共查询到20条相似文献,搜索用时 15 毫秒
1.
Morteza Bahram Khalil Farhadi Abbas Afkhami Donya Shokatynia Farzin Arjmand 《Central European Journal of Chemistry》2009,7(3):375-381
A partial least squares (PLS-1) calibration model based on kinetic—spectrophotometric measurement, for the simultaneous determination
of Cu(II), Ni(II) and Co(II) ions is described. The method was based on the difference in the rate of the reaction between
Co(II), Ni(II) and Cu(II) ions with 1-(2-pyridylazo)2-naphthol in a pH 5.8 buffer solution and in micellar media at 25°C.
The absorption kinetic profiles of the solutions were monitored by measuring the absorbance at 570 nm at 2 s intervals during
the time range of 0–10 min after initiation of the reaction. The experimental calibration matrix for the partial least squares
(PLS-1) model was designed with 30 samples. The cross-validation method was used for selecting the number of factors. The
results showed that simultaneous determination could be performed in the range 0.1-2 μg mL−1 for each cation. The proposed method was successfully applied to the simultaneous determination of Cu(II), Ni(II) and Co(II)
ions in water and in synthetic alloy samples.
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2.
Valentina T. Getova Ivayla N. Pantcheva Darvin S. Ivanov Dimitar R. Mehandjiev Vassil Skumryev Panayot R. Bontchev 《Central European Journal of Chemistry》2007,5(1):118-131
The complexation of the non-selective β-blocker nadolol, HL, 1 with copper(II) leads to formation of mono-and dinuclear complexes depending mainly on the metal-to-ligand molar ratio. The
mononuclear violet complex CuL2·2Solv, 2, was obtained in a soluble form at metal-to-ligand molar ratio Cu(II): HL ≤ 1: 10 in methanolic or slightly alkaline aqueous
solutions. The dinuclear green complex Cu2L2Cl2·H2O, 3 was synthesized at Cu(II): HL ≥ 1: 2 molar ratio in methanolic solutions. The complexes were studied using spectral (UV-Vis,
FT-IR, EPR), magnetochemical, thermogravimetric methods and elemental analysis. In the complexes nadolol acts as a monoanionic
bidentate ligand coordinated to copper(II) through the NH-and the deprotonated OH-groups of its aminoalcohol fragment.
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3.
Maria-Gabriela Alexandru Tanja Cirkovic Velickovic Ioana Jitaru Sanja Grguric-Sipka Constantin Draghici 《Central European Journal of Chemistry》2010,8(3):639-645
This paper presents the synthesis of complex compounds of type [M(L1)2], where M(II)= Cu (1), Co (2), Zn (3), L1=2-aminothiazole-4-acetate and [Mn(L1)2(H2O)] (4) using ethyl 2-(2-aminothiazole-4-yl) acetate (L), and characterization by elemental analysis, magnetic susceptibilities,
IR, 1H-NMR, UV-Vis spectroscopy and for [Mn(L1)2(H2O)] also by X-ray diffraction. In vitro cytotoxicity studies were performed on human cervix adenocarcinoma, HeLa cells. The
antitumor selectivity was assessed using normal human peripheral blood mononuclear cells, PBMC as control.
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4.
Elham S. Aazam Amel F. EL Husseiny Peter B. Hitchcock Jemila M. Alshehri 《Central European Journal of Chemistry》2008,6(2):319-323
A binuclear copper complex [{Cu(L)2}2], C68H48Cu2N4O12C (where L is 4-methyl-7-(salicylideneamino)coumarin), has been synthesized and characterized using elemental analysis, molar
conductance measurements, and infrared, ultraviolet and ESR spectrosopy. The molecular structure of title compound, determined
by single-crystal X-ray diffraction studies, reveals that the two symmetric Cu(L)2 units are associated into a dimer by rather
long Cu...O bonds. The Cu(II) ions are bridged via the phenolic oxygen of one of the monomers and have distorted trigonal
bipyramidal conformation geometry. Within each monomer the two methylsubstituted coumarin skeletons are trans to one another,
but adopt a parallel arrangement with respect to the other monomer. Only half of the complex molecule can be found in the
asymmetric unit, Z′ = 0.5, the other half is generated by the symmetry centre.
