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1.
Jayaraman Dessingou 《Tetrahedron letters》2005,46(46):7967-7971
The bis-{N-(2-hydroxynaphthyl-1-methylimine)} anchored 1,3-di-derivative of lower rim p-tert-butyl-calix[4]arene possessing a N2O2, N2O4 or N2O6 binding core was found to be selective for Zn(II) ions even at ?60 ppb by eliciting fluorescence-on behaviour while the other ions, viz., Ti4+, VO2+, Cr3+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Mg2+, Cd2+ and Hg2+ caused no change in the fluorescence. The reaction between 1 and Zn2+ was found to be stoichiometric with the formation of a 1:1 complex; while H+ quenched the fluorescence of the complex, OH− restored it. The studies of the 1:1 isolated complexes of Zn2+, Ni2+ and Cu2+ augmented the results. 相似文献
2.
R. B. Gutsulyak V. N. Britsun Yu. A. Serguchev 《Theoretical and Experimental Chemistry》1995,31(4):200-202
It was shown that the main products of oxidative chlorination of acetylenes by the system K2S2O8-MCln in pyridine are transdichloroalkenes. It was established that the formation of chloro-derivatives from unsaturated hydrocarbons proceeds only in the presence of ions of metals of variable valence (Cu2+, Co2+, Fe3+). A possible reaction scheme is proposed.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 31, No. 4, pp. 243–246, July–August, 1995. 相似文献
3.
A Colorimetric and Fluorimetric Chemodosimeter for Copper Ion Based on the Conversion of Dihydropyrazine to Pyrazine
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Dr. Junbo Li Shao Chen Pian Zhang Zilong Wang Guankui Long Dr. Rakish Ganguly Dr. Yongxin Li Prof. Dr. Qichun Zhang 《化学:亚洲杂志》2016,11(1):136-140
In this research, we successfully synthesized and fully characterized the new compound 5,8,13,16,21,24‐hex‐(triisopropylsilyl)ethynyl)‐6,23‐dihydro‐6,7,14,15,22,23‐hexaza‐trianthrylene ( HHATA , brown color in a mixed solvent of CH2Cl2/CH3CN 1:1, v/v, weakly blue fluorescent), which can be easily oxidized to 5,8,13,16,21,24‐hex‐(triisopropylsilyl)ethynyl)‐6,7,14,15,22,23‐hexazatrianthrylene ( HATA ) (yellow color in CH2Cl2/CH3CN 1:1, v/v), red fluorescent) by Cu2+ ions. This reaction only proceeds efficiently in the presence of Cu2+ ions when compared with other common metal ions such as Fe3+, Co2+, Mn2+, Hg2+, Ni2+, Pb2+, Ag+, Mg2+, Ca2+, K+, Na+, and Li+. Our result suggests that this reaction can be developed as an effective method for the detection of Cu2+ ions. 相似文献
4.
The binding of the transition metal ions VO2+, Fe2+, Fe3+, CO2+, Co3+, Ni2+ and Cu2+ by a poly(iminoethylene) dithiocarbamate copolymer has been investigated by uptake studies and physical measurements (electronic, IR, and ESR spectra and magnetic susceptibility). Metal ions may be bound by both the dithiocarbamato and amino groups of the co-polymer. Binding to nitrogen (in addition to binding to sulphur) increases in the order FE(II)<Ni(II)<Cu(II) and accounted for increasing metal ion uptake by the copolymer in the same order. Factors which determine the relative uptake of the metal ions by the copolymer are discussed. 相似文献
5.
《Journal of mass spectrometry : JMS》2018,53(8):717-724
On‐surface degradation of sildenafil (an adequate substrate as it contains assorted functional groups in its structure) promoted by the Fenton (Fe2+/H2O2) and Fenton‐like (Mn+/H2O2; Mn+ = Fe3+, Co2+, Cu2+, Mn2+) systems was investigated by using paper spray ionization mass spectrometry (PS‐MS). The performance of each system was compared by measuring the ratio between the relative intensities of the ions of m/z 475 (protonated sildenafil) and m/z 235 (protonated lidocaine, used as a convenient internal standard and added to the paper just before the PS‐MS analyzes). The results indicated the following order in the rates of such reactions: Fe2+/H2O2 ≫ H2O2 ≫ Cu2+/H2O2 > Mn+/H2O2 (Mn+ = Fe3+, Co2+, Mn2+) ~ Mn+ (Mn+ = Fe2+, Fe3+, Co2+, Cu2+, Mn2). The superior capability of Fe2+/H2O2 in causing the degradation of sildenafil indicates that Fe2+ efficiently decomposes H2O2 to yield hydroxyl radicals, quite reactive species that cause the substrate oxidation. The results also indicate that H2O2 can spontaneously decompose likely to yield hydroxyl radicals, although in a much smaller extension than the Fenton system. This effect, however, is strongly inhibited by the presence of the other cations, ie, Fe3+, Co2+, Cu2+, and Mn2+. A unique oxidation by‐product was detected in the reaction between Fe2+/H2O2 with sildenafil, and a possible structure for it was proposed based on the MS/MS data. The on‐surface reaction of other substrates (trimethoprim and tamoxifen) with the Fenton system was also investigated. In conclusion, PS‐MS shows to be a convenient platform to promptly monitor on‐surface oxidation reactions. 相似文献
6.
