Interaction of the unsaturated sulfones with azinium ylides
1. Introduction In Japan the energy self-efficiency is very low: only 6%. Hydrogen (H2) has been expected as a new and alternative energy source to imported one, such as petroleum resources. Now hydrogen energy comes into the practical use in the field of the fuel cell. Hydrogen must be extracted from other sources, for example, water, fossil fuel, and so on. Hydrogen is obtained from water by using electronic or thermal or photo energy in most cases, whereas it is well-known that hydrogen is given by the oxidation reaction of silicon in alkaline aqueous solution: Si + 2OH- + H2O → SiO32- + 2H2 Free silicon (Si) is not only used in the steel refining, aluminum-casting in the field of fine chemical industries but also is used as a material in semiconductor electronics. However, a lot of used silicon is thrown away as a waste, being not reused and recycled. In this study we try to apply a waste silicon to obtain hydrogen based on the above reaction. The purpose of the study is to develop a safe and convenient manufacturing method to generate hydrogen for an energy source of the fuel cell.
Findings of new oscillations in BR reaction
The Briggs Rauscher reaction, i. e., BR reaction, which is one of the oscillation reactions, produces iodide ion and iodine repeatedly. Continual color changes of the solution from colorless to deep blue, and vice versa, are observed during the reaction due to the so-called “iodine test” reaction. In this work, we studied the effects of the presence of the redox active indicators on the oscillation behavior of the BR reaction. To the reaction mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch, which are used for the general BR reaction as added a redox active reagent (indicator). Then, the changes in color and voltage of the reaction solution were recorded by a photosensor of the LEGO MINDSTORMS and a voltmeter using Pt electrodes. Under general reaction conditions, the oscillation reaction continued for ca. 5 minutes, including 18 times of oscillations. When an indicator, such as BTB, was added instead of starch to the reaction solution, splits of the voltage wave were observed, which should be a kind of new oscillation. Moreover, we found that the addition of K3[Fe(CN)6], which exhibits high redox activity, in the reaction solution instead of starch made the life-time and the numbers of the oscillation in the reaction greater by 3 times (14 min.) in time and more than 4 times (81 times) in the frequency. It’s also a kind of new oscillation. These results suggested that the oxidation-reduction reactions by the addition of ferricyanate ion effectively promotes the redox process of iodine and iodide ion. The experiments we wrote above were conducted without starch. Thus, as a reference, we conducted the same experiments under the presence of starch and got interesting results. We also studied the effects of K4[Fe(CN)6], suggeting that not only redox reaction between ferricyanide and ferrocyanide ion, but also the redox reaction with BR solution should occur in these reactions.