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141.
Novel sulfate ion-selective polymeric membrane electrode based on a derivative of pyrilium perchlorate 总被引:1,自引:0,他引:1
Ganjali MR Naji L Poursaberi T Taghizadeh M Pirelahi H Yousefi M Yeganeh-Faal A Shamsipur M 《Talanta》2002,58(2):359-366
A sulfate ion-selective PVC membrane sensor based on 4-(4-bromophenyl)-2,6-diphenylpyrilium perchlorate (BDPP) as a novel sensing material is successfully developed. The electrode shows a good selectivity for sulfate ion with respect to common organic and inorganic anions. The sensor exhibits a good linear response with slope of -28.9+/-0.5 mV per decade over the concentration range of 1.0x10(-6)-1.0x10(-2) M, and a detection limit of 8.0x10(-7) M of SO(4)(2-) ions. The electrode response is independent of pH in the range of 4.0-9.0. The proposed sensor was applied as an indicator electrode in potentiometric titration of sulfate and barium ions, and to the determination of zinc in zinc sulfate tablets. 相似文献
142.
Mojtaba Shamsipur Morteza Hosseini Mohammad Mehdi Eskandari Mir Fazlollah Mousavi 《Analytica chimica acta》2003,486(1):93-99
New polymeric membrane (PME) and coated graphite (CGE) samarium(III)-selective electrodes were prepared based on isopropyl 2-[(isopropoxycarbothioyl) disulfanyl]ethanethioate as a suitable neutral ionophore. The electrodes exhibit Nernstian slopes for Sm3+ ions over wide concentration ranges (1.0×10−5 to 1.0×10−1 M for PME and 1.0×10−6 to 1.0×10−1 M for CGE). The PME and CGE have limits of detection of 3.1×10−6 and 5.0×10−7 M, respectively, and response times of about 20 s. The potentiometric responses are independent of the pH of the test solution in the pH range 4.0-7.0. The proposed electrodes revealed good selectivities over a wide variety of other cations including alkali, alkaline earth, transition and heavy metal ions. The electrodes were successfully applied to the recovery of Sm3+ ion from tap water samples and also, as an indicator electrode, in potentiometric titration of samarium(III) ions. 相似文献
143.
Summary A simple and rapid kinetic method for the determination of traces of molybdenum (0.1–4.0 g/ml) based on its catalytic effect on the reduction of safranine by hydrazine dihydrochloride is reported. The reaction is monitored spectrophotometrically by measuring the decreasing absorbance of safranine at 520 nm by the fixed time method. The method is sensitive, precise and free from interferences from many anions and cations. The experimental limit of detection is 100 ng/ml and the relative standard deviation for 1.0 g/ml Mo(VI) is 1.56%. The procedure was successfully applied to the determination of molybdenum in a steel alloy. 相似文献
144.
Ali Jabbari Masoumeh Hasani Mojtaba Shamsipur 《Journal of inclusion phenomena and macrocyclic chemistry》1993,15(4):329-340
The complexation reactions between Tl+ and Ag+ ions and several crown ethers have been studied conductometrically in acetonitrile, acetone and dimethylformamide solutions at 25°C. The stability constants of the resulting 1:1 complexes were determined, and found to decrease in the order DA18C6>DC18C6>DB30C10>18C6>DB21C7>DB24C8>DB18C6>B15C5 >12C4, in the case of Tl+ complexes, and in the order DA18C6>DC18C6>18C6>DB18C6 >DB24C8>DB30C10B15C5>DB21C7 for Ag+ complexes. There is an inverse relationship between the stabilities of the complexes and the Gutamnn donicity of the solvents. The influence of a number of atoms in the macrocycle and of substituents in the polyether ring on the stability of the complexes is discussed. 相似文献
145.
Mehdi Taghdiri Mohammad Kazem Rofouei Mojtaba Shamsipur 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(1-2):181-186
The complexation reactions between dibenzo-24-crown-8 (DB24C8) and K+, Rb+, Cs+ and Tl+ ions were studied conductometrically in different acetonitrile–nitromethane mixtures at various temperatures. The formation
constants of the resulting 1:1 complexes were calculated from the computer fitting of the molar conductance–mole ratio data
at different temperatures. At 25 °C and in all solvent mixtures used, the stability of the resulting complexes varied in the
order Tl+ > K+ > Rb+ > Cs+. The enthalpy and entropy changes of the complexation reactions were evaluated from the temperature dependence of formation
constants. It was found that the stability of the resulting complexes increased with increasing nitromethane in the solvent
mixture. The TΔS° vs. ΔH° plot of all thermodynamic data obtained shows a fairly good linear correlation indicating the existence
of enthalpy–entropy compensation in the complexation reactions. 相似文献
146.
