共查询到20条相似文献,搜索用时 31 毫秒
1.
《Analytical letters》2012,45(8):575-584
Abstract The complexations of a new ligand, o-(2-thiazolylazo)-4-ethylphenol(TAEP) with Ca(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hq(II) and Pb(II) have been studied by potentiometric titrations, at 25.0 ± 0.2°C and an ionic strength of 0.1 in 30% v/v dioxane-water mixture. The dissociation constant and spectral data of TAEP and formation constants of the complexes containing various molar ratios of metal ion to ligand, are reported. It is observed that Ca(II) forms only an ML complex in any molar ratios, whereas other metal ions react in two steps forming ML and ML2 complexes in a 1:3 molar ratio. In the case of 1:1 and 1:2 molar ratios, Mn(II), Co(II), Cd(II) and Hg(II) seemed to form bi- or poly-nuclear complexes because of slightly different formation curves from those of 1:3 molar ratio. The sequence of the first successive formation constant is Cu > Hg > Ni > Pb > Co > Zn > Cd > Mn > Ca, showing Mellor-Maley's order. Further correlation is shown between the formation constants and the second ionization potentials of the metals. 相似文献
2.
Potentiometric Study of Tetracycline and Oxytetracycline with some Metal Ions of Biological Interest
《Analytical letters》2012,45(5):413-422
Abstract The stepwise metal-ligand stability constants of tetracycline and oxytetraoycline chelates with Mg(II), Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Cu(II), Zn(II), Zr(II) and Sn(II) have been determined using the Bjerrum-Calvin titration technique as employed by Irving and Rossotti. Protonation constant of the ligand and stability constants of the respective metal complexes have been determined at constant temperature (25°C) and ionic strength (0.1 M KCl). The general order of overall stability constant values have been found to be: Zr(IV) > Fe(III) > Co(II) > Zn(II) > Mg(II) > Mn(II) > Ni(II) > Sn(II) > Tn(II) > Cr(II). The rign values of the atability constanta are attricutel to the Ligands, which are stronger as an acid and weaser as a oase. 相似文献
3.
Mohamed M. Shoukry Ihsan M. Kenawy Afkar K. Abdel Hadi Eman M. Shoukry 《Journal of Chemical Sciences》1988,100(5):381-388
The formation constants of salicyl-4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one (SAAP) complexes with 3d transition metal
ions [Cu(II), Ni(II), Co(II), Zn(II) and Mn(II)] have been determined in 60% ethanol-water medium ofμ = 0.1M (NaCl) at 25°C. It is observed that the formation constants for chelates with 3d transition metals follow the order
Mn(II) < Co(II) < Ni(II) < Zn(II) < Cu(II). The effects of metal ions, ionic radii, electronegativities and ionization potentials
on chelate formation constants are discussed.
Complexes of UO2(II) and Pd(II) have been synthesized and characterised by elemental analysis, electrolytic conductance, IR spectra and magnetic
measurements. The ligand forms the complexes PdLCl and UO2L2,2H2O, where L is a uninegatively charged tridentate ligand (ONO donor sets). 相似文献
4.
Polychelates of Mn(II), Fe(II), Co(II), Ni(II), and Cu(II) with 4,4′-dihydroxy-3,3′-diacetylbiphenyl-dithioxamide (DDBDO)
have been prepared. Their structures were determined by visible reflectance spectroscopy and magnetic measurements in conjunction
with thermogravimetric and IR measurements. Elemental analysis indicates a 1∶1 metal-ligand stoichiometry and the association
of water molecules with the central metal. The decomposition temperature of the chelates is in the order Ni(II)>Fe(II)>Co(II)>Mn(II)>Cu(II).
Thermal activation energies (E
a
), calculated with the help of Freeman-Carroll and Sharp-Wentworth methods, are in agreement with each other. The polychelates
were found to be semiconductive, and the activation energy obtained from semiconducting behavior follows the order Co(II)>Ni(II)>Fe(II)>Cu(II)>Mn(II).
The probable structure, such as six coordinated octahedral for Mn(II) and Fe(II) polychelates and four coordinated square
planar for Co(II), Ni(II), and Cu(II) polychelates, have been suggested. 相似文献
5.
