Silver acetate

Description

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.

Chemical properties

Off-White/Brown Crystalline Powder

The Uses of Silver acetate

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).

The Uses of Silver acetate

Oxidizing agent for use in liquid ammonia: Kline, Kershner, Inorg. Chem. 5, 932 (1966).

The Uses of Silver acetate

It is a reagent in the laboratory as a source of silver ions lacking an oxidizing anion. It is a reagent for direct ortho-arylation, and for conversion of organohalogen compounds into alcohols. Woodward cis-hydroxylation reaction employs silver acetate and iodine for selective conversin of alkenes into cis-diols. Silver acetate is the more preferred reagent for facile carbonylation of primary and secondary amines. It is also employed in the preparation of highly reflective, conductive silvered polymer films.

What are the applications of Application

Silver acetate is a cycloaddition catalyst and conductive film reagent

Reactions

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.

brand name

Smokerette;Tabmint.

World Health Organization (WHO)

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.

General Description

White crystalline plates. Light sensitive. Density 3.26 g / cm3.

Air & Water Reactions

Slightly soluble in water.

Reactivity Profile

Silver acetate is freely soluble in dilute nitric acid [Merck]. Can serve as an oxidizing agent.

Hazard

Toxic material.

Health Hazard

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).

Safety

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.

Synthesis

The silver acetate salt can be synthesized by the reaction of acetic acid and silver carbonate at 45 – 60 °C. After allowing cooling to room temperature, the solid product precipitates.
2 CH₃CO₂H + Ag₂CO₃ → 2 AgO₂CCH₃ + H₂O + CO₂
It can also be precipitated from concentrated aqueous solutions of silver nitrate by treatment with a solution of sodium acetate.
The structure of silver acetate consists of 8-membered Ag₂O₄C₂ rings formed by a pair of acetate ligands bridging a pair of silver centres.

Purification Methods

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.]