A. V. Levanov I. V. Kuskov K. B. Koiaidarova E. I. Antipenko V. V. Lunin 《Kinetics and Catalysis》2006,47(5):682-685
The effect of sulfuric acid concentration on Cl2 evolution in the reaction between O3 and Cl? has been investigated. The catalytic effects of metal ions in this reaction have been studied as a function of solution acidity. The chlorine evolution rate increases markedly with increasing acid concentration. At acid concentrations below 4 mol/l, the most effective catalyst is Co2+. The catalytic activities of Fe3+ and Cu2+ peak at $C_{H_2 SO_4 } $ = 4.8 mol/l. In passing to highly acidic solutions ( $C_{H_2 SO_4 } $ > 5 mol/l), the catalytic activity of the metal ions decreases, but the chlorine evolution rate remains high owing to the high acidity. Kinetics of VO2+ oxidation with ozone in acid media have been studied, and the ozone solubility in aqueous sulfuric acid has been measured. 相似文献
7.
Mordechai L. Kremer 《国际化学动力学杂志》2006,38(12):725-736
The promotion of the Fenton reaction by Cu2+ ions has been investigated using a wide range of [Cu2+]. Both the disappearance of Fe2+ and the evolution of O2 were followed as a function of time by quenching the reaction mixture with o‐phenanthroline or with excess Fe2 + ions, respectively. Two series of experiments were performed. In one series [H2O2] was 5 × 10−4 mol dm−3, and in the other [H2O2] was reduced to 5 × 10−5 mol dm −3. By stopping the reaction with excess Fe2+ ions, significant differences in the measured absorbance in the two series were observed. In the higher [H2O2] range, the absorbance decreased monotonically in time, due to O2 formation during the reaction. In the lower range, an initial transient rise of the absorbance was observed, indicating the formation of spectroscopically distinct intermediates in the system. A mechanism involving the intermediates FeOCu4+ and FeOCu5+ has been set up. Rate constants of the mechanism have been determined. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 725–736, 2006 相似文献
8.
Kobasa I. M. Mazurkevich Ya. S. Zozulya N. I. 《Theoretical and Experimental Chemistry》2003,39(5):316-321
We have established the high catalytic activity of TiO2, modified by Pd2+, Cu2+, Fe3+, and Co2+ ions, in reduction of Cu2+ ions by formaldehyde in solution. We propose a likely scheme for the electronic processes that occur, including injection of electrons from the reducing agent into the conduction band and formation of metallic nanoparticles on the surface that effectively catalyze deposition of metallic copper. 相似文献
9.
Toshio Takayanagi Yuya Inaba Hiroyuki Kanzaki Yasutaka Jyoichi Shoji Motomizu 《Talanta》2009,79(4):1089-37
Catalytic effect of metal ions on luminol chemiluminescence (CL) was investigated by sequential injection analysis (SIA). The SIA system was set up with two solenoid micropumps, an eight-port selection valve, and a photosensor module with a fountain-type chemiluminescence cell. The SIA system was controlled and the CL signals were collected by a LabVIEW program. Aqueous solutions of luminol, H2O2, and a sample solution containing metal ion were sequentially aspirated to the holding coil, and the zones were immediately propelled to the detection cell. After optimizing the parameters using 1 × 10−5 M Fe3+ solution, catalytic effect of some metal species was compared. Among 16 metal species examined, relatively strong CL responses were obtained with Fe3+, Fe2+, VO2+, VO3−, MnO4−, Co2+, and Cu2+. The limits of detection by the present SIA system were comparable to FIA systems. Permanganate ion showed the highest CL sensitivity among the metal species examined; the calibration graph for MnO4− was linear at the concentration level of 10−8 M and the limit of detection for MnO4− was 4.0 × 10−10 M (S/N = 3). 相似文献
10.
