共查询到20条相似文献,搜索用时 15 毫秒
1.
S. A. Bychkova A. V. Katrovtseva E. V. Kozlovskii 《Russian Journal of Coordination Chemistry》2008,34(2):93-96
The process of complex formation of maleic acid (H2L) with the ions Zn2+, Ni2+, Co2+, Cu2+ was studied by potentiometric titration in a wide range of concentration ratios at 298 K and I = 0.1 mol/l (NaNO3). The moieties ZnL, CoL, NiL, NiL 2 2? , CuL, and CuL 2 2? were detected and their stability constants were determined. 相似文献
2.
Isothermal titration calorimetry has been used to determine the stoichiometry, formation constants and thermodynamic parameters
(ΔG
o, ΔH, ΔS) for the formation of the citrate complexes with the Mn2+, Co2+, Ni2+ and Zn2+ ions. The measurements were run in Cacodylate, Pipes and Mes buffer solutions with a pH of 6, at 298.15 K. A constant ionic
strength of 100 mM was maintained with NaClO4. The influence of a metal ion on its interaction energy with the citrate ions and the stability of the resulting complexes
have been discussed. 相似文献
3.
4.
O. Yu. Zelenin 《Russian Journal of Coordination Chemistry》2007,33(5):346-350
The formation of nickel citrate complexes was studied at ionic strength values of 0.1 and 0.3 mol/l (Et4NCl) and 298.15 K by potentiometric titration. The NiCit?, NiHCit, and NiH2Cit+ complexes were formed in a Ni2+ ion-citric acid (H3Cit) system. The thermodynamic formation constants of the nickel(II) citrate complexes were calculated in an aqueous solution at \(I = 0:\log \beta _{NiCit^ - }^0 \) = 6.86 ± 0.12 (Ni2+ + Cit3? ai NiCit?), logK 1 0 = 4.18 ± 0.10 (Ni2+ + HCit2? ai NiHCit), and logK 2 0 = 2.24 ± 0.11 (Ni2+ + H2Cit? ai NiH2Cit+). The spectral properties of the Ni2+-H3Cit system were studied by spectrometry. The conditions of calorimetric determination of the thermal effects of formation of the nickel citrate complexes in an aqueous solution were optimized on the basis of the calculated stability constants of the Ni(II) complexes with H3Cit. 相似文献
5.
Shiva Agarwal M. Teresa A. Reis M. Rosinda C. Ismael Jorge M. R. Carvalho 《Chemical Papers》2015,69(5):679-689
The extraction of copper from sulphuric/sulphate solutions using a hollow fibre module as contactor was studied. The aldoxime Acorga M5640 was used as an extractant. The effects on the extraction rate of the flow-rates, the concentrations of copper and extractant, pH, and the presence of Na2SO4 in the feed phase were investigated. The overall mass transfer coefficient for copper extraction was calculated from the experimental data and was compared with the value evaluated by the resistance in the series model. The extraction process was found to be governed by the diffusion in the boundary aqueous layer and also by the chemical reaction. The kinetic data obtained were used to simulate the extraction of copper with the pseudo-emulsion-based hollow fibre with strip dispersion technique. The accordance between the results thus calculated and the experimental data was found to be satisfactory, particularly for dilute feed solutions. 相似文献
6.
Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Michel Delamar Florence Babonneau Jacques Livage 《Journal of Sol-Gel Science and Technology》2007,41(1):3-10
A new insoluble solid functionalized ligand system bearing chelating ligand group of the general formula P-(CH2)3-N[CH2CONH(C6H4)NH2]2, where P represents [Si–O]
n
polysiloxane network, was prepared by the reaction of the immobilized diethyliminodiacetate polysiloxane ligand system, P-(CH2)3N(CH2CO2Et)2 with 1,2-diaminobenzene in toluene. 13C CP-MAS NMR, XPS and FTIR results showed that most ethylacetate groups (–COOEt) were converted into the amide groups (–N–C=O).