Conditions for the preparation of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) 3-methyladipates were investigated and their qualitative
composition and magnetic moments were determined. The IR spectra and powder diffraction patterns of the complexes prepared
of the general formula M(C7H10O4)·nH2O (n=0-11) were recorded and their thermal decomposition in air were studied. During heating the hydrated complexes are dehydrated
in one (Co, Ni) or two steps (Mn, Zn) losing all crystallization water molecules (Co, Ni) or some water molecules (Mn, Zn)
and then anhydrous (Co, Ni, Cu) or hydrated complexes (Mn, Zn) decompose directly to oxides (Mn, Co, Zn) or with intermediate
formation the mixture of M+MO (Ni, Cu). The carboxylate groups are bidentate (Mn, Co, Ni, Cu) or monodentate (Zn). The complexes
exist as polymers. The magnetic moments for the paramagnetic complexes of Mn(II), Co(II), Ni(II) and Cu(II) attain values
5.48, 4.49, 2.84 and 1.45 B.M., respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
K. M. Ibrahim I. M. Gabr G. M. Abu El-Reash R. R. Zaky 《Monatshefte für Chemie / Chemical Monthly》2009,100(1):625-632
Abstract
Acetone [N-(3-hydroxy-2-naphthoyl)] hydrazone (H2AHNH) has been prepared and its structure confirmed by elemental analysis and 1H NMR spectroscopy. It has been used to produce diverse complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and U(VI)O2 ions. The complexes obtained have been investigated by thermal analysis, spectral studies (1H NMR, IR, UV–visible, ESR), and magnetic measurements. IR spectra suggest that H2AHNH acts as a bidentate ligand. The electronic spectra of the complexes and their magnetic moments provide information about geometries. The ESR spectra give evidence for the proposed structure and the bonding for some Cu(II) complexes. Thermal decomposition of the Ni(II) and Cu(II) complexes afforded metal oxides as final products. Kinetic data were obtained for each stage of thermal degradation of some of the complexes using the Coats–Redfern method. The formation of complexes in solution was studied pH-metrically and the order of their stability constants (log K) was found to be U(VI)O2 > Cu(II) > Zn(II) > Ni(II) > Cd(II) > Co(II). Antimicrobial and eukaryotic DNA studies were carried out. 相似文献7.
Kalagouda B. Gudasi Ramesh S. Vadavi Rashmi V. Shenoy Manjula S. Patil Siddappa A. Patil 《Transition Metal Chemistry》2005,30(5):569-574
Complexes of Co(II), Ni(II), Cu(II), Mn(II), Zn(II) and Cd(II) with N,N′-bis(2-hydroxyphenyl)pyridine-2,6-dicarboxamide have been synthesized and characterized by elemental analysis, conductivity measurements, spectral (electronic, i.r., n.m.r. and e.p.r.), electrochemical and thermal studies. I.r. studies show that the ligand behaves in an ambidentate way. It coordinates through the pyridine nitrogen, two amide oxygens and two phenolic oxygens in the Co(II), Ni(II), and Cu(II) complexes, whereas in the Mn(II), Zn(II) and Cd(II) complexes it coordinates through the pyridine nitrogen, two uncharged amide nitrogens and two-phenolic oxygens under similar experimental conditions. 相似文献
8.
R. A. Alieva F. G. Pashaev A. G. Gasanov K. T. Mahmudov 《Russian Journal of Inorganic Chemistry》2009,54(9):1407-1411
Effective charges of atoms in tautomeric forms (enol-azo, keto-azo, hydrazo) of 3-(4-chlorophenylazo) pentane-2,4-dione (L) have been determined by MO LCAO in the Hückel approximation. The complex formation of a series of metals with L in aqueous ethanol has been investigated by potentiometric and conductometric titration. Based on the results of potentiometric
titration, the standard thermodynamic functions of complex formation have been established. They vary in the following order:
$
\begin{gathered}
\left| {\Delta G^0 } \right|:Fe > Cu > Co > Ni > UO_2 > Cd > Zn > Mn > Mg > Ca, \hfill \\
\left| {\Delta H^0 } \right|:Fe > Cu > UO_2 > Ni > Co > Zn > Cd > Mn > Mg > Ca, \hfill \\
\Delta S^0 :Ca > Mg > Mn > Cd > Co > Zn > Ni > Cu > Fe > UO_2 . \hfill \\
\end{gathered}
$
\begin{gathered}
\left| {\Delta G^0 } \right|:Fe > Cu > Co > Ni > UO_2 > Cd > Zn > Mn > Mg > Ca, \hfill \\
\left| {\Delta H^0 } \right|:Fe > Cu > UO_2 > Ni > Co > Zn > Cd > Mn > Mg > Ca, \hfill \\
\Delta S^0 :Ca > Mg > Mn > Cd > Co > Zn > Ni > Cu > Fe > UO_2 . \hfill \\
\end{gathered}
相似文献
9.
A study of the complexes originated by U(VI), Cu(II), Pb(II), Ni(II), Co(II), Zn(II), Cd(II), Mn(II), Ca(II), Mg(II), Ba(II), and Sr(II), and SPADNS (trisodium salt of 2-(p-sulfophenylazo)-1, 8-dihydroxynaphthalene-3,6-disulfonic acid) has been made by means of spectrophotometric and potentiometric methods. The dissociation constants of the ligand and the formation constants of the metal ion-SPADNS complexes have been determined at 25 ± 0.1 °C and ionic strength 0.1 (NaClO4). 相似文献
10.