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5.
Phase equilibria established in the PbO - BiVO4 system over the whole component concentration range up to 1000°C have been investigated. A phase diagram has been constructed
using DTA and XRD.
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6.
Jorge Luis Sague Doimeadios 《Central European Journal of Chemistry》2008,6(4):505-508
Herein, the first example of a co-crystal system formed by an imidazolium nitrate, a carbene precursor, and copper (II) nitrate,
{[Cu(NO3)2(H2O)2]L1(NO3)2} (1) (L1 = 1,1′-dibenzyl-3,3′-butyl-diimidazolium-2,2′-diylidene) is reported. These two building blocks are connected in the solid
state through hydrogen bonds to generate a three-dimensional supramolecular network.
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7.
Elena A. Reshetnyak Nataliia V. Ivchenko Nataliya A. Nikitina 《Central European Journal of Chemistry》2012,10(5):1617-1623
Photometric determination of aqueous Co(II), Cu(II), Ni(II) and Fe(III) was performed using indicator films prepared by immobilization
of 1-nitroso-2-naphthol-3,6-disulfonic acid disodium salt (NRS) into hardened photographic film. Immobilization was based
on electrostatic interaction of reagent and metal complexes with the gelatin. The isoelectric point pH of hardened gelatin
(4.46±0.04) was evaluated by viscometry. Co(II), Fe(III), Ni(II) form 1:3 complexes with NRS in gelatin at pH 2 and Cu(II)
forms 1:2 complexes. Their log β′ values were: Co-6.7, Fe-8.6, Cu-8.0, and Ni-6.4. The absorption maxima were: 370nm for NRS,
and 430nm, 470nm, 495nm and 720nm for complexes of Co(II), Ni(II), Cu(II) and Fe(III). An algorithm for their simultaneous
determination using the indicator films was developed. The detection limits were: clim(Co2+) = 0.45×10−5 M, clim(Fe3+) = 0.50×10−5 M, clim(Cu2+) = 0.67×10−5 M, clim(Ni2+) = 0.75×10−5 M,; and their sum clim(ΣMn+) = 0.82×10−5 M.
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8.
Radostina I. Alexandrova Tanya Zhivkova Marin Alexandrov Georgi Miloshev Milena Georgieva Ivayla N. Pantcheva Mariana Io. Mitewa 《Central European Journal of Chemistry》2012,10(5):1464-1474
The anticancer activity of monensic acid (MonH) and its biometal(II) complexes [M(Mon)2(H2O)2](M = Mg, Ca, Mn, Co, Ni, Zn) was evaluated against cultured human permanent cell lines established from glioblastoma multiforme (8MGBA) and cancers of the lung (A549), breast (MCF-7), uterine cervix (HeLa) and liver (HepG2). The viability and proliferation of the non-tumor human embryonic cell line Lep3 was also tested. The investigations were carried out using a thiazolyl blue tetrazolium bromide test, neutral red uptake cytotoxicity assay, crystal violet staining, colony forming method and double staining with acridin orange and propidium iodide. The results obtained reveal that the compounds applied at concentrations of 0.5–25 μg mL−1 for 24–72 h decrease the viability and proliferation of the treated cells in a time- and concentration-dependent manner. The metal(II) complexes studied (especially those of Co(II), Ni(II) and Zn(II)) have been found to express stronger cytotoxic and cytostatic activities than the non-coordinated monensic acid. The non-tumor human cell line showed strong chemosensitivity towards compounds tested comparable to that of cultured human tumor cell lines. 相似文献
9.
Abdülhadi Baykal Yüksel Köseoğlu Mehmet Şenel 《Central European Journal of Chemistry》2007,5(1):169-176
Heating hydrous manganese (II) hydroxide gel at 85 °C for 12 hours produces Mn3O4 nanoparticles. They were characterized by X-ray powder diffraction (XRD) and infrared spectroscopy (FTIR). The particle size
estimated from the SEM and X-ray peak broadening is approximately 32 nm, showing them to be nanocrystalline. EPR measurements
confirm a typical Mn2+signal with a highly resolved hyperfine structure.