The new functionalized ligand system exhibits high capacity for extraction and removal of the metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+) with efficiency of 95–97% after recovery from its primary metal complexes. This functionalized ligand system formed 1:1
metal to ligand complexes. 相似文献
7.
T. D. Orlova A. V. Katrovtseva S. A. Bychkova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(5):808-811
The heat effects of complex formation between zinc(II) and nickel(II) ions and succinic acid were determined calorimetrically
at 298.15 K and several ionic strength values against the background of NaNO3. The standard thermodynamic characteristics of complex formation in aqueous solution were calculated. 相似文献
8.
The heats of formation of complexes in the glycyl-L-asparagine—Ni2+ system were determined by calorimetry in an aqueous solution at ionic strengths of 0.5, 1.0, and 1.5 (KNO3) and a temperature of 298.15 K. The thermodynamic characteristics of the formation of nickel complexes with dipeptide were determined. The influence of the ligand structure on the complexation thermodynamics in solutions was discussed.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 2, 2005, pp. 143–148.Original Russian Text Copyright © 2005 by Zelenin, Kochergina. 相似文献
9.
We have investigated the presence of foreign ions into the bulk structure and the external surfaces of aragonite using periodic
ab-initio methods. Four cations isovalent to Ca2+ were studied: Mg2+, Sr2+, Ba2+ and Zn2+. The calculations were performed at structures (bulk, surface) that contain four and eight CaCO3 units. Our results, at the Hartree-Fock level, show that the incorporation of those ions into aragonite depends strongly
on their size. Mg2+ and Zn2+, due to their smaller size, can substitute Ca2+ ions in the crystal lattice while the incorporation of Sr2+ and Ba2+ into aragonite is energetically less favoured. Examination of the [011], [110] and [001] surfaces of aragonite revealed that
the surface incorporation reduces the energetic cost for the larger ions. These systems provide challenging examples for most
shape analysis methods applied in Mathematical Chemistry. 相似文献
10.
M. K. Khosa P. T. Wood S. M. Humphrey W. T. A. Harrison 《Journal of Structural Chemistry》2015,56(6):1130-1135
The syntheses and crystal structures of the layered coordination polymers M(C8H8NO2)2 [M = Mn (1), Co (2), Ni (3) and Zn (4)] are described. These isostructural compounds contain centrosymmetric trans-MN2O4 octahedra as parts of infinite sheets; the ligand bonds to three adjacent metal ions in μ3-N,O,O′ mode from both its carboxylate O atoms and its amine N atom. In each case, weak intra-sheet N–H?O and C–H?O hydrogen bonds may help to consolidate the structure. Crystal data: 1, C16H16MnN2O4, M r = 355.25, monoclinic, P21/c (No. 14), a = 10.6534(2) Å, b = 4.3990(1) Å, c = 15.5733(5) Å, β = 95.1827(10)°, V = 726.85(3) Å3, Z = 2, R(F) = 0.026, wR(F 2) = 0.067. 2, C16H16CoN2O4, M r = 359.24, monoclinic, P21/c (No. 14), a = 10.6131(10) Å, b = 4.3374(4) Å, c = 15.3556(17) Å, β = 95.473(4)°, V = 703.65(12) Å3, Z = 2, R(F) = 0.041, wR(F 2) = 0.091. 3, C16H16N2NiO4, M r = 359.02, monoclinic, P21/c (No. 14), a = 10.6374(4) Å, b = 4.2964(2) Å, c = 15.2827(8) Å, β = 95.9744(14)°, V = 694.66(6) Å3, Z = 2, R(F) = 0.028, wR(F 2) = 0.070. 4, C16H16N2O4Zn, M r = 365.68, monoclinic, P21/c (No. 14), a = 10.6385(5) Å, b = 4.2967(3) Å, c = 15.2844(8) Å, β = 95.941(3)°, V = 694.89(7) Å3, Z = 2, R(F) = 0.038, wR(F 2) = 0.107. 相似文献
11.
