Carbon tetrachloride

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Carbon tetrachloride
Structural formula of carbon tetrachlorideSpace-filling model carbon tetrachloride
Carbon tetrachloride
Identifiers
CAS number56-23-5 YesY
PubChem5943
ChemSpider5730 YesY
UNIICL2T97X0V0 YesY
EC number200-262-8
UN number1846
KEGGC07561 YesY
ChEBICHEBI:27385 YesY
ChEMBLCHEMBL44814 YesY
RTECS numberFG4900000
Jmol-3D imagesImage 1
Properties
Molecular formulaCCl4
Molar mass153.82 g mol−1
Appearancecolourless liquid
Odorether-like odor
Density1.5867 g cm−3 (liquid)

1.831 g cm−3 at −186 °C (solid)
1.809 g cm−3 at −80 °C (solid)

Melting point−22.92 °C (−9.26 °F; 250.23 K)
Boiling point76.72 °C (170.10 °F; 349.87 K)
Solubility in water0.097 g/100 mL (0 °C)
0.081 g/100 mL (25 °C)
Solubilitysoluble in alcohol, ether, chloroform, benzene, naphtha, CS2, formic acid
log P2.64
Vapor pressure11.94 kPa at 20 °C
kH2.76x10−2 atm-cu m/mol
Refractive index (nD)1.4607
Dipole moment0 D
Structure
Crystal structureMonoclinic
Molecular shapeTetrahedral
Thermochemistry
Specific
heat capacity
C
132.6 J/mol K
Std molar
entropy
So298
214.4 J/mol K
Std enthalpy of
formation
ΔfHo298
-139.3 kJ/mol
Gibbs free energy ΔG-686 kJ/mol
Hazards
MSDSExternal MSDS
EU Index602-008-00-5
EU classificationToxic T Dangerous for the Environment (Nature) N
R-phrasesR23/24/25, R40, R48/23, R59, R52/53
S-phrases(S1/2), S23, S36/37, S45, S59, S61
NFPA 704
Flash pointNon-flammable
LD502350 mg/kg
Related compounds
Other cationsSilicon tetrachloride
Germanium tetrachloride
Tin tetrachloride
Lead tetrachloride
Related chloromethanesChloromethane
Dichloromethane
Chloroform
Related compoundsTetrafluoromethane
Tetrabromomethane
Tetraiodomethane
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral dataUV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references
 
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Carbon tetrachloride
Structural formula of carbon tetrachlorideSpace-filling model carbon tetrachloride
Carbon tetrachloride
Identifiers
CAS number56-23-5 YesY
PubChem5943
ChemSpider5730 YesY
UNIICL2T97X0V0 YesY
EC number200-262-8
UN number1846
KEGGC07561 YesY
ChEBICHEBI:27385 YesY
ChEMBLCHEMBL44814 YesY
RTECS numberFG4900000
Jmol-3D imagesImage 1
Properties
Molecular formulaCCl4
Molar mass153.82 g mol−1
Appearancecolourless liquid
Odorether-like odor
Density1.5867 g cm−3 (liquid)

1.831 g cm−3 at −186 °C (solid)
1.809 g cm−3 at −80 °C (solid)

Melting point−22.92 °C (−9.26 °F; 250.23 K)
Boiling point76.72 °C (170.10 °F; 349.87 K)
Solubility in water0.097 g/100 mL (0 °C)
0.081 g/100 mL (25 °C)
Solubilitysoluble in alcohol, ether, chloroform, benzene, naphtha, CS2, formic acid
log P2.64
Vapor pressure11.94 kPa at 20 °C
kH2.76x10−2 atm-cu m/mol
Refractive index (nD)1.4607
Dipole moment0 D
Structure
Crystal structureMonoclinic
Molecular shapeTetrahedral
Thermochemistry
Specific
heat capacity
C
132.6 J/mol K
Std molar
entropy
So298
214.4 J/mol K
Std enthalpy of
formation
ΔfHo298
-139.3 kJ/mol
Gibbs free energy ΔG-686 kJ/mol
Hazards
MSDSExternal MSDS
EU Index602-008-00-5
EU classificationToxic T Dangerous for the Environment (Nature) N
R-phrasesR23/24/25, R40, R48/23, R59, R52/53
S-phrases(S1/2), S23, S36/37, S45, S59, S61
NFPA 704
Flash pointNon-flammable
LD502350 mg/kg
Related compounds
Other cationsSilicon tetrachloride
Germanium tetrachloride
Tin tetrachloride
Lead tetrachloride
Related chloromethanesChloromethane
Dichloromethane
Chloroform
Related compoundsTetrafluoromethane
Tetrabromomethane
Tetraiodomethane
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral dataUV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Carbon tetrachloride, also known by many other names (the most notable being tetrachloromethane (also recognized by the IUPAC), carbon tet in the cleaning industry, Halon-104 in firefighting and Refrigerant-10 in HVACR), is the inorganic compound with the chemical formula CCl4. It was formerly widely used in fire extinguishers, as a precursor to refrigerants, and as a cleaning agent. It is a colourless liquid with a "sweet" smell that can be detected at low levels.

