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151.
152.
Altu? Mert Sevim Rustam Hojiyev Ahmet Gül Mehmet Sabri ?elik 《Monatshefte für Chemie / Chemical Monthly》2012,102(1):385-400
Abstract
Adsorption of an octacationic tetrapyrrole, octakis(2-trimethylammoniumethylsulfanyl)porphyrazinatocobalt octaiodide (QCoPz), from aqueous solutions on to negatively charged bentonite was investigated. Effects of temperature, dye concentration, solid concentration, and contact time on adsorption were determined. Zeta potential and ion-release measurements were also used as supporting experiments. Experimental data were analyzed using four adsorption kinetic models; a pseudo second-order kinetic model resulted in better correlation with experimental results than the others. Experimental equilibrium data were analyzed by non-linear regression using five adsorption isotherm models with two, three, or four terms. Free energies, enthalpies, and entropies for the adsorption process were determined. The results indicated that adsorption of QCoPz on bentonite was exothermic and spontaneous in nature. FT-IR spectroscopy of the composite and its desorptive behavior were also investigated to identify the mechanism of adsorption. The novel QCoPz–bentonite composites obtained are likely to be used in “green chemistry” and in a wide range of optical and/or catalytic applications, especially those crucially important in the petroleum and pulp/paper industries for waste water cleaning (destruction of mercaptans, sulfides, phenol, and halogenated aromatics, etc.) and removal of bad odor. 相似文献153.
154.
Guzel Ziyatdinova Ekaterina Kozlova Herman Budnikov Rustam Davletshin 《Electroanalysis》2019,31(2):222-230
Novel voltammetric approach for the selective determination of total capsaicinoids has been developed using glassy carbon electrode modified with multi‐walled carbon nanotubes and poly(gallic acid) (PGA/MWNT/GCE). The modified electrode provides significant improvements in the capsaicinoids voltammetric characteristics in comparison to GCE and MWNT/GCE. The electrooxidation of capsaicinoids is irreversible adsorption‐controlled process with the anodic transfer coefficient of 0.49–0.53 and heterogeneous electron transfer rate constant of 1300–2400 s?1. The analytical ranges of 0.010–1.0 and 1.0–50 μM for capsaicin, 0.025–0.75 and 0.75–75 μM for dihydrocapsaicin and 0.025–5.0 and 5.0–75 μM for nonivamide with the detection limits of 2.9, 5.9 and 6.1 nM, respectively, have been obtained using differential pulse voltammetry (DPV). The selectivity of the capsaicinoids quantification in the presence of ascorbic acid, α‐tocopherol and carotenoids is shown. The method has been tested on the samples of red hot pepper spices and Capsicum annuum L. tinctures. The results correspond to the chromatographic data. 相似文献
155.
156.
157.
158.
Alphia R. Gataulina Damir A. Safin Timur R. Gimadiev Marina V. Pinus 《Transition Metal Chemistry》2008,33(7):921-924
Reaction of the potassium salts of podand-containing bis(dithiophosphonate)s [PhO(4-C6H4)P(S)(SH)OCH2CH2]2O (H
2
L) with Co(II), Ni(II) and Cd(II) in aqueous EtOH leads to complexes of formulae M2(L-S,S′)2. The structural formulae of the compounds were deduced by physico-chemical and spectroscopic methods. It was established
that complex Ni
2
L
2
recognizes CH2Cl2. 相似文献
159.
Prof. Dr. Alexey A. Goryunkov Dr. Nail L. Asfandiarov Rustam G. Rakhmeev Angelina V. Markova Dr. Stanislav A. Pshenichnyuk Alexey V. Rybalchenko Dr. Natalia S. Lukonina Prof. Dr. Ilya N. Ioffe 《Chemphyschem》2022,23(10):e202200038
Gas phase molecules of hexachlorobenzene (C6Cl6) were investigated by means of dissociative electron attachment spectroscopy (DEAS). Three channels of molecular negative ions decay have been identified: abstraction of Cl− and Cl2− as well as electron detachment (τa∼250 μs at 343 K). All three channels exhibit temperature dependence. The adiabatic electron affinity estimated using a simple but typically accurate Arrhenius model (EAa=1.6–1.9 eV) turns out to be much higher than the quantum-chemical predictions (EAa=0.9–1.0 eV). We discuss the possible reasons behind the observed discrepancy. 相似文献
160.
F. D. Sokolov D. A. Safin N. G. Zabirov P. V. Zotov R. A. Cherkasov 《Russian Journal of General Chemistry》2005,75(12):1919-1926
The reaction of potassium salts of N-thiocarbamoylamidophosphates RC(S)NHP(O)(OPr-i)2X [X = PhNH, p-MeOPhNH, p-BrPhNH, i-PrNH, t-BuNH, Et2N, C5H10N, OC4H8N, C6H11NH] with Zn(II) cation gives complexes of the composition Zn(L-O,S)2. The Cd(II) complexes could not be isolated under analogous conditions because of their hydrolytic lability. The reaction of thioureas (X = PhNH, p-MeOPhNH) with Cd(II) acetate in DMF provides stable solvato complexes of the composition Cd(DMF)2L2. The structure of the resulting compounds was studied by means of IR, 1H, and 31P NMR spectroscopy and EI and ESI mass spectrometry. 相似文献