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1.
A. Zalga Z. Moravec J. Pinkas A. Kareiva 《Journal of Thermal Analysis and Calorimetry》2011,105(1):3-11
The preparation and characterization of the M′–M′′–O nitrate–tartrate (M′ = Ca, Ba, Gd and M′ = W, Mo) precursor gels synthesized
by simple, inexpensive, and environmentally benign aqueous sol–gel method is reported. The obtained gels were studied by thermal
(TG/DSC) analysis. TG/DSC measurements revealed the possible decomposition pathway of synthesized M′–M′′–O nitrate–tartrate
gels. For the synthesis of different metal tungstates and molybdates, the precursor gels were calcined at different temperatures
(650, 800, and 900 °C). According to the X-ray diffraction (XRD) analysis data, the crystalline compounds CaMo1-x
W
x
O4 doped with Ce3+ ions, BaMo1-x
W
x
O4 doped with Eu3+ ions and Gd2Mo3O12 were obtained from nitrate–tartrate gels annealed at 650–900 °C temperatures. The XRD data confirmed that the fully crystalline
single-phase powellite, scheelite, or Gd2(MoO4)3 structures were formed already at 650 °C. Therefore, the suggested sol–gel method based on the complexation of metal ions
with tartaric acid is suitable for the preparation of mixed tungstates–molybdates at relatively low temperature in comparison
with solid-state synthesis. 相似文献
2.
Lucica Viorica Ababei Angela Kriza Cristian Andronescu Adina Magdalena Musuc 《Journal of Thermal Analysis and Calorimetry》2012,107(2):573-584
Ten new mononuclear complexes having general formulae [ML2](ClO4)2, M = Cu(II), Co(II), Ni(II), Mn(II) and Zn(II), [ML2](SO4), M = Co(II), Ni(II) and [ML2(H2O)2](SO4), M = Cu(II), Mn(II) and Zn(II), L = 2-acetyl-pyridyl-isonicotinoylhydrazone have been synthesized and characterized based
on elemental analyses, IR spectroscopy, UV–Vis–NIR, EPR, as well as thermal analysis and determination of molar conductivity
and magnetic moments. The structures of [CoL2](ClO4)2 are accomplished by single crystal X-ray diffraction. The coordination sphere is formed by two N, N, O tridentates 2-acetyl-pyridyl-isonicotinoylhydrazone
ligands, or by two N, O bidentate 2-acetyl-pyridyl-isonicotinoylhydrazone and two water molecules. Biological activity studies
reveal a moderate activity of complexes against gram-negative and gram-positive bacteria. 相似文献
3.
Solvothermal synthesis and structures of three novel heterometallic microporous coordination polymers assembled from 2-hydroxy-nicotinic acid 总被引:1,自引:0,他引:1
Hua Hong Zou Shu Hua Zhang Yu Xiao Chao Feng Yin Guang Wang 《Structural chemistry》2011,22(1):135-140
Abstract
Three novel heterometallic microporous coordination polymers {M(Hnico)3M′} n (1, M = Co, M′ = K; 2, M = Ni, M′ = K; 3, M = Co, M′ = Na, Hnico is the anion of 2-hydroxy-nicotinic acid, where the proton is transferred from the phenolate hydroxy group to the nitrogen atom of imine pyridine ring) were synthesized by hydrothermal reaction between M(Ac)2·4H2O, M′OH and a multifunctional organic aromatic H2nico ligand and characterized by IR spectrum, elemental analysis, raman spectrum and the single crystal X-ray diffractions. In complexes 1–3, the M2+ ions linked three different Hnico ligand formed [M(Hnico)3]− subunit which further interlinked the six-coordination M′+ cation constructed 3D network. The network topology of 1–3 can be simplified a rare 3D (4,4)-connected (41263) net. 相似文献4.