History and synthesis[edit]

Carbon tetrachloride was originally synthesized by the French chemist Henri Victor Regnault in 1839 by the reaction of chloroform with chlorine,[1] but now it is mainly produced from methane:

CH4 + 4 Cl2 → CCl4 + 4 HCl

The production often utilizes by-products of other chlorination reactions, such as from the syntheses of dichloromethane and chloroform. Higher chlorocarbons are also subjected to "chlorinolysis:"

C2Cl6 + Cl2 → 2 CCl4

Prior to the 1950s, carbon tetrachloride was manufactured by the chlorination of carbon disulfide at 105 to 130 °C:[2]

CS2 + 3Cl2 → CCl4 + S2Cl2

The production of carbon tetrachloride has steeply declined since the 1980s due to environmental concerns and the decreased demand for CFCs, which were derived from carbon tetrachloride. In 1992, production in the U.S.-Europe-Japan was estimated at 720,000 tonnes.[2]

Properties[edit]

In the carbon tetrachloride molecule, four chlorine atoms are positioned symmetrically as corners in a tetrahedral configuration joined to a central carbon atom by single covalent bonds. Because of this symmetrical geometry, CCl4 is non-polar. Methane gas has the same structure, making carbon tetrachloride a halomethane. As a solvent, it is well suited to dissolving other non-polar compounds, fats, and oils. It can also dissolve iodine. It is somewhat volatile, giving off vapors with a smell characteristic of other chlorinated solvents, somewhat similar to the tetrachloroethylene smell reminiscent of dry cleaners' shops.

Solid tetrachloromethane has 2 polymorphs: crystalline II below −47.5 °C (225.6 K) and crystalline I above −47.5 °C.[3]

At −47.3 °C it has monoclinic crystal structure with space group C2/c and lattice constants a = 20.3, b = 11.6, c = 19.9 (.10−1 nm), β = 111°.[4] With a specific gravity greater than 1, carbon tetrachloride will be present as a dense nonaqueous phase liquid if sufficient quantities are spilled in the environment.

Uses[edit]

Historically, Carbon Tatrachloride was used for a variety of purposes. However, once it became apparent that carbon tetrachloride exposure had severe adverse health effects, such as causing fulminant hepatic necrosis, safer alternatives such as tetrachloroethylene were found for these applications, and its use in these roles declined from about 1940 onward. Carbon tetrachloride persisted as a pesticide to kill insects in stored grain, but in 1970 it was banned in consumer products in the United States.

Prior to the Montreal Protocol, large quantities of carbon tetrachloride were used to produce the chlorofluorocarbon refrigerants R-11 (trichlorofluoromethane) and R-12 (dichlorodifluoromethane). However, these refrigerants play a role in ozone depletion and have been phased out. Carbon tetrachloride is still used to manufacture less destructive refrigerants. Carbon tetrachloride has also been used in the detection of neutrinos.

Current uses[edit]

Carbon tetrachloride is one of the most potent hepatotoxins (toxic to the liver), and is widely used in scientific research to evaluate hepatoprotective agents.[5][6]

Carbon tetrachloride has practically no flammability at lower temperatures. Under high temperatures in air, it forms poisonous phosgene. In organic chemistry, carbon tetrachloride serves as a source of chlorine in the Appel reaction.

Because it has no C-H bonds, carbon tetrachloride does not easily undergo free-radical reactions. Hence, it is a useful solvent for halogenations either by the elemental halogen or by a halogenation reagent such as N-bromosuccinimide (these conditions are known as Wohl-Ziegler Bromination).

