UV-visible spectroscopic investigations of the modified claus reaction on NaX zeolite catalysts
作者:H KARGE
DOI:10.1016/0021-9517(88)90208-4
日期:1988.2
Interaction of SO2 and H2S, i.e., the Clausreaction, on faujasite-type zeolitecatalysts was studied by combined UV-visible and IR spectroscopy. Reactivity of HSO−3, formed by chemisorption of SO2, and HS−, formed by dissociative adsorption of H2S, was confirmed. An effect of thermal treatment after preadsorption of H2S on the kinetics of interaction with subsequently admitted SO2 was observed. S2O2−4
Detailed Mechanistic Studies into the Reactivities of Thiourea and Substituted Thiourea Oxoacids: Decompositions and Hydrolyses of Dioxides in Basic Media
作者:Merfat M. Aslabban、Risikat Ajibola Adigun、William DeBenedetti、Wilbes Mbiya、Morgen Mhike、Kayode Morakinyo、Adenike Otoikhian、Tinashe Ruwona、Reuben H. Simoyi
DOI:10.1021/jp5038156
日期:2014.11.26
from HS– to SO42–. Decomposition products were dependent on concentrations of molecular oxygen. Solutions open to the atmosphere, with availability to excess oxygen, gave the urea analogue of the thiourea and sulfate, while in limited oxygen conditions hydrogen sulfite and other mixed oxidation states sulfur oxoanions are obtained. DMAIMSA has the longest C–S bond at 0.188 nm and was the most reactive
Cathodic Reduction of Bisulfite and Sulfur Dioxide in Aqueous Solutions on Copper Electrodes: An Electrochemical ESR Study
作者:Ian Streeter、Andrew J. Wain、James Davis、Richard G. Compton
DOI:10.1021/jp058119n
日期:2005.10.1
The electrochemical reduction of aqueous solutions of sulfite under acidic conditions on copper electrodes is reported, and a mechanism is proposed. Cyclic voltammetry at a copper disk suggests the operation of two reduction processes, the dominant process depending on solution pH. At very low pH (0-2), sulfurdioxide is reduced in a two-electron, two-proton reaction, but at higher pH (2-5), bisulfite
An algorithm for the design of propagating acidity fronts
作者:Lajos Szirovicza、Istvan Nagypal、Endre Boga
DOI:10.1021/ja00190a016
日期:1989.4
expected to be autocatalytic and to manifest propagatingacidityfronts. The conditions of proton production in redox reactions are established and verified experimentally by the reaction of S 2 O 3 2− , S 4 O 6 2− , S 2 O 4 2− , SO 3 2− , S 2 O 6 2− , and N 2 H 5 + with BrO 3 − , IO 3 − , ClO 3 − , ClO 2 , and S 2 O 8 2− . Twenty new propagatingacidityfront reactions have been discovered among the possible
在基本化学考虑的基础上,表明氧阴离子产生质子的氧化还原反应是自催化的,并表现出传播的酸度前沿。通过S 2 O 3 2− 、S 4 O 6 2− 、S 2 O 4 2− 、SO 3 2− 、S 2 O 6 2− 的反应,建立并实验验证了氧化还原反应中质子产生的条件,和 N 2 H 5 + 与 BrO 3 - 、IO 3 - 、ClO 3 - 、ClO 2 和 S 2 O 8 2- 。在这些反应的可能组合中发现了 20 个新的传播酸前沿反应
Reactive oxygen species in aerobic decomposition of thiourea dioxides †
作者:Serge A. Svarovsky、Reuben H. Simoyi、Sergei V. Makarov
DOI:10.1039/a907816i
日期:——
Thiourea dioxides decompose in air-saturated alkaline solutions to give dithionite, S2O42−. Kinetics of decomposition of aminoiminomethanesulfinic acid (AIMSA), methylaminoiminomethanesulfinic acid (MAIMSA) and dimethylaminoiminomethanesulfinic acid (DMAIMSA) were studied in alkaline solutions under aerobic and anaerobic conditions. No dithionite was formed in strictly anaerobic conditions. Dithionite, however, was formed in the presence of KO2 and H2O2 under anaerobic conditions. The rate of decomposition was fastest for DMAIMSA and slowest for MAIMSA. The proposed mechanism involves the initial formation of the dioxosulfate(2−) ion, SO22−, through the heterolytic cleavage of the C–S bond. The dioxosulfate(2−) ion then reacts with dioxygen to give a series of reactive oxygen species: superoxide, peroxide and the hydroxyl radical. The expected dismutation of superoxide is important only in weakly alkaline solutions of pH less than 10. It is suggested, for the first time, that the reactive oxygen species and the sulfur leaving groups may be responsible for the toxicity observed in most thioureas.