A conductance study of the interaction between cobalt, nickel, copper, zinc, cadmium, and lead ions with 1,10-diaza-18-crown-6 in different acetonitrile-dimethylsulfoxide mixtures has been carried out at various temperatures. The formation constants of the resulting 11 complexes were determined from the molar conductance-mole ratio data and found to vary in the order Zn2+2+2+2+2+2+. The enthalpy and entropy of complexation reactions were determined from the temperature dependence of the formation constants. A linear relationship is observed between the log Kf of different complexes and mole fraction of acetonitrile in the solvent mixtures. The TS vs. H plot of all thermodynamic data obtained shows a fairly good linear correlation indicating the existence of an enthalpy-entropy compensation in the complexation reactions. 相似文献
147.
Ali Sharifi Mojtaba Mirzaei M. Reza Naimi-Jamal 《Monatshefte für Chemie / Chemical Monthly》2006,137(2):213-217
Summary. A variety of 1,3-diyne compounds are prepared in a solvent-free reaction on KF/alumina in the presence of catalytic amounts
of Cu(OAc)2·H2O with up to 96% yields at room temperature. 相似文献
148.
Hossein Aghabozorg Farshid Ramezanipour Parvaneh D. Kheirollahi Ali A. Saei Ardeshir Shokrollahi Mojtaba Shamsipur Faranak Manteghi Janet Soleimannejad Mahboubeh A. Sharif 《无机化学与普通化学杂志》2006,632(1):147-154
Three new complexes of group thirteen metals, gallium(III), indium(III), and thallium(III) with proton transfer compounds, obtained from 2,6‐pyridinedicarboxylic acid (dipicolinic acid), were synthesized and characterized using elemental analysis, IR, 1H and 13C NMR spectroscopy and single crystal X‐ray diffraction. The gallium(III) and indium(III) complexes were prepared using (pydaH2)(pydc) (pyda = 2,6‐pyridinediamine, pydcH2 = dipicolinic acid) and thallium(III) complex was obtained from (creatH)(pydcH) (creat = creatinine). The chemical formulae and space groups of the complexes are (pydaH)[Ga(pydc)2] · 3.25H2O · CH3OH, ( 1 ), [In(pydc)(pydcH)(H2O)2] · 5H2O, Pna21 ( 2 ) and [Tl2(pydcH)3(pydc)(H2O)2], ( 3 ). Non‐covalent interactions such as ion‐pairing, hydrogen bonding and π‐π stacking are discussed. The complexation reactions of pyda, pydc, and pyda + pydc with In3+ and Ga3+ ions in aqueous solution were investigated by potentiometric pH titrations, and the equilibrium constants for all major complexes formed are described. 相似文献
149.
Mojtaba Shamsipur Jahanbakhsh Ghasemi 《Journal of inclusion phenomena and macrocyclic chemistry》1994,20(2):157-171
A conductance study of the interaction between Co2+, Ni2+, Cu2+, Cd2+, Zn2+ and Pb2+ ions with cryptands C211, C221 and C222 in different acetonitrile-dimethylsulfoxide mixtures has been carried out at various temperatures. The formation constants of the resulting metal cryptates were determined from the molar conductance-mole ratio data. It was found that the stability of Co2+, Ni2+, Cu2+ and Zn2+ cryptates vary in the order C211>C221>C222, while for Cd2+ cryptates the stability order is C221>C222>C211. A linear relationship is observed between logK
f
of different metal cryptates and the mole fraction of acetonitrile in the solvent mixture. The enthalpy and entropy of cryptate formation reactions were determined from the temperature dependence of the formation constants. The enthalpy and entropy changes are quite sensitive to the solvent composition and the resultingTS
0–H
0 plot shows a fairly good linear correlation, indicating the existence of an entropy-enthalpy compensation in the cryptate formation reactions.
Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82181 (30 pages). 相似文献
150.
Ali Sharifi Rahman Hosseinzadeh Mojtaba Mirzaei 《Monatshefte für Chemie / Chemical Monthly》2002,133(3):329-332
Summary. The palladium-catalyzed coupling reaction of aryl bromides with various amines under microwave irradiation was studied using
PdCl2 [P(o-tolyl)3]2 which gave various aryl amines in good yields. The reactions were carried out under normal atmospheric conditions.
Received September 3, 2001. Accepted October 10, 2001 相似文献