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1.
A new coumarin-based sensor molecule (L1) has been synthesized and this was found to bind calcium and magnesium ions more effectively as compared to other alkali/alkaline earth/lanthanide and certain transition metal ions. A significant enhancement in fluorescence intensity was observed on binding to Ca2+ and Mg2+ ions; while a minor quenching was observed for weakly bound Hg2+, Ni2+, Fe3+, and Co2+ ions. PET process, coupled with the ICT process, is proposed to explain the observed spectral response. 相似文献
2.
Chen X Fung YM Chan WY Wong PS Yeung HS Chan TW 《Journal of the American Society for Mass Spectrometry》2011,22(12):2232-2245
Electron capture dissociation (ECD) of model peptides adducted with first row divalent transition metal ions, including Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+, were investigated. Model peptides with general sequence of ZGGGXGGGZ were used as probes to unveil the ECD mechanism of
metalated peptides, where X is either V or W; and Z is either R or N. Peptides metalated with different divalent transition
metal ions were found to generate different ECD tandem mass spectra. ECD spectra of peptides metalated by Mn2+ and Zn2+ were similar to those generated by ECD of peptides adducted with alkaline earth metal ions. Series of c-/z-type fragment ions with and without metal ions were observed. ECD of Fe2+, Co2+, and Ni2+ adducted peptides yielded abundant metalated a-/y-type fragment ions; whereas ECD of Cu2+ adducted peptides generated predominantly metalated b-/y-type fragment ions. From the present experimental results, it was postulated that electronic configuration of metal ions
is an important factor in determining the ECD behavior of the metalated peptides. Due presumably to the stability of the electronic
configuration, metal ions with fully-filled (i.e., Zn2+) and half filled (i.e., Mn2+) d-orbitals might not capture the incoming electron. Dissociation of the metal ions adducted peptides would proceed through
the usual ECD channel(s) via “hot-hydrogen” or “superbase” intermediates, to form series of c-/z
•- fragments. For other transition metal ions studied, reduction of the metal ions might occur preferentially. The energy liberated
by the metal ion reduction would provide enough internal energy to generate the “slow-heating” type of fragment ions, i.e.,
metalated a-/y- fragments and metalated b-/y- fragments. 相似文献
3.
Anoop Kelkar Amrit Prakash Mohd. Afzal J. P. Panakkal H. S. Kamath 《Journal of Radioanalytical and Nuclear Chemistry》2010,284(2):443-449
An ion chromatographic method has been developed for the determination of traces of Li+, Na+, K+, Ca2+, Mg2+, Sr2+, Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+, Mn2+ in UO2, ThO2 powders and sintered (Th,U)O2 pellets. This new method utilizes poly-(butadiene-maleic acid) (PBDMA) coated silica cation exchange column and mixed functionality
column of anion and cation exchange to achieve the separation of alkali, alkaline earths and transition metal ions, respectively.
It involves matrix separation after sample dissolution by solvent extraction with TBP (tri butyl phosphate)-TOPO (tri octyl
phosphine oxide)/CCl4. Interference of transition metal ions in the determination of alkali, alkaline earth metal ions are removed by using pyridine
2,6-dicarboxylic acid (PDCA) in the tartaric acid mobile phase. Mobile phase composition is optimized for the base line separation
of alkali, alkaline earth and transition metal ions. Linear calibration graphs in the range 0.01–20 μg mL−1 were obtained with regression coefficients better than 0.999. The respective relative standard deviations were also determined.
Recoveries of the spiked samples are within ±10% of the expected value. The developed method is authenticated by comparison
with certified standards of UO2 and ThO2 powders. 相似文献
4.
B. G. Ershov 《Russian Chemical Bulletin》1998,47(10):1905-1909
The radiation-chemical reduction of Co2+ ions in an aqueous solution of Co(ClO4)2 containing sodium formate was studied. Stable metal sols containing spherical particles with a diameter of 2–4 nm are formed
under γ-irradiation in the presence of polyacrylate as the stabilizing additive. An aqueous solution of colloidal cobalt has
an optical absorption that increrases smoothly in the UV region without a maximum to 200 nm (ɛ200=1.3·104 mol-1 L cm-1). It is established that the radiation-chemical reduction of the Co2+ ions occursvia an autocatalytic mechanism. The metal sols catalyze the reduction of the Co2+ ions by Co2
− radical ions formed under irradiation. The properties of the sols were studied, and it is shown that they are readily oxidized
by hydrogen peroxide and other oxidants. The mechanism of chemical reactions involving the sols is discussed.