Co(II), Ni(II), Cu(II) and Zn(II) complexes of aminothiazole‐derived Schiff base ligands: Synthesis,characterization, antibacterial and cytotoxicity evaluation,bovine serum albumin binding and density functional theory studies 下载免费PDF全文
Transition metal complexes of type M(L)2(H2O)x were synthesized, where L is deprotonated Schiff base 2,4‐dihalo‐6‐(substituted thiazol‐2‐ylimino)methylphenol derived from the condensation of aminothiazole or its derivatives with 2‐hydroxy‐3‐halobenzaldehyde and M = Co2+, Ni2+, Cu2+ and Zn2+ (x = 0 for Cu2+ and Zn2+; x = 2 for Co2+ and Ni2+). The synthesized Schiff bases and their metal complexes were thoroughly characterized using infrared, 1H NMR, electronic and electron paramagnetic resonance spectroscopies, elemental analysis, molar conductance and magnetic susceptibility measurements, thermogravimetric analysis and scanning electron microscopy. The results reveal that the bidentate ligands form complexes having octahedral geometry around Co2+ and Ni2+ metal ions while the geometry around Cu2+ and Zn2+ metal ions is four‐coordinated. The geometries of newly synthesized Schiff bases and their metal complexes were fully optimized in Gaussian 09 using 6–31 + g(d,p) basis set. Fluorescence quenching data reveal that Zn(II) and Cu(II) complexes bind more strongly to bovine serum albumin in comparison to Co(II) and Ni(II) complexes. The ligands and their complexes were evaluated for in vitro antibacterial activity against Escherichia coli ATCC 25922 (Gram negative) and Staphylococcus aureus ATCC 29213 (Gram positive) and cytotoxicity against lever hepatocellular cell line HepG2. 相似文献
5.
The reaction of [M(L)]Cl2 · 2H2O (M = Ni2+ and Cu2+, L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane) with 1,1-cyclobutanedicarboxylic acid (H2-cbdc) generates 1D and 2D hydrogen-bonded infinite chains [Ni(L)(H-cbdc−)2] (1) and [Cu(L)(H-cbdc−)2] (2). (H-cbdc− = cyclobutane-1-carboxylic acid-1-carboxylate). These complexes have been characterized by X-ray crystallography, spectroscopy,
and cyclic voltammetry. The crystal structure of 1 shows a distorted octahedral coordination geometry around the nickel(II) ion, with four secondary amines and two oxygen atoms
of the H-cbdc− ligand at the trans position. In 2, the coordination environment around the central copper(II) ion shows a Jahn–Teller distorted octahedron with four Cu–N bonds
and two long Cu–O distances. The cyclic voltammogram of the complexes undergoes two one-electron waves corresponding to MII/MIII and MII/MI processes. The electronic spectra and electrochemical behavior of the complexes are significantly affected by the nature
of the axial H-cbdc− ligand. 相似文献
6.
Two new complexes with formula VOL2·nH2O ((1) L: 4′,5,7-trihydroxyflavone-7-rhamnoglucoside (naringin), n = 8; (2) L: 3′,4′,7-tris[O-(2-hydroxyethyl)]rutin (troxerutin), n = 0) were synthesised and characterised. The IR and UV–Vis spectral data indicate that these flavones act as bidentate chelating
ligands and generate VO(II) complexes with a square-pyramidal stereochemistry. The thermal analysis (TG, DTA) elucidated the
composition and also the number and nature of the water molecules. The thermal behavior indicates also a strong interaction
between oxovanadium (IV) and these oxygen donor ligands. 相似文献
7.