K. M. Ibrahim I. M. Gabr G. M. Abu El-Reash R. R. Zaky 《Monatshefte für Chemie / Chemical Monthly》2009,140(6):625-632
Abstract Acetone [N-(3-hydroxy-2-naphthoyl)] hydrazone (H2AHNH) has been prepared and its structure confirmed by elemental analysis and 1H NMR spectroscopy. It has been used to produce diverse complexes with Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and U(VI)O2 ions. The complexes obtained have been investigated by thermal analysis, spectral studies (1H NMR, IR, UV–visible, ESR), and magnetic measurements. IR spectra suggest that H2AHNH acts as a bidentate ligand. The electronic spectra of the complexes and their magnetic moments provide information about
geometries. The ESR spectra give evidence for the proposed structure and the bonding for some Cu(II) complexes. Thermal decomposition
of the Ni(II) and Cu(II) complexes afforded metal oxides as final products. Kinetic data were obtained for each stage of thermal
degradation of some of the complexes using the Coats–Redfern method. The formation of complexes in solution was studied pH-metrically
and the order of their stability constants (log K) was found to be U(VI)O2 > Cu(II) > Zn(II) > Ni(II) > Cd(II) > Co(II). Antimicrobial and eukaryotic DNA studies were carried out.
Graphical abstract
相似文献
11.
The coordination compounds obtained by reaction of hot solutions of dipicolinic acid with the carbonates of the divalent metal ions manganese(II), iron(II), cobalt(II), nickel(II), copper(II) and zinc(II) are studied using TG, DSC and HTRS techniques. For the thermal stability a sequence Mn > Fe > Zn > Co > Ni > Cu may be observed. This series is compared with the similar series obtained with isocinchomeronic acid. The thermal stability is, for each metal of the series, isocinchomeronic > dipicolinic. Thermal stability is discussed in terms of the intermolecular bonds, of the structures and of the stability constants of the complexes examined. 相似文献
12.
Conditions for the preparation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II)3,3-dimethylglutarates were investigated
and their quantitative composition, solubility in water at 293 K and magnetic moments were determined. IR spectra and powder
diffraction patterns of the complexes prepared with general formula MC7H10O4⋅nH2O (n=0−2) were recorded and their thermal decomposition in air were studied. During heating the hydrated complexes of Mn(II),Co(II),
Ni(II) and Cu(II) are dehydrated in one step and next all the anhydrous complexes decompose to oxides directly (Mn, Co, Zn)
or with intermediate formation free metal (Ni,Cu) or oxocarbonates (Cd). The carboxylate groups in the complexes studied are
bidentate. The magnetic moments for the paramagnetic complexes of Mn(II), Co(II), Ni(II) and Cu(II)attain values 5.62, 5.25,
2.91 and 1.41 M.B., respectively.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
S. S. Konstantinović B. C. Radovanović Z. B. Todorović S. B. Ilić B. V. Konstantinović 《Chemical Papers》2007,61(6):485-489
Metal complexes of some divalent metal ions (Co, Ni, Cu, Zn, Hg, and Pd) with isatin-β-thiosemicarbazone (ITS) as the Schiff base have been investigated potentiometrically and spectrophotometrically. The dissociation
constants of the ligand and formation constants of the metal complexes, as well as the corresponding thermodynamic functions
(ΔG, ΔH and ΔS) have been determined at different temperatures in ethanol—water solution. The full stability constants were also evaluated
spectrophotometrically by the Job method. The experimental results indicate that Cu(II), Zn(II), Pd(II), and Hg(II) form one-to-one
molecular complexes (ML) with the studied ligand, whereas Co(II) and Ni(II) form both ML and ML2 species. 相似文献
14.
Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 3-methylglutarates were prepared as solids with general formula MC6 H8 O4 ×n H2 O, where n =0–8. Their solubilities in water at 293 K were determined (7.0×10−2 −4.2×10−3 mol dm−3 ). The IR spectra were recorded and thermal decomposition in air was investigated. The IR spectra suggest that the carboxylate
groups are mono- or bidentate. During heating the hydrated complexes lose some water molecules in one (Mn, Co, Ni, Cu) or
two steps (Cd) and then mono- (Cu) or dihydrates (Mn, Co, Ni) decompose to oxides directly (Mn, Cu, Co) or with intermediate
formation of free metals (Co, Ni). Anhydrous Zn(II) complex decomposes directly to the oxide ZnO.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
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
16.