Xuefang Zheng Wenlong Hou Qi Lian Haixia Wu 《Russian Journal of General Chemistry》2016,86(4):915-918
Graphene oxide (GO) has been prepared by the modified Hummers method using graphite as starting material. The product was studied by the X-ray diffraction (XRD), Raman spectroscopic, transmission electron microscopic (TEM), and scanning electron microscopic (SEM) analyses. Adsorption capacity of GO for heavy metal ions was studied for the example of the Ni2+ ions and the adsorption kinetics and adsorption isotherm were determined. It was shown that the adsorption equilibrium curves are adequately described by the Langmuir equation. 相似文献
12.
N. V. Shul’ga I. L. Shashkova N. V. Mil’vit A. I. Rat’ko 《Russian Journal of Applied Chemistry》2007,80(8):1304-1308
Kinetic characteristics of the interaction of trisubstituted calcium phosphate Ca3(PO4)2 · xH2O with Cu2+, Zn2+, Co2+, and Pb2+ ions in aqueous solutions were studied. 相似文献
13.
The efficiency of calcium and magnesium phosphates of different compositions in the extraction of Cu2+, Zn2, and Co2+ ions from aqueous solutions was studied. 相似文献
14.
The absorption of Fe3+ ions from Fe3+-Zn2+ mixture with zinc and calcium phosphates was studied. 相似文献
15.
G. G. Gorboletova L. A. Kochergina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(7):1082-1087
The heat effects of interaction between solutions of D,L-threonine and Ni(NO3)2 were measured by direct calorimetry at 298.15 K and ionic strength values of from 0.5 to 1.5 (KNO3). The heat effects of formation of the NiL+, NiL2, and NiL 3 ? complexes were calculated. The influence of background electrolyte concentration on the heats of complex formation in the Ni2+-D,L-threonine system was studied. The standard heat effects of formation of Ni2+ complexes with D,L-threonine were obtained by extrapolation to zero ionic strength. The standard enthalpies of formation of NiL+, NiL2, and NiL 3 ? in aqueous solution were calculated. 相似文献
16.
Daiki Asakawa Edwin De Pauw 《Journal of the American Society for Mass Spectrometry》2016,27(7):1165-1175
Electron capture dissociation (ECD) and electron transfer dissociation (ETD) in metal-peptide complexes are dependent on the metal cation in the complex. The divalent transition metals Ni2+, Cu2+, and Zn2+ were used as charge carriers to produce metal-polyhistidine complexes in the absence of remote protons, since these metal cations strongly bind to neutral histidine residues in peptides. In the case of the ECD and ETD of Cu2+-polyhistidine complexes, the metal cation in the complex was reduced and the recombination energy was redistributed throughout the peptide to lead a zwitterionic peptide form having a protonated histidine residue and a deprotonated amide nitrogen. The zwitterion then underwent peptide bond cleavage, producing a and b fragment ions. In contrast, ECD and ETD induced different fragmentation processes in Zn2+-polyhistidine complexes. Although the N–Cα bond in the Zn2+-polyhistidine complex was cleaved by ETD, ECD of Zn2+-polyhistidine induced peptide bond cleavage accompanied with hydrogen atom release. The different fragmentation modes by ECD and ETD originated from the different electronic states of the charge-reduced complexes resulting from these processes. The details of the fragmentation processes were investigated by density functional theory. 相似文献
17.
P. Staszczuk M. Majdan S. Pikus D. Sternik M. Błachnio 《Journal of Thermal Analysis and Calorimetry》2008,94(3):655-662
Complex studies of physicochemical properties of pure and modified of aluminia oxides samples are presented. The presence
of Mn2+ and Ni2+ modifiers on the aluminium oxide surface causes increase in water adsorption capacity and decrease in benzene and n-octane adsorption. This is due to decrease of specific surface area, volume and radius of pores as a result of surface impregnation
and microcrystal formation during modification with manganese and nickel chlorides. Microcrystal formation on the surface
and porosity decrease as confirmed by AFM, EDX and powder diffraction studies using automated diffractometer by step scanning.