Two novel amino acids imine ligands (H2L1 and H2L2) have been synthesized using green condensation reaction from 2‐[3‐Amino‐5‐(2‐hydroxy‐phenyl)‐5‐methyl‐1,5‐dihydro‐[1, 2, 4]triazol‐4‐yl]‐3‐(1H‐indol‐3‐yl)‐propionic acid with benzaldehyde/p‐flouro benzaldehyde (1:1 molar ratio) in the presence of lemon juice as a natural acidic catalyst in aqueous medium. Their transition metal complexes have been prepared in a molar ratio (1:1). Characterization of the ligands and complexes using elemental analysis, spectroscopic studies, 1HNMR, 13CNMR, and thermal analysis has been reported. E*, ΔH*, ΔS* and ΔG* thermodynamic parameters, were calculated to throw more light on the nature of changes accompanying the thermal decomposition process of these complexes. The molar conductance measurement of metal complexes showed nonelectrolyte behavior. The metal complexes of the two ligands have tetrahedral geometry with a general molecular structure [M(H2L)Xn], where [(M = Mn (II), Co (II), Cu (II) and Zn (II), X = Cl, n = 2]; M = VO (II), X = SO4, n = 1] for H2L1. [M = Co (II), Cu (II), Zn (II)] for H2L2. Antibacterial activity of the complexes against (Bacillis subtilis, Micrococcus luteus, Escherichia coli), also antifungal activity against (Aspergillus niger, Candida Glabarta, Saccharomyces cerevisiae) have been screened. The results showed that all complexes have antimicrobial activity higher than free ligands. Molecular docking studies results showed that, all the synthesized compounds having minimum binding energy and have good affinity toward the active pocket, thus, they may be considered as good inhibitor of targeting PDB code: 1SC7 (Human DNA Topo‐isomerase I). 相似文献
8.
The catalytic epoxidation of styrene using urea-hydrogen peroxide and heterotrinuclear Cu(II) complexes with general formula
(ML
n
)2Cu(acac)2, where n = 1–3 and M = VO2+ or Mn2+ is reported. Schiff base complexes ML
n
involving a 3,4-diaminopyridine bridge with free coordination site were used as the ligand, where (Ln)2− is [(5-x-Sal)2Py]2 and x = H, Br or NO2. The complexes were characterized by physico-chemical and spectroscopic methods. The electrochemical properties of M were
modified upon trinuclear complex formation. The trinuclear complexes show high catalytic activity, with up to 86% conversion
and 93% selectivity, while no catalytic properties were observed for the monomeric complexes. The catalyst could be reused
with some loss of activity. 相似文献
9.
M. H. Soliman Gehad G. Mohamed Eman A. Mohamed 《Journal of Thermal Analysis and Calorimetry》2010,99(2):639-647
Metal complexes of fenoterol (FEN) drug are prepared and characterized based on elemental analyses, IR, 1H NMR, magnetic moment, molar conductance, and thermal analyses (TG and DTA) techniques. From the elemental analyses data,
the complexes are formed in 1:2 [Metal]:[FEN] ratio and they are proposed to have the general formula [Cu(FEN)2]·2H2O; [M(FEN)2(H2O)2]·yH2O (where M = Mn(II) (y = 2), Co(II) (y = 4), Ni(II) (y = 4), and Zn(II) (y = 0) and [Cr(FEN)2(H2O)2]Cl·H2O. The molar conductance data reveal that all the metal chelates are non-electrolytes except Cr(III) complex, having 1:1 electrolyte.
IR spectra show that FEN is coordinated to the metal ions in a uninegative bidentate manner with ON donor sites of the aliphatic
–OH and secondary amine –NH. From the magnetic moment measurements, it is found that the geometrical structures of these complexes
are octahedral (Cr(III), Mn(II), Co(II), Ni(II), and Zn(II)) and square planar (Cu(II)). The thermal behavior of these chelates
is studied using thermogravimetric and differential thermal analyses (TG and DTA) techniques. The results obtained show that
the hydrated complexes lose water molecules of hydration followed immediately by decomposition of the coordinated water and
ligand molecules in the successive unseparate steps. The FEN drug, in comparison to its metal complexes is also screened for
their antibacterial activity against bacterial species (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella typhi), Yeasts (Candida albicans and Saccharomyces cervisiae), and Fungi (Aspergillus niger and Aspergillus flavus). The activity data show that the metal complexes have antibacterial activity like that of the parent FEN drug against one
or more species. 相似文献
10.
