Серебро ацетат химические свойства, назначение, производство
Описание
Silver acetate is an organic compound with the empirical formula CH3COOAg (or AgC2H3O2). It is a photosensitive, white crystalline solid. It is a useful reagent in the laboratory as a water soluble source of silver lacking an oxidizing anion. It has been used in some antismoking drugs.
Химические свойства
Off-White/Brown Crystalline Powder
Использование
In the health field, silver acetate-containing products have been used in gum, spray, and lozenges to deter smokers from smoking. The silver in these products, when mixed with smoke, creates an unpleasant metallic taste in the smoker's mouth, thus deterring them from smoking. Lozenges containing 2.5 mg of silver acetate showed "modest efficacy" on 500 adult smokers tested over a three-month period. However, over a period of 12 months, prevention failed. In 1974, silver acetate was first introduced in Europe as an over-thecounter smoking-deterrent lozenge (Repaton) and then three years later as a chewing gum (Tabmint).
Реакции
3 – 1 - Carbonylation
Silver acetate, when combined with carbon monoxide (CO), can induce the carbonylation of primary and secondary amines. Other silver salts can be used but the acetate gives the best yield.
2 R2NH + 2 AgOAc + CO → [R2N]2CO + 2 HOAc + 2 Ag
3 – 2 - Hydrogenation
Silver acetate in a solution of pyridine absorbs hydrogen and is reduced to metallic silver.
3 – 3 - Direct ortho - arylation
Silver acetate is a useful reagent for direct ortho-arylation (to install two adjacent substituents on an aromatic ring) for of benzylamines and N-methylbenzylamines. The reaction is palladiumcatalized and requires a slight excess of silver acetate.This reaction is shorter than previous ortho-arylation methods.
Всемирная организация здравоохранения(ВОЗ)
Silver acetate has been used as a disinfectant and as an antismoking
aid. It was refused registration in Cyprus on the grounds that prolonged use of silver salts can cause permanent argyria and that no well-controlled trials
have been performed to establish the safety and efficacy of the preparation. It
remains registered as an aid to stopping smoking in Canada and the United States.
Общее описание
White crystalline plates. Light sensitive. Density 3.26 g / cm3.
Реакции воздуха и воды
Slightly soluble in water.
Профиль реактивности
Silver acetate is freely soluble in dilute nitric acid [Merck]. Can serve as an oxidizing agent.
Опасность
Toxic material.
Угроза здоровью
Inhalation of dust irritates nose and throat. Contact with eyes or skin causes irritation. If continued for a long period, ingestion or inhalation of silver compounds can cause permanent discoloration of skin (argyria).
Безопасность
The LD50 of silver acetate in mice is 36.7 mg/kg. Low doses of silver acetate in mice produced hyper-excitability, ataxia, central nervous system depression, labored breathing, and even death. The U.S. FDA recommends that silver acetate intake be limited to 756 mg over a short period of time; excessive intake may cause argyria.
Методы очистки
Shake it with acetic acid for three days, and the process is repeated with fresh acid. The solid is then dried in a vacuum oven at 40o for 48hours. It has also been recrystallised from water containing a trace of acetic acid, and dried in air. Store it in the dark. [Beilstein 2 IV 112.]
Серебро ацетат препаратная продукция и сырье
сырьё
препарат