Pentachloroethane is a

chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...

chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

hydrogen Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...

, and

carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...

with the chemical formula . It is a colourless non-flammable liquid that is used as a solvent for oil and grease, in metal cleaning, and in the separation of coal from impurities.

Production and uses

Victor Regnault obtained Pentachloroethane from chlorination of various chlorinated ethanes in 1839. Pentachloroethane can be obtained by chlorination of

trichloroethylene The chemical compound trichloroethylene is a halocarbon commonly used as an industrial solvent. It is a clear, colourless non-flammable liquid with a chloroform-like sweet smell. It should not be confused with the similar 1,1,1-trichloroethane, ...

and ethylene-catalysed chlorination of

1,2-dichloroethane The chemical compound 1,2-dichloroethane, commonly known as ethylene dichloride (EDC), is a chlorinated hydrocarbon. It is a colourless liquid with a chloroform-like odour. The most common use of 1,2-dichloroethane is in the production of vinyl ...

. Pentachloroethane can also be obtained by the reaction of

acetylene Acetylene (systematic name: ethyne) is the chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure ...

and

, catalysed by

aluminium chloride Aluminium chloride, also known as aluminium trichloride, is an inorganic compound with the formula . It forms hexahydrate with the formula , containing six water molecules of hydration. Both are colourless crystals, but samples are often contam ...

and

antimony trichloride Antimony trichloride is the chemical compound with the formula SbCl3. It is a soft colorless solid with a pungent odor and was known to alchemists as butter of antimony. Preparation Antimony trichloride is prepared by reaction of chlorine with an ...

.Jian, Panming; He, Yongzhi
Method for producing pentachloroethane using acetylene and chlorine
2018. CN 108546228 A It can be made as a byproduct of

tetrachloroethylene Tetrachloroethylene, also known under the systematic name tetrachloroethene, or perchloroethylene, and many other names (and abbreviations such as "perc" or "PERC", and "PCE"), is a chlorocarbon with the formula Cl2C=CCl2 . It is a colorless liq ...

production. Pentachloroethane has limited uses as a solvent for oils and grease (especially in metal cleaning), in soil sterilisation, to remove impurities in

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...

and as a

desiccant A desiccant is a hygroscopic substance that is used to induce or sustain a state of dryness (desiccation) in its vicinity; it is the opposite of a humectant. Commonly encountered pre-packaged desiccants are solids that absorb water. Desiccant ...

agent for wood. It was formerly used as a

dry-cleaning Dry cleaning is any cleaning process for clothing and textiles using a solvent other than water. Dry cleaning still involves liquid, but clothes are instead soaked in a water-free liquid solvent. Tetrachloroethylene (perchloroethylene), known in ...

solvent for a short time. It is rarely used since there are safer and more economical alternatives such as tetrachloroethylene. It can be used as a precursor to

. ''Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens'', , .

Activated carbon Activated carbon, also called activated charcoal, is a form of carbon commonly used to filter contaminants from water and air, among many other uses. It is processed (activated) to have small, low-volume pores that increase the surface area avail ...

-catalysed reaction of pentachloroethane and

calcium chloride Calcium chloride is an inorganic compound, a salt with the chemical formula . It is a white crystalline solid at room temperature, and it is highly soluble in water. It can be created by neutralising hydrochloric acid with calcium hydroxide. Ca ...

gives tetrachloroethylene by

dehydrochlorination In chemistry, dehydrohalogenation is an elimination reaction which removes a hydrogen halide from a substrate. The reaction is usually associated with the synthesis of alkenes, but it has wider applications. Dehydrohalogenation from alkyl hali ...

Safety

Although it is not flammable, pentachloroethane can oxidise to give

phosgene Phosgene is the organic chemical compound with the formula COCl2. It is a toxic, colorless gas; in low concentrations, its musty odor resembles that of freshly cut hay or grass. Phosgene is a valued and important industrial building block, espe ...

and

trichloroacetyl chloride Trichloroacetyl chloride is the acyl chloride of trichloroacetic acid. It can be formed by reacting chlorine with acetyl chloride Acetyl chloride (CH3COCl) is an acyl chloride derived from acetic acid. It belongs to the class of organic compo ...

in presence of oxygen at high temperatures. Pentachloroethane is not biodegradable and it can be toxic to aquatic life. It is toxic for humans.

References

{{Reflist

External links

CDC - NIOSH Pocket Guide to Chemical Hazards
Chloroalkanes Halogenated solvents Substances discovered in the 19th century