Derivative of 8-hydroxyquinoline i.e. Clioquinol is well known for its antibiotic properties, drug design and coordinating
ability towards metal ion such as Copper(II). The structure of mixed ligand complexes has been investigated using spectral,
elemental and thermal analysis. In vitro anti microbial activity against four bacterial species were performed i.e. Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Bacillus substilis and found that synthesized complexes (15–37 mm) were found to be significant potent compared to standard drugs (clioquinol
i.e. 10–26 mm), parental ligands and metal salts employed for complexation. The kinetic parameters such as order of reaction
(n = 0.96–1.49), and the energy of activation (E
a = 3.065–142.9 kJ mol−1), have been calculated using Freeman–Carroll method. The range found for the pre-exponential factor (A), the activation entropy (S* = −91.03 to−102.6 JK−1 mol−1), the activation enthalpy (H* = 0.380–135.15 kJ mol−1), and the free energy (G* = 33.52–222.4 kJ mol−1) of activation reveals that the complexes are more stable. Order of stability of complexes were found to be [Cu(A4)(CQ)OH] · 4H2O > [Cu(A3)(CQ)OH] · 5H2O > [Cu(A1)(CQ)OH] · H2O > [Cu(A2)(CQ)OH] · 3H2O 相似文献
11.
A. López-Hernández K. Venkatesan H. W. Schmalle Heinz Berke 《Monatshefte für Chemie / Chemical Monthly》2009,36(10):845-857
Abstract
Stable paramagnetic Cr(II) and Cr(III) bis(alkynyl) complexes of the type [trans(RC≡C)2Cr(dmpe)2] n+ (R = Ph, SiMe3, SiEt3, C≡C–SiMe3 n = 0, 1) were prepared and characterised by NMR, cyclic voltammetry, EPR, magnetic measurements, and X-ray single-crystal diffraction studies. 相似文献12.
M. M. Omar 《Journal of Thermal Analysis and Calorimetry》2002,68(3):1003-1015
Formation constants (logK
MAL
MA) of the mixed complexes of the type M–A–L (where M=Mn(II), Co(II), Ni(II), Cu(II), Ce(III), Th(IV), and UO2(II); A=oxine and L=sulphamerazine or sulphadiazine) have been determined pH-metrically in 60% (v/v) ethanol–water mixture at 25°C and constant ionic strength (μ=0.1 M NaCl). The mode of chelation was ascertained by conductivity
measurements. The stability sequence with respect to metal ions have been found to be Cu(II)>Ni(II)>Co(II)>Mn(II) and Th(IV)>UO2(II)>Ce(III). CuAL ternary solid complexes have been prepared and characterized on the basis of elemental analysis and IR-spectroscopy.
The thermal degradations of the prepared complexes are discussed in an attempt to assign the intermediate compounds formed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
Two coordination polymers, namely [M(cpna)(phen)(H2O)]
n
(M = Ni, 1; Cd, 2, H2cpna = 5-(2′-carboxylphenyl) nicotic acid, phen = 1,10-phenanthroline), have been hydrothermally synthesized and characterized
by single-crystal X-ray diffraction, magnetic and luminescence measurements. Single-crystal X-ray diffraction studies show
that the two complexes are isostructural polymers. They have 1D step-like chain structures, which are further extended into
3D metal–organic supramolecular frameworks by π–π stacking interactions. Magnetic studies for complex 1 show antiferromagnetic coupling between the adjacent Ni(II) centers, with g = 2.10 and J = −4.30 cm−1. Complex 2 displays strong green fluorescent emission at room temperature. 相似文献
14.
S. Vairam T. Premkumar S. Govindarajan 《Journal of Thermal Analysis and Calorimetry》2010,101(3):979-985
Hydrazine forms two different types of complexes with divalent metal ions and pyromellitic acid (H4pml) in aqueous medium: (i) hydrazinium complexes of formulae, (N2H5)2M(pml)·xH2O, where x = 3 for M=Ni and x = 4 for M=Co or Zn, and (N2H5)2Mn(H2pml)2, at pH 4.5, (ii) neutral hydrazine complexes with formulae, M2(pml)(N2H4)
n
·xH2O where M=Co or Ni when n = 4 and x = 5 or 4 and M=Zn or Cd when n = 2, and x = 4 or 3 at pH 7, and M(H2pml)(N2H4)·xH2O where x = 4; M=Cu and x = 0; M=Hg, at pH 3, 7.5, respectively. All the complexes are insoluble in water, alcohol and ether. The N–N stretching frequency
(990–1,007 cm−1 for coordinated hydrazinium ion and 956–985 cm−1 for bridged neutral hydrazine) indicates the nature of hydrazine present in the complexes. Simultaneously TG-DTA analysis
indicates that hydrazinium complexes undergo dehydration and dehydrazination in a single step endothermally in the range of
289–300 °C whereas neutral hydrazine complexes undergo endothermic dehydration (~100 °C) followed by exothermic dehydrazination
in the temperature range, 253–332 °C. The anhydrous metal carboxylates further decompose exothermally to leave the respective
metal oxides or metal carbonates except zinc, which gives its oxalate as the end product. X-ray powder patterns indicate that
even the complexes with the same formulation possess no isomorphism. 相似文献
15.
