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121.
LiDong Wang Yi Zhao QiangWei Li ZhouYan Chen SongTao Liu YongLiang Ma JiMing Hao 《中国科学B辑(英文版)》2009,52(1):109-116
Oxidation of sulfite is an important process in wet flue gas desulfurization. Using highly purified water or distilled water
as a reaction medium and a transparent or an opaque intermittent reaction apparatus, the intrinsic oxidation kinetics of sulfite
catalyzed by peracetic acid was investigated under four different conditions. The reaction order of the reagents and the activation
energy were obtained. The results indicate that water quality and light have no obvious effects on the reaction order and
activation energy, but have an influence on the reaction rate constant. The mechanism of the intrinsic reaction is proposed.
The results derived with this mechanism are in good agreement with the experimental results.
Supported by the National Basic Research Program of China (Grant No. JK00020), the Doctor Research Fund from North China Electric
Power University (Grant No. 200612008), and the National High Technology Research and Development Program of China (Grant
No. 2007AA061703) 相似文献
122.
It is shown that gold does not virtually dissolve in alkaline (pH 12.5) solutions containing either thiocarbamide or sodium sulfite. Gold dissolves in alkaline solutions simultaneously containing thiocarbamide (0.1 M) and sodium sulfite (0.5 M). The gold dissolution rate increases with the increase in the contents of thiocarbamide and sodium sulfite. The methods of microbalance and voltammetry are used in studying the mechanism of gold dissolution in a solution containing 0.5 M sodium sulfite, 0.1 M thiocarbamide, and 0.03 M KOH. The found relationships are explained based on the assumption that the gold dissolution in alkaline sulfite-thiocarbamide electrolytes affords gold sulfite complexes. 相似文献
123.
124.
Abstract The oxidation of Cu(II)/tetraglycine complex in borate buffer (pH=9.2) in aqueous medium, by dissolved oxygen is strongly accelerated by S(IV). The reaction is adequate for S(IV) determination as the concentration of (Cu(H-3G4)]? formed is proportional to SO32- concentration. The [Cu(H-3G4)]? presents a maximum absorbance at 365 nm (? = 7400 mol?1.L.cm?1) and it was followed spectrophotometrically by flow injection analysis procedure. The detection limit was 7×10?6 mol.L?1 and the linear regression showed a standard deviation of 0.02% (n=5). Kinetics studies showed the catalytic effect of some transition metal ions, “which can be present in environmental samples, in the oxidation of S(IV). The pseudo-first-order rate constants were determined in the presence of formaldehyde. 相似文献
125.
Radu Silaghi‐Dumitrescu Sergei V. Makarov 《International journal of quantum chemistry》2012,112(3):900-908
Siroheme‐containing sulfite reductases (SiR) catalyze the six‐electron reduction of sulfite to sulfide via a mechanism involving sulfite binding at the heme iron. The exact sequence in which the required electrons and protons are delivered to the heme‐bound sulfite has received little attention to date. Here, a detailed account is given of these steps, based on density functional theory, thus providing data for the first attempt to draw a detailed picture of sulfite reduction in SiR by theoretical methods. Parallels are shown with reduction of other small molecules at heme centers: dioxygen (including generation of sulfide high‐valent iron centers akin to hemoproteins Compounds I and II), nitrite (including linkage isomerism akin to the nitro/nitrito known for nitrite reducing proteins), or nitric oxide. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
126.
《Journal of Coordination Chemistry》2012,65(17):2782-2791
The aim of this work is to study four types of modification of a glassy carbon electrode by Fe(III)-tetrakis(p-tetraaminophenyl)porphyrin and determine the influence of the method of immobilization of the complex on glassy carbon in electrocatalytic properties for the sulfite and hydrogensulfite oxidation in ethanol–water. The first modification was deposition of a drop of solution containing the porphyrin on a glassy carbon electrode and evaporation of the solvent (dry-drop method). The second method was immersion of the electrode at 54°C in a solution of dimethylformamide containing the porphyrin for 2 h. The third method consisted of the same heating treatment but after formation of a chemical bond of 4-aminopyridine on the glassy carbon surface, which acts as an axial ligand for the first layer of porphyrin. The fourth method involves electropolymerization of the porphyrin on the electrode surface. Important differences in stability, the potential where the oxidation wave begins and selectivity of the electrode to sulfite or hydrogensulfite were observed. The behavior of the polymer-modified electrode is different in water compared to ethanol–water. 相似文献
127.
HUANG Wei-Yuan WU Fan-Hong HUANG Bing-NanShanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai China 《中国化学》1994,12(6):549-551
Polyfluoroalkyl iodides, such as Cl(CF2)nI(n=4, 6, 8, 1b-1d) and F(CF2)nI (n=6, 8,1e-1f) reacted with sodium sulfite in neutral aqueous DMF solution to give the corresponding sulfinates Cl(CF2)nSO2Na (n=4, 6, 8, 2b-2d) and F(CF2)nSO2Na (n=6, 8, 2e-2f) in moderate yields. I(CF2)2O(CF2)2SO2F ( la ) reacted under the same condition to give 3-oxa-octafluoropentane-1,5-disulfinates (2a). 相似文献
128.
Kryukov A. I. Zin'chuk N. N. Korzhak A. V. Kuchmii S. Ya. 《Theoretical and Experimental Chemistry》2003,39(1):9-14
The formation of nanoparticles of metallic silver in the reduction of Ag+ ions catalyzed by colloidal Ag2S was investigated. It was established that the position of the surface plasmon resonance bands of the Ag nanoparticles is affected by the concentration of the catalyst, its particle size and the amount of particles with the same size, the stabilization conditions, the concentration of Ag+ ions, and the temperature at which the process is conducted. An explanation for the spectral changes that occur is proposed. 相似文献
129.
L. Vikram D. S. Shanthakumar R. Ragul B. N. Sivasankar 《Journal of Thermal Analysis and Calorimetry》2007,89(2):521-524
Some new hydrazinium transition metal sulfite dihydrate complexes of the formula (N2H5)2M(SO3)2(H2O)2 where M=Fe, Co, Ni, Cu and Zn have been prepared and characterized by hydrazine and metal analyses, magnetic studies, electronic
and infrared spectra and thermal analysis. The magnetic studies coupled with electronic spectra of iron, cobalt, nickel and
copper complexes indicate their high spin octahedral nature. However the zinc complex is diamagnetic and show only the charge
transfer transition. The infrared spectra shows that both the hydrazinium ions are coordinated to the metal ions, the sulfite
ions are present as bidentate ligand.
The simultaneous TG-DTA of these complexes were investigated in air and nitrogen atmospheres. In air, cobalt, nickel and zinc
complexes give respective metal sulfate as the final residue while iron and copper complexes give the mixture of respective
metal oxide and sulfate as the decomposition product. In nitrogen atmosphere respective metal sulfites are formed as the end
residue. 相似文献
130.
1,2-O-Sulfinyl derivatives of d- and l-arabinose, d-xylose and d-glucose treated by potassium anion of diethyl oxoglutarate gave, exclusively, the corresponding O-glycosides in 92-97% yields. 相似文献