Tranalated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1959–1964, October, 1998. 相似文献
5.
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
6.
A. Sarkar Shweta Hegde T. Mukherjee S. Kapoor 《Research on Chemical Intermediates》2010,36(3):309-318
The effect of silver ions and silver nanoparticles on the rate of polymerization of acrylamide and N-isopropylacylamide was investigated. Composites of silver particles of diameter around 30 nm and polyacrylamide were prepared
by the photochemical method in the absence of any photosensitizer. The particles formed were characterized by UV–visible spectrophotometry,
XRD, and TEM. It was shown that the presence of metal ions such as Ag+, Co2+, and Ni2+ in the acrylamide monomer is essential for photoinduced polymerization. 相似文献
7.
Wiesława Ferenc Agnieszka Walków-Dziewulska Maria Wojciechowska J. Sarzyński 《Journal of Thermal Analysis and Calorimetry》2006,86(2):359-364
Physico-chemical properties of 4-chloro-2-nitrobenzoates of Co(II),
Ni(II), and Cu(II) were studied. The complexes were obtained as mono- and
trihydrates with a metal ion to ligand ratio of 1:2. All analysed 4-chloro-2-nitrobenzoates
are polycrystalline compounds with colours depending on the central ions:
pink for Co(II), green for Ni(II), and blue for Cu(II) complexes. Their thermal
decomposition was studied only in the range of 293–523 K, because it
was found that on heating in air above 523 K 4-chloro-2-nitrobenzoates decompose
explosively. Hydrated complexes lose crystallization water molecules in one
step and anhydrous compounds are formed. The final products of their decomposition
are the oxides of the respective transition metals. From the results it appears
that during dehydration process no transformation of nitro group to nitrite
takes place. The solubilities of analysed complexes in water at 293 K are
of the order of 10–4–10–2
mol dm–3. The magnetic moment values of Co2+,
Ni2+ and Cu2+ ions in
4-chloro-2-nitrobenzoates experimentally determined at 76–303 K change
from 3.89 to 4.82 μB for Co(II) complex, from 2.25
to 2.98 μB for Ni(II) 4-chloro-2-nitrobenzoate,
and from 0.27 to 1.44 μB for Cu(II) complex. 4-chloro-2-nitrobenzoates
of Co(II), and Ni(II) follow the Curie–Weiss law. Complex of Cu(II)
forms dimer. 相似文献
8.
Yu. I. Tarasevich D. A. Krysenko V. E. Polyakov E. V. Aksenenko 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2008,82(9):1506-1511
Direct calorimetric measurements were used to determine the heats of exchange of the Mn2+, Co2+, Cu2+, and Ni2+ cations on the Na form of clinoptilolite over the entire range of solid phase fillings with sorbed cations. In parallel, ion exchange isotherms for the systems were measured by the sorption-analytic method. The integral free energies and entropies of ion exchange were calculated. It was shown that the solution phase of the clinoptilolite-electrolyte solution two-phase system contributed significantly to the total thermodynamic characteristics of ion exchange. The differentiation of the dependence of the integral enthalpy on the degree of filling was performed to show that the clinoptilolite structure contained at least two types of exchange sites having different interaction energies with transition metal ions. 相似文献
9.
Najah Cheriaa Rym Abidi Jacques Vicens 《Journal of inclusion phenomena and macrocyclic chemistry》2008,60(3-4):303-312
Four imidazolyl acetamido p-tert-butylcalix[4]arenes 5–8 have been prepared by reacting the corresponding methyl esters derivatives 1–4 with histamine in 1:1 mixture of methanol:toluene. The yields ranged from 56 to 68%. 5–8 have been shown to be in cone conformation. The complexation behaviour of 5–8 towards monovalent metal picrates M+Pic− with M+ = Li+, Na+, K+, Rb+ and Cs+ and divalent metal picrates M2+(Pic−)2 with M2+ = Mg2+, Ca2+, Sr2+, Ba2+, Pb2+, Cd2+, Zn2+ and Co2+ are given. Tentative localisation of the metal cations in the receptors is given. The binding properties towards these cations
have been determined along with stoichiometries of the complexes. 相似文献
10.
T. Hodisan M. Curtui I. Haiduc 《Journal of Radioanalytical and Nuclear Chemistry》1998,238(1-2):129-133
The separation of uranium and thorium from matrices containing various metal ions, was studied. The mobile phase contains
isopropyldithiophosphoric acid (i-PrDTP), as a complexing agent, in order to differentiate the studied species by modifying
their retention. The paper reports the successful separation and the quantitative determination of uranium and thorium in
the presence of Ni2+, Co2+ and Ag+ in the concentration range 2.5–2.5 μg/μl for uranium and 2.5–30 μg/μl for thorium. 相似文献
11.
