mass spectroscopic analysis.  相似文献   

13.
Through ligand modification, we have replaced the central benzene ring of H2TDBA ([1,1′:3′,1″-terphenyl]-4,4″-dicarboxylic acid) with the pyridine structurally related ligand H2PDDA (4,4′-(pyridine-2,6-diyl)dibenzoic acid), which makes the central pyridine ring of H2PDDA more coplanar with two benzene rings on both sides of the ligand. The modification results in a dramatically different linkage configuration, thereby allowing structural changes to the metal-organic frameworks (MOFs). Two 2-D MOFs, [Cu(TDBA)(DMA)2]·H2O (BUT-221, DMA = N,N-dimethylacetamide), and [Cu3(PDDA)3(DMA)2(H2O)]·5H2O (BUT-223) have been synthesized through reactions of two ditopic carboxylate ligands with Cu(NO3)2·3H2O under solvothermal conditions, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Topological analysis shows that BUT-221 is a twofold parallel interpenetrating 44 2-D network with a skl topology, while BUT-223 is a 2-D network with a kgm topology.  相似文献   

14.
The aim of this study was to explore the influence of the position and angles of carboxyl groups of polycarboxylates on constructing coordination polymers. Three Co(II) metal–organic coordination polymers based on a tri-pyridyl-bis-amide ligand, namely [Co(L)(1,2-BDC)(H2O)2]·2H2O (1), [Co(L)(1,4-BDC)(H2O)2]·2H2O (2) and [Co(L)2(BTEC)0.5]·H2O (3) (L = N,N′-bis(pyridine-3-yl)pyridine-2,6-dicarboxamide, 1,2-H2BDC = 1,2-benzenedicarboxylic acid, 1,4-H2BDC = 1,4-benzenedicarboxylic acid, H4BTEC = 1,2,4,5-benzenetetracarboxylic acid), have been obtained by tuning the auxiliary polycarboxylate ligands. Structural analyses reveal that complexes 13 display diverse structures. Complex 1 displays a meso-helical chain linked by L ligands, which is further extended into a three-dimensional supramolecular framework through hydrogen-bonding interactions. The 1,2-BDC with a chelating coordination mode only acts as the hydrogen bond acceptor. In complex 2, the 1,4-BDC anions connect adjacent Co(II) atoms to form a linear chain, which is connected by hydrogen-bonding interactions to construct a 3D supramolecular network. Complex 3 exhibits a chain, which is composed of left-/right-handed Co-L helical chains and Co-BTEC linear chain. The 1D chains are ultimately extended into a two-dimensional supramolecular network by hydrogen-bonding interactions. Moreover, the thermal stability and the fluorescent properties of the title complexes and the electrochemical behaviors of a bulk-modified carbon paste electrode with complex 2 have been investigated at room temperature.  相似文献   

15.
The sodium complex [{Ph2P(O)NH(2,6‐Me2C6H3)}Na{Ph2P(O)N(2,6‐Me2C6H3)}]2 ( 2 ) with the ligand N‐(2,6‐dimethylphenyl)diphenylphosphinic amide was synthesized involving the reaction of the neutral ligand [Ph2P(O)NH(2,6‐Me2C6H3)] ( 1 ) and sodium bis(trimethylsilyl)amide in toluene at 60 °C. The calcium complex [{Ph2P(O)NH(2,6‐Me2C6H3)CaI(THF)3}I] ( 3 ) was obtained by the reaction between the neutral ligand 1 and anhydrous calcium diiodide in THF at ambient temperature. The solid‐state structures of the complexes were established by single‐crystal X‐ray diffraction analysis. In the solid‐state structure of 2 , the sodium ion is coordinated through the chelation of oxygen atom attached to the phosphorus atom. Two different P–N and P–O bond lengths are observed, which indicates that one ligand moiety is anionic, whereas the second one is neutral. In the solid‐state structure of 3 , the calcium atom adopts distorted octahedral arrangement through the ligation of two phosphinic amide ligands, three THF molecules, and one iodide ion.  相似文献   

16.
Hydrothermal reaction of CuSO4·7H2O and NaN3 with 2-cyanothiophene in aqueous ethanol yielded a novel tetranuclear copper(I) polymer, {[Cu4(tptz)4]·0.5(C2H6O)}n (1) (Htptz = 5-(thiophen-2-yl)-1H-tetrazole). The tptz ligand in the complex was generated through an in situ [2 + 3] cycloaddition reaction involving the cyano groups of the precursor 2-cyanothiophene. In a rare example, three different geometries of Cu(I) cations, namely the linear, triangle, and tetrahedron geometries of Cu(I) centers, are created and linked by Htptz ligands into a 1-D ladder structure. Additionally, 1 exhibits strong blue fluorescence (with λ = 467 nm) at room temperature in the solid state.  相似文献   

