- Green preparation method of diquat anionic salt
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The invention belongs to the technical field of chemistry, and discloses a green preparation method of diquat anionic salt. The method comprises the following steps of performing reaction on diquat dibromide mother liquid and oxidization agents in the presence of hydrochloric acid or sulfuric acid to obtain reaction liquid containing diquat dichloride or diquat hydrosulfate; filtering reaction liquid; performing pH regulation and concentration treatment on filter liquid to obtain diquat dichloride mother liquid or diquat hydrosulfate mother liquid; mixing filter cake with organic solvents; introducing ethylene for reaction until the system pressure is unchanged; filtering reaction liquid to obtain filter liquid containing 1,2-dibromoethane and diquat dibromide solid; performing washing anddrying on the diquat dibromide; preparing diquat dibromide mother liquid; recovering filter liquid to obtain 1,2-dibromoethane; performing dipyridyl reaction to prepare diquat dibromide. The method provided by the invention is simple, and is suitable for industrial production; the cationic loss rate is lower than 0.5 percent; the bromine recovery rate is higher than 96 percent, so that the cyclicutilization of bromine is realized; the bromine waste is avoided.
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Paragraph 0049; 0050; 0057; 0058; 0061; 0062
(2019/02/03)
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- Preparation method of 1, 1'-ethylene-2, 2'-dipyridyl dichloride salt
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The invention belongs to the field of chemistry, and discloses a preparation method of 1, 1'-ethylene-2, 2'-dipyridyl dichloride salt. The method comprises the following steps: mixing a diquat dibromide salt water solution and hydrochloric acid; dropwise adding to a mixed solution of an organic solvent, a bromine absorbent and an oxidant to react to obtain 1, 1'-ethylene-2, 2'-dipyridyl dichloridesalt. The synthesizing method is simple and suitable for industrial production; the yield of diquat dichloride salt is beyond 98%; meanwhile, a bromide byproduct which can be sold as goods can be produced; the bromine recovery rate is beyond 95%. Therefore, the cost is reduced; the waste of the bromine resource is avoided.
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Paragraph 0049; 0050; 0051; 0052; 0053-0075
(2018/03/26)
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- Free-energy dependence of electron-transfer rate constants at Si/liquid interfaces
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The interfacial energetics and kinetics of n-type Si electrodes in contact with a series of one-electron, outer-sphere redox couples were investigated using the differential capacitance vs potential and current density vs potential measurements, respectively. The differential capacitance vs potential measurements were essentially independent of the ac frequency imposed on the interface, with linear Bode plots between ≈103 and ≈105 Hz. The current density vs potential plots exhibited first-order kinetic dependence on the concentration of electrons at the semiconductor surface and a first-order kinetic dependence on the concentration of acceptors in the solution.
- Fajardo,Lewis
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p. 11136 - 11151
(2007/10/03)
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