It is used as a solvent in synthetic chemistry research, but, because of its adverse health effects, it is no longer commonly used, and in general chemists try to replace it with other solvents.[5] It is sometimes useful as a solvent for infrared spectroscopy, because there are no significant absorption bands > 1600 cm−1. Because carbon tetrachloride does not have any hydrogen atoms, it was historically used in proton NMR spectroscopy. However, carbon tetrachloride is toxic, and its dissolving power is low.[7] Its use has been largely superseded by deuterated solvents. Use of carbon tetrachloride in determination of oil has been replaced by various other solvents, such as tetrachloroethylene.[5]

Historical uses[edit]

A brass, Pyrene carbon-tetrachloride, fire extinguisher.

In 1910, The Pyrene Manufacturing Company of Delaware filed a patent to use carbon tetrachloride to extinguish fires.[8] The liquid vaporized and extinguished the flames by inhibiting the chemical chain reaction of the combustion process (it was an early 20th-century presupposition that the fire suppression ability of carbon tetrachloride relied on oxygen removal.) In 1911, they patented a small, portable extinguisher that used the chemical.[9] This consisted of a brass bottle with an integrated handpump that was used to expel a jet of liquid toward the fire. As the container was unpressurized, it could be easily refilled after use.[10] Carbon tetrachloride was suitable for liquid and electrical fires and the extinguishers were often carried on aircraft or motor vehicles.

A formerly common form of fire extinguishers consisted of a glass globe, known as a "fire grenades", and were filled with either carbon tetrachloride or salt-water. It was intended that the bulb simply be thrown at the base of the flames.

A glass globe "fire grenade"

Carbon tetrachloride was widely used as a dry cleaning solvent, as a refrigerant, and in lava lamps.[11]

One specialty use of carbon tetrachloride was in stamp collecting, to reveal watermarks on postage stamps without damaging them. A small amount of the liquid was placed on the back of a stamp, sitting in a black glass or obsidian tray. The letters or design of the watermark could then be clearly seen.

Safety[edit]

Time-series of atmospheric concentrations of CCl4 (Walker et al., 2000).

Exposure to high concentrations of carbon tetrachloride (including vapor) can affect the central nervous system, degenerate the liver[6] and kidneys[12] and may result (after prolonged exposure) in coma and even death.[13] Chronic exposure to carbon tetrachloride can cause liver[14][15] and kidney damage and could result in cancer.[16] See material safety data sheets.[17]

In 2008, a study of common cleaning products found the presence of carbon tetrachloride in "very high concentrations" (up to 101 mg/m3) as a result of manufacturers' mixing of surfactants or soap with sodium hypochlorite (bleach).[18]

Like many other volatile substances, carbon tetrachloride is prone to misuse by inhalation, due to its possible depressant and/or dissociative effect upon the central nervous system. Use of carbon tetrachloride in this manner presents serious health risks, and may result in toxic effects described above.

Carbon tetrachloride is also both ozone-depleting[19] and a greenhouse gas.[20] However, since 1992[21] its atmospheric concentrations have been in decline for the reasons described above (see also the atmospheric time-series figure). CCl4 has an atmospheric lifetime of 85 years.[22]

References[edit]