C. Menapace I. Lonardelli A. Molinari 《Journal of Thermal Analysis and Calorimetry》2010,101(3):815-821
New complexes of type [Cu(HTBG)2]Cl2 (1), [Cu(TBG)2]·3H2O (2) and [CuL]·nH2O (3) L:L1, n = 2 and (4) L:L2, n = 1 (HTBG: 2-tolylbiguanide, L1 and L2: ligands resulted from 2-tolylbiguanide, ammonia/hydrazine and formaldehyde one pot condensation) were synthesised and characterised.
The features of complexes have been assigned from microanalytical, IR and UV–Vis data. Redox behaviour was established by
cyclic voltammetry. The in vitro qualitative and quantitative antimicrobial activity assays showed that the complexes exhibited
variable antimicrobial activity against Gram-negative and Gram-positive strains isolated from the hospital environment. The
thermal analyses have evidenced the thermal intervals of stability and also the thermodynamic effects that accompany them.
After water elimination, complexes have a similar thermal behaviour. Processes as water elimination, melting, chloride anion
removal as well as oxidative degradation of the organic ligands were observed. The final product of decomposition was copper
(II) oxide. 相似文献
16.
《应用有机金属化学》2017,31(10)
New mixed ligand complexes of transition metals were synthesized from a Schiff base (L1) obtained by the condensation reaction of oxamide and furfural as primary ligand and 2,2′‐bipyridine (L2) as secondary ligand. The ligands and their metal complexes were studied using various spectroscopic methods. Also thermal analyses were conducted. The mixed ligand complexes were found to have formulae [M(L1)(L2)]Clm ⋅n H2O (M = Cr(III) and Fe(III): m = 3, n = 0; M = Cu(II) and Cd(II): m = 2, n = 1; M = Mn(II), Co(II), Ni(II) and Zn(II): m = 2, n = 0). The resultant data revealed that the metal complexes have octahedral structure. Also, the mixed ligand complexes are electrolytic. The biological and anticancer activities of the new compounds were tested against breast cancer (MCF‐7) and colon cancer (HCT‐116) cell lines. The results showed high activity for the synthesized compounds. 相似文献
17.
Adrian Topolski Monika Lipiska Przemysaw Kita Joanna Winiewska 《Transition Metal Chemistry》2008,33(7):843-847
The formation of CuII–Br–FeIII-type heterobimetallic complexes was observed spectrophotometrically, given the non-additivity of the spectra from the copper(II)
and iron(III) complexes. The kinetics of the oxidation of promazine radical (ptz+•) to promazine 5-oxide, by iron(III) bromides, copper(II) bromides, and a mixture of these complexes in acidic aqueous solutions,
have been studied using UV–Vis spectroscopy at I = 1.0 M (H+, Cu2+, Fe3+, Br−) and T = 318 K. Copper(II) inhibits the oxidation of the promazine radical to promazine sulfoxide using iron(III) complexes. A rate
retardation effect, characterized by the dependence of the pseudo second-order rate constant (k
II) on the copper(II) concentration k
II = a/(1 + b[CuII]), can be rationalized as a result of CuII–Br–FeIII-type heterobimetallic complex formation. 相似文献
18.
