Углерод тетрабромид химические свойства, назначение, производство
Описание
Carbon tetrabromide is considered a highly toxic chemical,
may be fatal if inhaled, swallowed, or absorbed through skin.
It is metabolized in vitro to produce carbon monoxide but
the in vivo significance has not been established. Under
anaerobic reducing conditions it forms complexes with
ferrous cytochrome P450. Carbon monoxide is detected as
a metabolic product of the interaction. Carbon tetrabromide’s
production and use in organic syntheses may
result in its release to the environment through various waste
streams. Carbon tetrabromide has been isolated from red
algae, Asparagopsis toxiformis, found in the ocean near Hawaii.
It was detected in water from treated chlorinated seawater
used for drinking at oil platforms. Occupational exposure to
carbon tetrabromide may occur through inhalation and
dermal contact with this compound at workplaces where it is
produced or used. The general population may be exposed to
carbon tetrabromide via ingestion of drinking water. Acute
exposures to high concentrations may cause upper respiratory
tract irritation and injury to lungs, liver (hepatotoxicity)
and kidneys (nephrotoxicity). Chronic exposure effects at
very low levels will be almost entirely limited to liver injury.
It is a potent lachrymator even at low exposure concentrations.
Although carbon tetrabromide may release bromine
ions during metabolism, clinical bromism is not expected to
occur.
Химические свойства
Carbon tetrabromide, is a colorless powder,
white crystalline solid, or yellow-brown crystals. Slight
odor
Использование
Carbon tetrabromide is used to a limited extent as a chemical
intermediate. It has been isolated from red algae, Asparagopsis
toxiformis, found in the ocean near Hawaii.
Определение
ChEBI: A one-carbon compound substituted by 4 bromo groups.
прикладной
Carbon tetrabromide (CBr4) is a multifunctional chemical reagent widely used in chemical and pharmaceutical industries. It mainly includes:
(1) As a thiophilic reagent, it promotes the one-pot oxidative condensation of amines with N,N'-disubstituted thioureas to give a variety of guanidine derivatives[1].
(2) As a bromine radical precursor, used in the electrochemical radical bromination and cyclisation sequence of enoic acid to prepare bromomethylated γ-lactone derivatives[2].
(3) As a precursor of hydrogen atom transfer reagent, used to generate aromatic carbonyl compounds[3].
(4) As raw materials or intermediates for organic synthesis. Synthesis of N-sulfonylformamidine from CBr4 and formamide under UVA irradiation. Activated imine intermediates (Vilsmeier-Haack reagent derivatives) were obtained via a photoinduced reaction between CBr4 and formamide[4].
Общее описание
A colorless crystalline solid. Much more dense than water and insoluble in water. Toxic by ingestion. Vapors are narcotic in high concentration. Used to make other chemicals.
Реакции воздуха и воды
Insoluble in water.
Профиль реактивности
Carbon tetrabromide is incompatible with the following: Strong oxidizers, hexacyclohexyldilead, lithium .
Опасность
A poison; narcotic in high concentration.
Liver damage, eye, skin, and upper respiratory tract
irritant.
Угроза здоровью
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. 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. Containers may explode when heated. Runoff may pollute waterways.
Профиль безопасности
Poison by
subcutaneous and intravenous routes.
Narcotic in high concentration. Mixture
with Li particles is an impact-sensitive
explosive. Explodes on contact with
hexacyclohexylddead. When heated to
decomposition it emits toxic fumes of Br-.
See also CHLORINATED
HYDROCARBONS, ALIPHATIC.
Экологическая судьба
Carbon tetrabromide inhibits protein synthesis and causes
lipid peroxidation, both of which may be involved in cell injury
or death mediated by free radicals.
Перевозки
UN2516 Carbon tetrabromide, Hazard Class:
6.1; Labels: 6.1-Poisonous materials.
Методы очистки
Reactive bromide is removed from CBr4 by refluxing with dilute aqueous Na2CO3, then steam distilling, crystallising from EtOH, and drying in the dark under vacuum. [Sharpe & Walker J Chem Soc 157 1962.] It can be sublimed at 70o and low pressure. [Beilstein 1 IV 85.]
Несовместимости
Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides, lithium and hexacyclohexyldiilead, since violent reactions may occur.
Утилизация отходов
Purify by distillation and
return to suppliers.
Углерод тетрабромид препаратная продукция и сырье
сырьё
препарат