  1. ^ V. Regnault (1839) "Sur les chlorures de carbone CCl et CCl2 " (On the chlorides of carbon CCl and CCl2 ), Annales de Chimie et de Physique, vol. 70, pages 104-107. Reprinted in German as: V. Regnault (1839). "Ueber die Chlorverbindungen des Kohlenstoffs, C2Cl2 und CCl2 (On the chlorine compounds of carbon, C2Cl2 und CCl2)". Annalen der Pharmacie 30 (3): 350–352. doi:10.1002/jlac.18390300310. 
  2. ^ a b Manfred Rossberg, Wilhelm Lendle, Gerhard Pfleiderer, Adolf Tögel, Eberhard-Ludwig Dreher, Ernst Langer, Heinz Jaerts, Peter Kleinschmidt, Heinz Strack, Richard Cook, Uwe Beck, Karl-August Lipper, Theodore R. Torkelson, Eckhard Löser, Klaus K. Beutel, “Chlorinated Hydrocarbons” in Ullmann's Encyclopedia of Industrial Chemistry, 2006 Wiley-VCH, Weinheim.doi:10.1002/14356007.a06_233.pub2
  3. ^ Carbon tetrachloride
  4. ^ F. Brezina, J. Mollin, R. Pastorek, Z. Sindelar. Chemicke tabulky anorganickych sloucenin (Chemical tables of inorganic compounds). SNTL, 1986.
  5. ^ a b c Use of Ozone Depleting Substances in Laboratories. TemaNord 516/2003.
  6. ^ a b Seifert WF, Bosma A, Brouwer A, et al (January 1994). "Vitamin A deficiency potentiates carbon tetrachloride-induced liver fibrosis in rats". Hepatology 19 (1): 193–201. doi:10.1002/hep.1840190129. PMID 8276355. 
  7. ^ W. Reusch. "Introduction to Nuclear Magnetic Resonance Spectroscopy". Virtual Textbook of Organic Chemistry. Michigan State University. 
  8. ^ U.S. Patent 1,010,870, filed April 5, 1910.
  9. ^ U.S. Patent 1,105,263, filed Jan 7, 1911.
  10. ^ "Pyrene Fire Extinguishers". Vintage Fire Extinguishers. Retrieved 23 December 2009. 
  11. ^ Doherty RE (2000). "A History of the Production and Use of Carbon Tetrachloride, Tetrachloroethylene, Trichloroethylene and 1,1,1-Trichloroethane in the United States: Part 1—Historical Background; Carbon Tetrachloride and Tetrachloroethylene". Environmental Forensics 1 (1): 69–81. doi:10.1006/enfo.2000.0010. 
  12. ^ Liu KX, Kato Y, Yamazaki M, Higuchi O, Nakamura T, Sugiyama Y (April 1993). "Decrease in the hepatic clearance of hepatocyte growth factor in carbon tetrachloride-intoxicated rats". Hepatology 17 (4): 651–60. doi:10.1002/hep.1840170420. PMID 8477970. 
  13. ^ Recknagel R.O., Glende E.A., Dolak J.A., Waller R.L. (1989). "Mechanism of Carbon-tetrachloride Toxicity". Pharmacology Therapeutics 43 (43): 139–154. doi:10.1016/0163-7258(89)90050-8. 
  14. ^ Recknagel RO (June 1967). "Carbon tetrachloride hepatotoxicity". Pharmacol. Rev. 19 (2): 145–208. PMID 4859860. 
  15. ^ Masuda Y (October 2006). "[Learning toxicology from carbon tetrachloride-induced hepatotoxicity]". Yakugaku Zasshi (in Japanese) 126 (10): 885–99. doi:10.1248/yakushi.126.885. PMID 17016019. [dead link]
  16. ^ Rood AS, McGavran PD, Aanenson JW, Till JE (August 2001). "Stochastic estimates of exposure and cancer risk from carbon tetrachloride released to the air from the rocky flats plant". Risk Anal. 21 (4): 675–95. doi:10.1111/0272-4332.214143. PMID 11726020. 
  17. ^ Material Safety Data Sheet, Carbon tetrachloride at Fisher Scientific
  18. ^ Odabasi M (2008). "Halogenated Volatile Organic Compounds from the Use of Chlorine-Bleach-Containing Household Products". Environmental Science & Technology 42 (5): 1445–51. Bibcode:2008EnST...42.1445O. doi:10.1021/es702355u. 
  19. ^ Fraser P. (1997). "Chemistry of stratospheric ozone and ozone depletion". Australian Meteorological Magazine 46 (3): 185–193. 
  20. ^ Evans WFJ, Puckrin E (1996). "A measurement of the greenhouse radiation associated with carbon tetrachloride (CCl4)". Geophysical Research Letters 23 (14): 1769–72. Bibcode:1996GeoRL..23.1769E. doi:10.1029/96GL01258. 
  21. ^ Walker, S. J., R. F. Weiss & P. K. Salameh (2000). "Reconstructed histories of the annual mean atmospheric mole fractions for the halocarbons CFC-11, CFC-12, CFC-113 and carbon tetrachloride". Journal of Geophysical Research 105: 14285–96. Bibcode:2000JGR...10514285W. doi:10.1029/1999JC900273. 
  22. ^ The Atlas of Climate Change (2006) by Kirstin Dow and Thomas E. Downing ISBN 978-0-520-25558-6

External links[edit]