Salman M. Saadeh Nizam M. El‐Ashgar Issa M. El‐Nahhal Mohamed M. Chehimi Jocelyne Maquet Florence Babonneau 《应用有机金属化学》2005,19(6):759-767
A porous, solid insoluble polysiloxane‐immobilized ligand system bearing pyrogallol active sites of the general formula P? (CH2)3? NH(CH2)3OC6H3(OH)2 (where P represents [Si? O]n siloxane network) has been prepared by the reaction of 3‐aminopropylpolysiloxane with 1,3‐dibromopropane followed by the reaction with pyrogallol. 13C CP‐MAS NMR and X‐ray photoelectron spectroscopy confirmed that the pyrogallol is chemically bonded to the siloxane backbone. Thermal analysis showed that the ligand system is stable under nitrogen at relatively high temperature. The polysiloxane–pyrogallol ligand system exhibits high potential for the uptake of the metal ions (Fe3+, Co2+, Ni2+ and Cu2+). Complexation of the pyrogallol ligand system for the metal ions at the optimum conditions was found to be in the order Fe3+ > Cu2+ > Ni2+ > Co2+. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
11.
Nizam M. El‐Ashgar Mohamed M. Chehimi Carole Connan Florence Babonneau Jacques Livage 《Journal of Dispersion Science and Technology》2013,34(3):445-453
A new porous solid macrocyclic 1,4,7,10,14,17,20‐heptaazadocosane‐3,21‐dione polysiloxane ligand system of the general formula P‐(CH2)3‐C15H32O2N5, (where P represents [Si‐O]n siloxane network) has been prepared by the reaction of immobilized iminobis(N‐diethylenediamineacetamide)polysiloxane with 1,3 dibromopropane. The new macrocyclic polysiloxane ligand system exhibits high potential for the uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+). Complexation with copper ions exhibits a high selectivity in which two copper ions were involved per one macrocyclic ligand group. 相似文献
12.
The kinetics of H2O2 decomposition have been investigated using ZrO2 supported with transition metal ions including CuII, AgI, HgII, CoII, MnII, NiII and FeIII. At pH = 6.8, the reaction rate exhibits a first order dependence on the initial H2O2 concentration at low concentrations. The order of activity of the different catalysts is strongly dependent on the [H2O2]0 used. The reaction proceed via the formation of the peroxo-intermediate which has an inhibiting effect on the reaction rate. The rate increases with increasing pH, and attains a limiting rate at higher pH's. A reaction mechanism is proposed involving liberation of HO2 radicals from the peroxo-intermediate as the rate-determining step. 相似文献
13.
《Journal of separation science》2017,40(3):789-797
A common drawback of paper‐based separation devices is their poor detection limit. In this study, we combined field‐amplified sample stacking with moving reaction boundary electrophoresis on a paper chip with six array channels for the parallel separation and concentration of multiple samples. With a new hyphenated technique, the brown I2 from the Fe3+/I− oxidation–reduction reaction emerged near the boundary between the dilute ethylene diamine tetraacetic acid and potassium iodide and highly concentrated KCl solutions. For the separation and concentration of three components, Cr3+, Cu2+, and Fe3+, the Fe3+ detection limit was improved at least 266‐fold by comparing the hyphenated technique with moving reaction boundary electrophoresis. The detection limit of Fe3+ was found to be as low as 0.34 ng (20 μM) on the paper chip. We also demonstrated the analysis of a real sample of four metal ions, with detection limits as follows: 0.16 μg Cr3+, 1.5 μg Ni2+, 0.64 μg Cu2+, and 1.5 μg Co2+. The synergy of field‐amplified sample stacking and moving reaction boundary electrophoresis in the micron paper‐based array channels dramatically improved the detection limit and throughput of paper‐based electrophoresis. 相似文献
14.
Yin Li Zsolt Csók Péter Szuroczki László Kollár László Kiss Sándor Kunsági-Máté 《Analytica chimica acta》2013
A novel ‘three-level’ deepened cavitand featuring a significantly sizable portal has been synthesized and its interaction with some transition metal ions has been investigated in THF/H2O binary solvent using fluorescence quenching technique. The results suggest that among the used transition metal ions including Ag+, Cd2+, Cu2+, Fe3+, Cr3+, Hg2+, La3+, Mn2+, Ni2+, Zn2+ and Co2+, only Fe3+ and Cu2+ show good quenching ability. In order to interpret the quenching mechanism, the Stern–Volmer kinetics, and the presence of both the dynamic and static quenching have been discussed. It was found that the simultaneous presence of the sphere-of-action static quenching and dynamic quenching model agrees very well with the experimental results. The limits of detection for Fe3+ and Cu2+ were found to be 2.1 × 10−6 mol L−1 (3σ) and 3.6 × 10−6 mol L−1 (3σ), respectively. Cations with potential interference, such as K+, Na+, Mg2+, Ca2+, Co2+, La3+ and Mn2+ do not have significant effects on the determinations of Fe3+ and Cu2+. This cavitand can be potentially applied as optical sensor for the detection of Fe3+ and Cu2+. 相似文献
15.