Saowarux Fuangswasdi Nattawut Kaveevivitchai Thawatchai Tuntulani Paul B. Savage 《Journal of solution chemistry》2008,37(1):45-58
The complexation equilibria of the phenolic diazacrown ether derivatives L1–L11 with transition and heavy metal ions (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ and Pb2+) have been studied in methanol using UV absorption spectrophotometry. A majority of the systems studied formed only ML complexes.
Using a ligand with a different position of the substituents on the phenolic side arms (denoted L7) leads to ML2 formation with most of the metal ions. Every ligand forms very strong ML and ML2 complexes with Pb2+, and, in nearly all cases, only a lower limit could be derived for the stability constant. The stability of the complexes
generally increases as the length of the para-substituents on the phenol groups increases. Among the metal ions tested, Zn2+ and Hg2+ are the least preferred by alkyl and alkoxy derivatives, respectively. 相似文献
12.
Lijun Qian Bin Tong Shu Sun Jianbing Shi Junge Zhi Yuping Dong 《Frontiers of Chemistry in China》2011,6(1):15-20
Transition metal ions (Pb2+, Zn2+, Cd2+, Co2+, Mn2+, Cu2+, Ni2+, Hg2+, Ag+, Fe3+) in water are used to quench emission of 2-(6-oxido-6H-dibenz 〈c,e〉 〈1,2〉 oxaphosphorin-6-yl)-1,4-phenylene-bis(p-pentyloxylbenzoate)s
(MD5) with aggregation-induced emission enhancement (AIEE) in water-acetonitrile (AN) mixture (80:20 by volume). Among all
metal ions, Fe3+ exhibits the highest quenching efficiency on AIEE of MD5 even when the concentration of Fe3+ is lower than 1×10−6 mol/L. The quenching efficiency of Hg2+ is lower than that of Fe3+ at the same concentration, though MD5 is used to detect Hg2+ efficiently, too. To other metal ions, low quenching efficiency has few relations with a wider concentration range. The UV
absorbance spectra show only red shift of absorbance wavelength in the presence of Hg2+ and Fe3+, which indicates a salt-induced Jaggregation. SEM photos reveal larger aggregation and morphological change of nanoparticles
of MD5 in water containing Hg2+ and Fe3+, which reduce the surface area of MD5 emission for further aggregation. The selective quenching effect of transition metal
ions to emission of MD5 has a potential application in chemical sensors of some metal ions. 相似文献
13.
A. V. Shevtsov V. Yu. Petukhova S. A. Kutepov V. V. Kuznetsov N. N. Makhova N. E. Kuz'mina G. G. Aleksandrov 《Russian Chemical Bulletin》2000,49(11):1882-1886
A series of complexes ofN-(2-aminoethyl)diaziridines with transition metal salts (Zn2+, Cd2+, Ni2+, Co2+, Mn2+, or Fe2+) were synthesized. Their structures were established by IR and NMR spectroscopy. The structure of bis[1,2-bis(2-aminoethyl)diaziridine]cadmium(II)
diperehlorate was confirmed by X-ray diffraction analysis.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1910–1914, November, 2000. 相似文献
14.
Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Michel Delamar Florence Babonneau Jacques Livage 《Monatshefte für Chemie / Chemical Monthly》2006,137(3):263-275
Summary. A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula
P–(CH2)3–C11H22O2N5 (where P represents [Si–O]n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional
ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the
uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). 相似文献
15.
Crystalline solvates of synthetic tetraphenylporphyrin and its pyridinie metallocomplexes (Zn2+, Cu2+, Ni2+, Co2+, Mn3+, Fe3+) have been studied by thermogravimetric analysis. A comparative analysis of our thermochemical data and the literature XRD
data was carried out for the pyridine complexes of metallotetraphenylporphyrins. It was found that the energy stability and
structural characteristics of the pyridine complexes of metallotetraphenylporphyrins depended on the nature of the central
metal ion. The pyridine complexes are stabilized by the direct metal porphyrin π-dative macrocycle interaction and the increased
residual positive charge on the central metal ion. The activation energies of thermal destruction of the pyridine complexes
of metallotetraphenylporphyrins vary from 230 kJ·mol−1 to 330 kJ·mol−1, which is suggestive of the high kinetic stability of the complexes. For the molecular complexes under study, the limiting
stage of destruction was found to be the chemical reaction itself, and the kinetic characteristics demonstrated the compensation
effect, indicative of the similar mechanism of thermooxidative destruction of the pyridine complexes of metallotetraphenylporphyrins. 相似文献
16.