Conditions for the preparation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 4-methylphthalates were investigated and
their composition, solubility in water at 295 K and magnetic moments were determined. IR spectra and powder diffraction patterns
of the complexes prepared with molar ratio of metal to organic ligand of 1.0:1.0 and general formula: M [ CH3C6H3(CO2)2]·nH2o (n=1-3) were recorded and their decomposition in air were studied. During heating the hydrated complexes are dehydrated in one
(Mn, Co, Ni, Zn, Cd) or two steps (Cu) and next the anhydrous complexes decompose to oxides directly (Cu, Zn), with intermediate
formation of carbonates (Mn, Cd), oxocarbonates (Ni) or carbonate and free metal (Co). The carboxylate groups in the complexes
studied are mono- and bidentate (Co, Ni), bidentate chelating and bridging (Zn) or bidentate chelating (Mn, Cu, Cd). The magnetic
moments for paramagnetic complexes of Mn(II), Co(II), Ni(II) and Cu(II) attain values 5.92, 5.05, 3.36 and 1.96 M.B., respectively.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Vovk T. V. Kovalchukova O. V. Zaitsev B. E. Strashnova S. B. Belskii V. K. Stash A. I. 《Russian Journal of Coordination Chemistry》2003,29(4):291-296
Crystal structure of 2,3-dihydroxypyridine (H2L) is determined. Mn(HL)Cl · H2O, Co(HL)Cl · 2H2O, Cu(HL)Cl, Ni(HL)OH · H2O, and Zn(HL)OH · H2O complexes are synthesized by reacting Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) chlorides with H2L in ethanol solutions and identified. In these complexes, 2,3-dihydroxypyridine is involved in coordination as a monoanion. Spectral parameters of neutral and anionic forms of a ligand are determined and the acidity and complex formation constants are calculated. The compositions of complexes are established. 相似文献
18.
《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):863-879
Abstract Catalase‐like activity of metal complexes of various crosslinked polystyrene‐supported glycines were carried out and correlated with the nature of crosslinking agent in the polymer support. Polystyrenes with 2 mol% divinyl benzene (DVB), ethylene glycol dimethacrylate (EGDMA), and 1,6‐hexanediol diacrylate (HDODA) crosslinking were used as polymer supports. Glycine functions were incorporated to the chloromethylpolystyrenes by polymer analogues reactions and complexed with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) ions. The metal uptake varied in the order: Cu(II) > Cr(III) > Mn(II) > Co(II) > Fe(III) > Ni(II) > Zn(II), and extent of metal uptake by various crosslinked systems varied with the nature of crosslinking agent. The polymeric ligands and the metal complexes were characterized by various analytical techniques. The catalytic activities of these metal complexes were investigated towards the decomposition of hydrogen peroxide and was found to decrease in the order: Co(II) > Cu(II) > Ni(II) > Cr(III) > Fe(III) > Mn(II) > Zn(II). With increasing rigidity of the crosslinking agent the catalytic activity also decreased. 相似文献
19.
Spectral,
magnetic and thermal investigations of some d-electron
element 3-methoxy-4-methylbenzoates
Conditions
for the preparation of Mn(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) 3-methoxy-4-methylbenzoates
were investigated and their quantitative composition and magnetic moments
were determined. The IR spectra and powder diffraction patterns of the complexes
prepared of general formula M(C9H9O3)2·nH2O (n=2
for Mn, Co n=1 for Ni, Cu, n=0
for Zn, Cd) were prepared and their thermal decomposition in air was studied.
Their solubility in water at 293 K is of the order 10–2
(Mn)–10–4 (Cu) mol dm–3.
IR spectra of the prepared 3-methoxy-4-methylbenzoates suggest that carboxylate
groups are bidentate bridging. The magnetic moments for the paramagnetic complexes
of Mn(II), Co(II), Ni(II) and Cu(II) attain values 5.50, 4.45, 3.16 and 1.79
B. M., respectively. During heating the hydrated complexes lose crystallization
water molecules in one step and then the anhydrous complexes decompose directly
to oxides MO and Mn3O4. Only Co(II) complex decomposes to Co3O4
with intermediate formation CoO. 相似文献
20.
S. Berto M. C. Bruzzoniti R. Cavalli D. Perrachon E. Prenesti C. Sarzanini F. Trotta W. Tumiatti 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):631-636
In this study, a new aqueous insoluble ionic β-cyclodextrin polymer (PYR), synthesized by reaction of β-cyclodextrin with
pyromellitic anhydride [1], is characterized by IR spectroscopy, showing typical cyclodextrin and carboxylic absorptions. pH-metric titrations of the
acidic functions with standard NaOH solutions followed by a refinement of protonation constants, with specific software for
equilibrium in solution, have been performed. Through this approach, the pK
a values of the functional groups have been calculated. The complexation capabilities of PYR towards metal ions [Al(III), Mn(II),
Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II), Pt(IV), Tl(I), and U(IV)] have been evaluated in aqueous solution (pH 3–5).
The retention is mainly pH dependent and higher than 70% for Al(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II)
and U(IV). For Tl(I) and Pt(IV) the retention is about 60% and 40% respectively. 相似文献
|