Shashi B. Kalia Priyanka Sankhyan R. Puri J. Christopher 《Journal of Thermal Analysis and Calorimetry》2012,107(2):597-605
Non-isothermal techniques, i.e. thermogravimetry (TG) and differential scanning calorimetry (DSC), have been applied to investigate
the thermal behaviour of carbaryl (1-naphthyl-N-methylcarbamate = 1-Naph-N-Mecbm) and its complexes, M(1-Naph-N-Mecbm)4X2, where M = Cu, X = Cl, NO3 and CH3COO and M = Zn, X = Cl. Carbaryl and Zn(1-Naph-N-Mecbm)4Cl2 complex exhibit two-stage thermal decomposition while the copper(II) complexes exhibit three and four-stage decomposition
in their TG curves. The nature of the metal ion has been found to play highly influential role on the nature of thermal decomposition
products as well as energy of activation ‘E*’. The presence of different anions does not seem to alter the thermal decomposition patterns. The complexes display weak
to medium intensity exothermic and endothermic DSC curves, while the free ligand exhibits two endothermic peaks. The kinetic
and thermodynamic parameters namely, the energy of activation ‘E*’, the frequency factor ‘A’ and the entropy of activation ‘S*’ etc. have been rationalized in relation to the bonding aspect of the carbaryl ligand. The nature and chemical composition
of the residues of the decomposition steps have been studied by elemental analysis and FTIR data. 相似文献
19.
Kateryna E. Gubina Oleg A. Maslov Elizaveta A. Trush Victor A. Trush Vladimir A. Ovchynnikov Svetlana V. Shishkina Vladimir M. Amirkhanov 《Polyhedron》2009,28(13):2661-2666
This paper presents examples of mixed-ligand Co(II), Cu(II), Ni(II) and Mn(II) complexes, with a distorted octahedral coordination geometry, with 2,2′-dipyridyl or 1,10-phenanthroline and phosphortriamide ligands. The complexes of the general type ML2·Lig (where M = Co(II), Cu(II), Ni(II), Mn(II); L− = {Cl3C(O)NP(O)R2}− (R = NHBz, NHCH2CHCH2, NEt2); Lig = 2,2′-dipyridyl or 1,10-phenanthroline) were synthesised and characterised by means of X-ray diffraction, IR and UV–Vis spectroscopy. The phosphortriamide ligands are coordinated via oxygen atoms of phosphoryl and carbonyl groups involved in six-membered metal cycles. The additional ligands 2,2′-dipyridyl or 1,10-phenanthroline are coordinated to the central atom, forming five-membered cycles. 相似文献
20.
The complexes of 4-chloro-2-methoxybenzoic acid anion with Mn2+,
Co2+, Ni2+, Cu2+
and Zn2+ were obtained as polycrystalline solids
with general formula M(C8H6ClO3)2·nH2O and colours typical for M(II) ions (Mn – slightly pink, Co –
pink, Ni – slightly green, Cu – turquoise and Zn – white).
The results of elemental, thermal and spectral analyses suggest that compounds
of Mn(II), Cu(II) and Zn(II) are tetrahydrates whereas those of Co(II) and
Ni(II) are pentahydrates. The carboxylate groups in these complexes are monodentate.
The hydrates of 4-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II), Cu(II)
and Zn(II) heated in air to 1273 K are dehydrated in one step in the range
of 323–411 K and form anhydrous salts which next in the range of 433–1212
K are decomposed to the following oxides: Mn3O4,
CoO, NiO and ZnO. The final products of decomposition of Cu(II) complex are
CuO and Cu. The solubility value in water at 293 K for all complexes is in
the order of 10–3 mol dm–3.
The plots of χM
vs.
temperature of 4-chloro-2-methoxybenzoates of Mn(II), Co(II), Ni(II) and Cu(II)
follow the Curie–Weiss law. The magnetic moment values of Mn2+,
Co2+, Ni2+ and Cu2+
ions in these complexes were determined in the range of 76−303 K and
they change from: 5.88–6.04 μB for Mn(C8H6ClO3)2·4H2O, 3.96–4.75
μB for Co(C8H6ClO3)2·5H2O, 2.32–3.02 μB for Ni(C8H6ClO3)2·5H2O and 1.77–1.94
μB for Cu(C8H6ClO3)2·4H2O. 相似文献