Осмия тетроксид химические свойства, назначение, производство
Химические свойства
Osmium tetroxide is a strong oxidant. Numerous organic
substances reduce it to black osmium dioxide (OsO2) or to
osmium metal.
Физические свойства
Pale, yellow crystalline solid; chlorine-like acrid odor; monoclinic crystals having terahedral structure; density 5.1 g/cm3; melts at 40.6°C; vaporizes at 129.7°C; sublimation begins below its boiling point; vapor pressure 11 torr at 27°C; critical temperature 405°C; critical pressure 170 atm; moderately soluble in water, 7.24 g/100mL at 25°C; soluble in most organic solvents.
Использование
Osmium tetroxide is used in histopathological laboratories
to stain the adipose tissue and as a stabilizing agent in
scanning electron microscopy. In the chemical
industry, it is used as a catalyst in the organic synthesis,
particularly as the oxidizing agent in olefin-to-glycol conversion
(546, 567). In the past, osmium tetroxide in the form
of aqueous solution was used in forensic medicine to examine
fingerprints. Osmium tetroxide is also used in
medicine to treat rheumatoid arthritis.
Методы производства
Osmium tetroxide is obtained by heating, at 300–400°C,
finely divided osmium metal in the stream of air or oxygen
(546). Commercially, it is received during osmium
smelting and platinum annealing. Osmium tetroxide
may also be produced by oxidizing osmium with aqua regia
or nitric acid. It is often formed at room temperature
from osmium metal powder.
Подготовка
Osmium tetroxide is obtained as an intermediate during recovery of osmium metal from osmiridium or other noble metal minerals (See Osmium). In general, oxidation of an aqueous solution of an osmium salt or complex, such as sodium osmate with nitric acid, yields the volatile tetroxide which may be distilled out from the solution. In the laboratory, the compound can be prepared by oxidation of the osmium tetrachloride, OsCl4, or other halide solutions with sodium hypochlorite followed by distillation.
Osmium tetroxide may also be produced by heating finely divided osmium metal in a stream of oxygen or air at 300 to 400°C.
Определение
ChEBI: An osmium coordination entity consisting of four oxygen atoms bound to a central osmium atom via covalent double bonds.
Общее описание
A colorless or yellow solid with a pungent odor of chlorine. Melting point about 104°F. Boiling point 266°F (begins to sublime below melting point). Density 4.9 g / cm3. Soluble in alcohol. Toxic by inhalation and a strong irritant to the eyes and mucous membranes.
Реакции воздуха и воды
Soluble in water.
Профиль реактивности
Osmium tetraoxide is incompatible with hydrochloric acid andeasily oxidized organic materials. Contact with other materials may cause fire. . Reacted explosively with1-methylimidazole [J. Chem. Soc., Dalton Trans., 1979, 1084].
Опасность
Osmium tetroxide is poisonous by all routes of exposure. The vapor is an eye irritant and can produce tears and damage. The vapor also can cause upper respiratory tract irritation.
LD50 oral (mouse): 162 mg/kg
LCLO inhalation (mouse): 40 ppm (104 mg/m 3)/4 hr.
Угроза здоровью
TOXIC; inhalation, ingestion or skin contact with material may cause severe injury or death. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Пожароопасность
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Воспламеняемость и взрывоопасность
Noncombustible
Профиль безопасности
Poison by ingestion, inhalation, and intraperitoneal routes. Human systemic effects by inhalation: lachrymation and other eye effects and structural or functional changes in trachea or bronch. Experimental reproductive effects. Mutation data reported. Explodes on contact with 1 -methylimidazole. Catalytic decomposition of hydrogen peroxide can be hazardous. See also OSMIUM
Возможный контакт
Osmium may be alloyed with platinum
metals, iron, cobalt, and nickel; and it forms compounds
withtin and zinc. The alloy with iridium is used in
the manufacture of fountain pen points, engraving tool;
record player needles; electrical contacts; compass needles;
fine machine bearings; and parts for watch and
lock mechanisms. The metal is a catalyst in the synthesis
of ammonia; and in the dehydrogenation of organic compounds. It is also used as a stain for histological
examination of tissues. Osmium tetroxide is used as an
oxidizing agent, catalyst, and as a fixative for tissues in
electron microscopy. Other osmium compounds find use
in photography. Osmium no longer is used in incandescent
lights or in fingerprinting.
хранилище
In
particular, all work with osmium tetroxide should be conducted in a fume hood to
prevent exposure by inhalation, and splash goggles and impermeable gloves should
be worn at all times to prevent eye and skin contact. Osmium tetroxide as solid or
solutions should be stored in tightly sealed containers, and these should be placed in
secondary containers.
Несовместимости
Osmium tetroxide is a strong oxidizer.
Reacts with combustibles and reducing materials. Reacts
with hydrochloric acid to form toxic chlorine gas. Forms
unstable compounds with alkalis.
Утилизация отходов
Consult with environmental
regulatory agencies for guidance on acceptable disposal
practices. Generators of waste containing this contaminant
(≥100 kg/mo) must conform with EPA regulations
governing storage, transportation, treatment, and waste
disposal.
Осмия тетроксид препаратная продукция и сырье
сырьё
препарат