From the Q-TG and Q-DTG data, the energies of liquid desorption from the surface of the samples and the functions of desorption,
energy distribution were calculated. High degree of nonlinearity of the functions resulting from great heterogeneity of the
studied surface was found. Adsorption of cations creates more homogeneous surface in aluminium oxide, and it is responsible
for the change in adsorbate molecule interaction energy and changes mechanism of adsorption and desorption as well as thickness
and structure of the adsorbed film. From the experimental data some parameters characterizing adsorption properties and porosity
of the studied samples were determined using the complex measuring methods (thermal analysis, sorptometry, porosimetry, AFM
and EDX). 相似文献
18.
Ruizhuo Ouyang Tianyu Zong Yongfu Su Pengpeng Jia Shuang Zhou Yang Yang Kai Feng Haizhou Chang Ying Chen Yuefeng Zhao Fei Xiong Yuqing Miao 《Journal of Solid State Electrochemistry》2017,21(10):2887-2898
A new type of Ni2+-loaded MWCNT composite was prepared by mixing carboxylated multiwalled carbon nanotubes (MWCNTs) and Ni2+ ions and allowing them to interact electrostatically. The resulting composite was subsequently used as an electrocatalyst for glucose (Glu) oxidation. Compared with electrodes modified through the addition of free Ni2+ ions or MWCNTs, the Ni2+/MWCNT composite electrode showed greatly improved properties such as hydrophilicity. Investigations of the Ni2+/MWCNT composite electrode via inductively coupled plasma atomic emission spectroscopy and nitrogen adsorption–desorption isotherms verified that Ni2+ ions had been adsorbed onto the surfaces of the MWCNTs in the composite. As expected, a Ni2+/MWCNT composite-based sensor showed extraordinary electrocatalytic performance in Glu oxidation. In the concentration range 0–4.3 mM, a good linear relationship between the Glu added and the current generated was observed, with a correlation coefficient (R 2) of 0.9988. The detection limit and sensitivity were calculated to be 0.081 μM and 2285 μA mM?1 cm?2, respectively. Finally, the new method was successfully applied to determine the Glu in a human blood sample. Recoveries of >100%, indicative of high reliability, accuracy, and precision, were obtained. 相似文献
19.
L. S. Nikolaeva A. N. Semenov L. I. Burova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(12):2039-2046
Chemical equilibria in the high-molecular-weight heparin (Na4hep)-arginine (HArg)-H2O-NaCl and MCl2-Na4hep-HArg-H2O-NaCl systems of electrolytes (M = Ca2+, Mg2+) were calculated by the method of mathematical simulation of chemical equilibria from representative planned pH-metric titration
experiment at 2.30 ≤ pH ≤ 10.50 in a physiological solution medium in the presence of 0.154 M NaCl as a background electrolyte
at 37°C. The initial concentrations of the basic components were n × 10−3 M (n ≤ 4). 相似文献
20.
Saeedeh Hashemian 《Russian Journal of Inorganic Chemistry》2011,56(3):397-401
The imidazol side group of histidine has two nitrogen atoms capable of being protonated or participating in metal binding.
Hence, histidine can take on various metal-bound and protonated forms in proteins. Because of its variable structural state,
histidine often functions as a key amino acid residue in enzymatic reactions. Ab initio (HF and MP2) calculations were done
in modeling the cation (H+, Li+, Na+, K+, Mg2+, Ca2+) interaction with side chain of histidine. The region selectivity of metal ion complexation is controlled by the affinity
of the side of attack. In the imidazol unite of histidine the ring nitrogen has much higher metal ion (as well as proton)
affinity. The complexation energies with the model systems decrease in the following order: Mg2+ > Ca2+ > Li+ > Na+ > K+. The variation of the bond lengths and the extent of charge transfer upon complexation correlate well with the computed interaction
energies. 相似文献