17.
The Pd(DAP)Cl2 complex, where DAP is 2,6-diaminopyridine, was synthesized and characterized. The stoichiometries and stability constants of the complexes formed between various biologically relevant ligands (amino acids, amides, DNA constituents, and dicarboxylic acids) and [Pd(DAP)(H2O)2]2+ were investigated at 25 °C and at constant 0.1 mol·dm?3 ionic strength. The concentration distribution diagrams of the various species formed were evaluated. A further investigation of the binding properties of the diaqua complex [Pd(DAP)(H2O)2]2+ with calf thymus DNA (CT-DNA) was investigated by UV–Vis spectroscopy. The intrinsic binding constants (K b) calculated from UV–Vis absorption studies is 1.04 × 103 mol·dm?3. The calculated (K b) value was found to be of lower magnitude than that of the classical intercalator EB (ethidium bromide) (K b = 1.23 (±0.07) × 105 mol·dm?3), suggesting an electrostatic and/or groove binding mode for the interaction with CT-DNA.  相似文献   

18.
Assembly of orotic acid (H3Or, 1,2,3,6-tetrahydro-2,6-dioxo-4-pyrimidinecarboxylic) and Cd(NO3)·6H2O yielded a coordination polymer, [(Cd(Hor)·2.5H2O)2]n (1), which has been characterized by X-ray single-crystal diffraction, TGA, and ?uorescence spectra. Single-crystal X-ray structural analyses reveal that 1 is a hydrogen-bonded binuclear Cd-orotate coordination polymer in which both Cd2+ ions have different coordination environments with identical distorted octahedral geometry. Crystal data for 1: monoclinic, space group P21/n, a = 7.0209(10) Å, b = 13.974(2) Å, c = 17.541(3) Å, β = 98.842(2)°, V = 1700.5(4) Å, Z = 4, R1 = 0.0269, wR2 = 0.0612, θmax = 25.960. The emission spectrum of the Cd-complex recorded with 265 nm excitation wavelength reveals the complex has strong blue luminescence with the peak maximum 420 nm (2.95 eV) as a result of the nπ* and ππ* transitions on the H3Or ligand.  相似文献   

19.
Two Cd(II) coordination polymers constructed from tris(p-carboxylphenyl)phosphine oxide (H3TPO), [Cd(HTPO)(1,4-bix)·3H2O]n (1) and [Cd2(HTPO)(HBPO)(H2O)2]n (2) (1,4-bix = 1,4-bis(imidazol-1-ylmethyl)benzene, H3BPO = bis(4-carboxylphenyl)phosphinic acid), were synthesized and identified by IR, elemental analysis, and single-crystal X-ray diffraction analysis. The 1,4-bix ligand leads to 1 as a ladder-like 1D chain structure. In 2, adjacent Cd2 units are bridged by HBPO2– and HTPO2– ligands to form a 3D structure. The H3BPO ligand is formed from the in situ reaction of H3TPO. It is the first example from hydrated Cd(II) salt promoting partial hydrolysis of a phosphine oxide ligand. The thermal behavior and solid-state photoluminescence properties correlated with the corresponding structural features were investigated.  相似文献   

20.
A novel 5-aminotetrazole mixed ligands complex of formula [Cu(PTS)2(ATZ)2(H2O)2] (C16H24CuN10O8S2, PTS = p-toluenesulfonate, ATZ = 5-aminotetrazole) has been obtained by the reaction of 5-aminotetrazole with copper acetate and p-toluenesulfonic acid on heating in water. It was characterized by elemental analysis, FT-IR spectroscopy, and X-ray single crystal diffraction. The compound crystallizes in monoclinic system, space group P21/c, Z = 2, a = 14.079(4) Å, b = 6.088(3) Å, c = 14.632(4) Å, β = 105.268(4)°, V = 1209.8(5) Å3. The central copper(II) cation is coordinated by two N atoms and four O atoms from two ATZ ligands, two water molecules and two p-toluenesulfonate ions to form a six-coordinated and distorted octahedral structure. Neutral ATZ is coordinated in the monodentate mode by the N(4) atom. The sulfonate group of the PTS ligand remains weak-coordinated modes and forms a number of hydrogen bonds with water molecule ligands and ATZ ligands. A supramolecular framework is connected by electrostatic interaction, weak coordinated bonding, hydrogen-bonding, and π–π interaction. The thermal decomposition mechanism of the title compound was predicted based on DSC, TG-DTG, and FT-IR analyses. Thermolysis of ATZ and its several derivatives is compared.  相似文献   

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