Nizam M. El-Ashgar Issa M. El-Nahhal Mohamed M. Chehimi Michel Delamar Florence Babonneau Jacques Livage 《Monatshefte für Chemie / Chemical Monthly》2006,41(1):263-275
A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula
P–(CH2)3–C11H22O2N5 (where P represents [Si–O]n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional
ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the
uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). 相似文献
17.
Emily M. Sible Steven P. Brimmer Julie A. Leary 《Journal of the American Society for Mass Spectrometry》1997,8(1):32-42
Electrospray ionization and tandem mass spectrometry were used in the analysis of metalcoordinated oligosaccharides. Four transition metal ions, Cu2+, Mn2+, Co2+, and Zn2+, and the alkaline earth metal ion Ca2+, were each coordinated to the trimer α1–3, α1–6 mannotriose and the pentamer conserved trimannosyl core (mannotriosyl-chitobiose). Instrumental and concentration ratio optimization studies were carried out to determine the best conditions for producing the [M + Met]2+, [M + MetCl]+, and [M + Met ? H]+ ions (Met = metal dication). These precursors were then subjected to tandem mass spectrometry (MS/MS) analysis and compared. Both the ionic radii and efficacy of ligand coordination were observed as important criteria for producing the precursor ions. Tandem mass spectra for the Cu2+- and Zn2+-coordinated species did not produce significant structural information about either the trimer or the pentamer. Although tandem mass spectra for the Ca2+-, Co2+-, and Mn2+-coordinated trimer were very similar, those of the pentamer were not. MS/MS of the Co2+-coordinated pentamer was the most unique and exhibited very different dissociation pathways. 相似文献
18.
Complexation of heavy metal ions such as Cu2+, Zn2+ and Co2+ by cellulosic fibres cotton, lyocell and viscose was studied in the pH range from pH 7–13. Glycine and sodium D-gluconate complexes were studied. Complex formation in the cellulose matrix depends on ligand, solution pH, complex species
formed and type of cellulosic fibre. Species distribution in solution was calculated using the program SPE and literature
data for formation constants of M2+-glycine and M2+-gluconate complexes. The calculated data permit explanation of the experimental heavy metal uptake in the cellulose matrix.
In presence of GLY lower heavy metal concentrations were observed. Heavy metal complexation decreases with increasing pH between
7 and 11. For Cu2+ and Zn2+ a strong increase in metal binding capacity in the fibres was observed at pH 13 for Cu2+ and pH 11–12 for Zn2+ respectively. Low Zn2+ content is analysed at pH 13 due to zincate formation.
Member of EPNOE, European Network of Excellence “Polysaccharides” . 相似文献
19.
The interactions of polymethacrylopiperidide with Cu2+, Ni2+, Co2+ and Fe3+ ions have been investigated by potentiometric and conductometric titration, ESR and u.v. spectroscopy, viscometry and sedimentation. The average number of ligands coordinating with the central metal ions and the stability constants of polymeric metal complexes were determined. It is assumed that the polymethacrylopiperidide interacts with transition metal ions through the nitrogen atoms. The influence of spatial arrangement of donor atoms on the coordination ability of polyligand is discussed. 相似文献
20.
Lucica Viorica Ababei Angela Kriza Adina Magdalena Musuc Cristian Andronescu Elena Adina Rogozea 《Journal of Thermal Analysis and Calorimetry》2010,101(3):987-996
New complexes of 2-benzoyl-pyridil-isonicotinoylhydrazone (L) with Cu(II), Co(II), Ni(II) and Mn(II), having formula of type
[ML2] SO4·xH2O (M = Cu2+, Co2+, Ni2+, x = 2 and M = Mn2+, x = 3), have been synthesised and characterised. All complexes were characterised on the basis of elemental analyses, IR spectroscopy,
UV–VIS–NIR, EPR, as well as thermal analysis and determination of molar conductivity and magnetic moments. The thermal behaviour
of complexes was studied using thermogravimetry (TG), differential thermal analysis (DTA) and differential scanning calorimetry
(DSC). The structure of L hydrazone was established by X-ray study on single crystal. The ligand works as tridentate NNO,
being coordinated through the azomethine nitrogen, the pyridine nitrogen and carbonylic oxygen. Heats of decomposition, ΔH, associated with the exothermal effects were also determined. 相似文献