Chelation ion-exchange properties of copolymers prepared from salicylic acid, urea and formaldehyde by condensation in presence
of acid catalyst were studied for Cu2+, Fe3+, UO2+, Mn2+,Zn2+ and Co2+ ions. A batch equilibration method was adopted to study the selectivity of metal ion uptake. This method involved the measurement
of distribution of a given metal between the copolymer sample and a solution containing the metal ions. The study was carried
out over a wide pH range and in media of various ionic strengths. The copolymer showed a higher selectivity for UO2
2+, Cu2+ and Fe3+ ions than Mn2+, Co2+ and Zn2+ ions. 相似文献
16.
Vadithala Ramakrishna Rao Korandla Goverdhan Reddy Utukuri Venkata Seshaiah Vuppalapati Jayathyagaraju 《Transition Metal Chemistry》1993,18(3):258-261
Summary
N-salicylidene anthranilamide (H2SAA) and its CrIII, MnII, FeIII, CoII, NiII and CuII complexes were prepared and characterized by physicochemical and spectroscopic data. H2SAA enolizes to give a dibasic ONO donor set in the divalent metal complexes. It also binds to the trivalent metal ions in a nonenolized form using a monobasic ONN donor set. CoII is oxidized to CoIII during complexation. Octahedral geometries are proposed for CrIII, MnII, FeIII and CoIII complexes, while square planar geometries are suggested for the NiII and CuII complexes. Phenoxide bridging in the CrIII and FeIII complexes and enoxide bridging in the NiII and CuII complexes is proposed. 相似文献
17.
The reagent pentacyanoamminoferrate (PCAF) in its aqueous reactions with some common cations and anions produces colored species in solution. It has been observed that the reactions of Fe3+, Fe2+, Co2+, VO2+, Mo6+, S2O32−, and NO2− are sensitive enough to permit their colorimetric determinations. In addition, the reagent has been found useful in the simultaneous trace analysis of Fe3+ and VO2+ present in the same solution.A comparative study has been made of the reactions of PCAF and the other unsubstituted cyanoferrates(II) and (III). 相似文献
18.
The oxyfluoride garnets of formula Y3Fe5?xMxO12?xFx and Gd3Fe5?xMxO12?xFx (M = 3d transition element) result from partial substitution of O2? by F? in Y3Fe5O12 and Gd3Fe5O12 oxides. The cationic charge compensation is obtained by replacing the Fe3+ ions by divalent ions as Mn2+, Co2+, Ni2+, Cu2+ or Zn2+ ions. The site occupied by some of these ions (Mn2+, Ni2+, Zn2+) is determined by magnetic or Mössbauer measurements. 相似文献
19.
Atanu Mitra 《Tetrahedron letters》2009,50(7):776-1321
A new glucose-based C2-derivatized colorimetric chemo-sensor (L1) has been synthesized by a one-step condensation of glucosamine and 2-hydroxy-1-naphthaldehyde for the recognition of transition metal ions. Among the eleven metal ions studied, viz., Mg2+, Ca2+, Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+ and Hg2+, L1 results in visual colour change only in the presence of Fe2+, Fe3+and Cu2+ in methanol. However, in an aqueous HEPES buffer (pH 7.2) it is only the Fe3+ that gives a distinct visual colour change even in the presence of other metal ions, up to a concentration of 280 ppb. The changes have been explained based on the complex formed, and the composition has been determined to be 2:1 between L1 and Fe3+ based on Job’s plot as well as ESI MS. The structure of the proposed complex has been derived based on HF/6-31G calculations. 相似文献
20.
Jingfu Liu Jun Guo Benliang Zhao Guiying Xu Mingxiu Li 《Transition Metal Chemistry》1993,18(2):205-208
Summary A novel polyanionic ligand (LaAs4W40O140)25- and its derivatives (LaAs4W40O140M2)n- (M = Mn2+, Fe2+, Fe3+, Cr3+, Co2+, Ni2+, Cu2+ or Zn2+) have been prepared and characterized by elemental analyses, i.r., u.v.-vis. and emission spectra, 183W-n.m.r. and polarography. There is evidence that lanthanide occupies the central S1 site, whereas the transition metal cations occupy the S2 site, in the complexes. 相似文献