Железо (III) фторид

Химические свойства

Iron(III) fluoride is only sparingly soluble in water and insoluble in alcohol and ether. When heated in hydrogen it is reduced to iron(II) fluoride and thence to the metal. In aqueous solution the hydrolysis appears to be very slight ; in the presence of alkali metal fluorides, complex fluorides of types MFeF4, M2FeF5.xH2O and M3FeF6 can be crystallized. The magnetic behaviour of FeF3 is complicated; between 63° and 293°K the susceptibility is field strength dependent. The trihydrate has a magnetic moment μ = 2-25 B.M. at 300°K.

Использование

As catalyst in organic reactions.

Подготовка

This can be prepared by the action of fluorine on the metal, iron(II), or iron(III) chloride or by dehydration of the hydrate (obtained from aqueous solution) by heating in a current of hydrogen fluoride. A convenient laboratory preparation involves the reaction of hydrogen fluoride with anhydrous iron(III) chloride at room temperature :
FeCl3+3HF→ FeF3+3HCl
When crystallized from aqueous solution (iron(III) "hydroxide" and aqueous hydrofluoric acid) it forms the pale pink 4?-hydrate (room temperature evaporation) and the pink 3-hydrate (evaporation by heating).

Общее описание

IRON (II) FLUORIDE is a green crystalline solid. IRON (II) FLUORIDE is slightly soluble in water. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. IRON (II) FLUORIDE is used in ceramics.

Реакции воздуха и воды

Slightly soluble in water forming acidic solutions.

Профиль реактивности

Acidic salts, such as IRON (II) FLUORIDE, are generally soluble in water. The resulting solutions contain moderate concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. IRON (II) FLUORIDE is used to catalyze organic reactions.

Опасность

Strong irritant.

Угроза здоровью

INHALATION: Inorganic fluorides are generally irritating. INGESTION: Ingestion of iron compounds can cause: lethargy, retching, vomiting, tarry stools, fast and weak pulse, low blood pressure, and coma.

Пожароопасность

Behavior in Fire: May give off fumes or vapors of fluorides; hydrofluoric acid.

Профиль безопасности

Moderately toxic by intraperitoneal route. Mutation data reported. When heated to decomposition it emits toxic fumes of F-. See also FLUORIDES.