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10.
The determination of paeoniforin, paeonol, and censenoside Rg1 in traditional Chinese medicinal preparations, Tze Po San Pien pills and Liuwen Dihuang pills has been investigated by micellar
electrokinetic capillary electrophoresis with borate buffer (20 mM), sodium dodecylsulfate (30 mM) and acetonitrile (20%)
as background electrolytes (pH 9.30), 20 kV applied voltage and 203 nm UV detection. The effects of SDS concentration, borate,
buffer pH, and organic modifier on electrophoretic behavior and separation are discussed. Regression equations revealed linear
relationships between the peak-area of each component and the content with the correlation coefficients from 0.9982 to 0.9999.
In addition, the levels of the active compounds in two kinds of traditional Chinese medicinal preparations were easily determined
with the recoveries from 93.1% to 108.2%.
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11.
Sandip A. Sadaphal Kiran F. Shelke Swapnil S. Sonar Murlidhar S. Shingare 《Central European Journal of Chemistry》2008,6(4):622-626
1-benzyl-3-methyl imidazolium hydrogen sulphate [bnmim][HSO4] was found to be an effective catalyst for the condensation reaction of indoles and derivatives with benzaldehydes in microwave
irradiation with lower reaction time and higher yields to give bis(indolyl) methanes.
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12.
Ayman Massoud F. Abou El-Nour H. Killa U. Seddik 《Central European Journal of Chemistry》2010,8(3):696-701
This work assesses the potential of an adsorptive material, Dowex 50w-x8, for the separation of indium ions from cadmium ions
in aqueous media. The adsorption behavior of Dowex 50 w-x8 for indium and cadmium ions was investigated. The effect of pH,
initial concentration of metal ions, the weight of resins, and contact time on the sorption of each of the metal ions were
determined. It was found that the adsorption percentage of the indium ions was more than 99% at pH 4.0. The result shows that
In (III) was most strongly extracted, while Cd(II) was slightly extracted at this pH value. The recovery of In(III) and Cd(II)
ions is around 98% using hydrochloric acid as the best eluent.
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13.
Petr Bělina Petra Šulcová Miroslav Trojan Pavel Mazurek 《Central European Journal of Chemistry》2007,5(3):706-714
New binary lanthanum-aluminum triphosphates were synthesized by thermal-condensation method from H3PO4, La2O3 and Al(OH)3. These pigments could be potentially used as special inorganic pigments; their corrosion-inhibition properties were widely
studied. Synthesis conditions were determined on the basis of DTA and TG measurements. The products were also characterized
by X-ray diffraction analysis. Physical properties — density by pycnometric method, particle size distribution, oil number
and critical pigment volume concentration (CPVC), pH and specific conductivity of their aqueous extracts were also determined.
相似文献
14.
Li-hua Yu Shou-min Zhang Xianzhi Guo Da Wang Shu-rong Wang Shi-hua Wu 《Central European Journal of Chemistry》2007,5(1):144-155
The Co-Pd/SiO2 and Co-Cu/SiO2 catalysts were prepared via solvated metal atom impregnation (SMAI) method and investigated for the Fischer-Tropsch (F-T)
synthesis. The catalysts contained 5wt.% Co and a weight ratio of Pd (or Cu) to Co of 1/30. XPS indicated that Co, Pd and
Cu were in metallic state. The results of XPS and magnetic measurements showed that Co and Pd (Cu) were alloyed. The Co particles
on the catalysts were very highly dispersed and they displayed superparamagnetic behavior. FT-IR indicated that the electrons
shifted from Cu and Pd to Co. Catalytic tests showed that CO hydrogenation rates followed the order Pd-Co > Cu-Co > Co.
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15.
An organic-inorganic composite, poly-o-anisidine Sn(IV) phosphate, was chemically synthesized by mixing ortho-anisidine into
gels of Sn(IV) phosphate with different mixing volume ratios. Studies on the effect of eluant concentration, elution behavior
and separation of metal ions were carried out to understand the ion-exchange capabilities. Due to Cd(II) selective nature
of composite, revealed by distribution studies, Cd(II) ion selective membrane electrode was fabricated. The analytical utility
of the electrode was established by employing it as an indicator electrode in electrometric titrations having fast response
time, 3–5s, and long life span of six months. Some physical parameters like self-diffusion coefficient (D0), activation energy (Ea) and entropy of activation (ΔS0) have been evaluated under conditions favoring a particle diffusion-controlled mechanism by studying ion-exchange kinetics.
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16.
Jinzhang Gao Dongyu Lv Wu Yang Xiaoxia Wei Jie Qu Hua Chen Hongxia Dai Jie Ren 《Central European Journal of Chemistry》2007,5(2):581-589
A convenient and sensitive method for determination of sulfanilamide (SNA) was described based on the Mn(II)-catalyzed oscillating
chemical reaction. Under optimum conditions, a linear relationship existed between the changes of oscillating period or amplitude
and the negative of logarithm of SNA concentration in the range of 4.27 × 10−8 mol ·L−1 ∼ 7.41 × 10−6 mol ·L−1 (RSD, 0.85%) and 9.33 × 10−8 mol ·L−1 ∼ 3.02 × 10−6 mol ·L−1 (RSD, 1.08%), respectively. The lower limit of detection was found to be 2.69 × 10−8 mol ·L−1 and 6.03 × 10−8 mol ·L−1, respectively.
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17.
Ksenija R. Kumrić Tatjana M. Trtić-Petrović Ljubiša M. Ignjatović Jožef J. Čomor 《Central European Journal of Chemistry》2008,6(1):65-69
Lutetium has been determined by differential pulse anodic stripping voltammetry in an acidic solution containing Zn-EDTA.
Lutetium (III) ions liberated zinc (II), which was preconcentrated on a hanging mercury drop electrode and stripped anodically,
resulting in peak current linearly dependent on lutetium (III) concentration. Less than 0.4 ng mL−1 lutetium could be detected after a 2 min deposition.
相似文献
18.
Maria M. Milanova Dimitar S. Todorovsky Christo C. Balarew Natalia L. Minkova Katya I. Ivanova 《Central European Journal of Chemistry》2007,5(1):13-19
The cocrystallization of Ce2(SO4)3 and La2(SO4)3 is studied in aqueous and H2SO4 (150 g/dm3) solutions at 25 °C and 64 °C. The effect of the formation of inner sphere sulfate complexes of the type LnSO
4
+
in determining the composition of the equilibrium phases is revealed.
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19.
Lyudmila A. Belyakova Oleksandra M. Shvets Diana Yu. Lyashenko 《Central European Journal of Chemistry》2008,6(4):581-591
The present work investigates the adsorptive interactions of Hg(II) ions in aqueous medium with hydroxylated silica, aminopropylsilica
and silica chemically modified by β-cyclodextrin. Batch adsorption studies were carried out with various agitation times and
mercury(II) concentrations. The maximum adsorption was observed within 15–30 min of agitation. The kinetics of the interactions,
tested with the model of Lagergren for pseudo-first and pseudo-second order equations, showed better agreement with first
order kinetics (k1 = 3.4 ± 0.2 to 5.9 ± 0.3 min−1). The adsorption data gave good fits with Langmuir isotherms. The results have shown that β-cyclodextrin-containing adsorbent
has the largest adsorption specificity to Hg(II): K
L
= 4125 ± 205 mmol−1. “β-cyclodextrin-NO3-” inclusion complexes with ratio 1: 1 and super molecules with composition C42H70O35 ⊎ 3 Hg(NO3)2 are formed on the surface of β-cyclodextrin-containing silica.
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20.
The reaction mechanism between AlX and HX (X = Br, Cl, and F) have been characterized in detail using DFT as well as the ab initio method. The reaction yielding AlX3 and molecular hydrogen was calculated to be highly exothermic. The present calculations also show that the possible routes
to the trihalides species start more favorable with the primary insertion product AlX2H than with the biadduct AlX(HX)2 one.
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