Is CH3Cl a hydrocarbon

chloroform

chloroform (systematic name Trichloromethane) is a chlorinated hydrocarbon with the empirical formula CHCl3.

history

Manufacturing

Industrially, chloroform is produced by heating chlorine with methane or chloromethane to 400–500 ° C. At this temperature, radical substitution takes place up to carbon tetrachloride:

Methane reacts with chlorine with the formation of hydrogen chloride first to form chloromethane, then further to dichloromethane, trichloromethane and finally to carbon tetrachloride. The result of the process is a mixture of the four chloromethanes, which can be separated by distillation. Industrially produced chloroform of technical purity also contains bromine and ethane derivatives (e.g. bromochloromethane, bromodichloromethane, 1,2-dichloroethane) as impurities[23] as well as ethanol (<1%) or pentenes (<0.1%), which are added artificially as a stabilizer in order to intercept the phosgene that is formed when stored in air and light.[24]

Alternatively, chloroform can be obtained by photochlorination of methane. In the laboratory, chloroform can be represented by the reaction of sodium hypochlorite with acetone, a haloform reaction.[25]

properties

Physical Properties

Trichloromethane is a colorless, non-flammable, volatile liquid with a sweet odor. The melting point is −63 ° C, the boiling point under normal pressure is 61 ° C. According to Antoine, the vapor pressure function is logically10(P) = A− (B / (T + C)) (P in bar, T in K) with A = 4.20772, B = 1233.129 and C = −40.953 in the temperature range from 215 to 334 K and with A = 4.56992, B = 1486.455 and C = −8.612 in the temperature range from 334.4 to 527 K.[26] It has a greater density than water and is only sparingly soluble in it. The miscibility with water is limited. With increasing temperature, the solubility of chloroform in water decreases or the solubility of water in chloroform increases.[27]

Solubilities between chloroform and water[27]
Temperature (in ° C) 09,519,629,539,349,259,2
Chloroform in water (mass fraction in%) 1,020,930,820,790,740,770,79
Water in chloroform (mass fraction in%) 0,03650,05270,06610,08410,11080,13530,1672

The compound forms azeotropically boiling mixtures with a number of solvents. The azeotropic compositions and boiling points can be found in the following table. No azeotropes will be using n-Pentane, n-Heptane, cyclohexane, benzene, toluene, n-propanol, i-butanol, carbon tetrachloride, diethyl ether, 1,4-dioxane, n-butyl acetate, acetic acid, acetonitrile, nitrobenzene, carbon disulfide and pyridine.[28]

Chemical properties

Chloroform is photochemically decomposed by oxygen under the influence of light, producing phosgene, chlorine and hydrogen chloride. Commercially available chloroform contains 0.5–1.0% ethanol as a stabilizer to chemically intercept phosgene.

Its structure (CHX3) forms a homologous series with fluoroform, bromoform and iodoform.

Reaction with acetone

Acetone and chloroform must not be mixed in higher concentrations because the presence of traces of alkaline substances can lead to a very violent reaction in which 1,1,1-trichloro-2-methyl-2-propanol (| α, α , α-trichlorotert-Butanol) is formed. For this reason, too, chlorinated and non-chlorinated solvent waste should be collected separately in the laboratory.[29]

use

Chloroform is primarily used as a solvent and for the production of chlorofluorocarbons (CFC) is used.

With alcoholic potash and ammonia, potassium cyanide is formed when heated.[30] If primary amines are used instead of ammonia, isonitriles are obtained. With this reaction discovered by August Wilhelm von Hofmann, primary amines can also be qualitatively detected, because the isonitriles can be recognized by a strong and foul odor.[31]

In chemical synthesis it is used to produce dichlorocarbene (in the presence of bases). Triphenylmethane is obtained by Friedel-Crafts alkylation with benzene.

The determination of the microbial biomass in soil samples by means of chloroform fumigation extraction takes advantage of the fact that chloroform causes cell lysis.

safety instructions

The fumes of chloroform cause unconsciousness and decrease the sensation of pain. Because of its toxic effects on the heart, liver and other internal organs, chloroform is no longer used as an anesthetic. It is also suspected of being carcinogenic.

Legal provisions

The use of chloroform in food-producing animals is generally prohibited in the European Union according to the EU maximum residue limit regulation for food of animal origin.

Deuterochloroform

Deuterated chloroform[32] (Molecular formula: CDCl3, CAS-No .: 865-49-6), also Deuterochloroform called, is used as a solvent in nuclear magnetic resonance spectroscopy (NMR).

The synthesis takes place by reacting the calcium salt of trichloroacetic acid with heavy water.[33]

The physical properties are slightly different from the non-deuterated compound:[34]

  • Melting point: -64 ° C
  • Boiling point: 60.9 ° C
  • Density: 1,500 g / ml (25 ° C)
  • Refractive index: 1.444 (20 ° C)

literature

  • Franz Hartmann: Contribution to the literature on the effects of chloroform. Ferber, Giessen 1855 (digitized version)
  • M. Rossberg; W. Lendle; G. Pfleiderer, A. Tögel; T.R. Torkelson, K.K. Bag: Chloromethanes, in: Ullmann's Encyclopedia of Technical Chemistry, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 2012; doi: 10.1002 / 14356007.a06_233.pub3.
  • Albert Faulconer, Thomas Edward Keys: Chloroform. In: Foundations of Anesthesiology. 2 volumes, Charles C Thomas, Springfield (Illinois) 1965, Volume 1, pp. 442-481.

Individual evidence

  1. abcdefGHijkEntry on trichloromethane in the GESTIS substance database of the IFA, accessed on November 12, 2017 (JavaScript required).
  2. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics. 90th edition. (Internet Version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Dipole Moments, Pp. 9-58.
  3. ↑ Data sheet chloroform at Sigma-Aldrich, accessed on July 19, 2010 (PDF). Template: Sigma-Aldrich / Name not specified Template: Sigma-Aldrich / Access not specified
  4. ↑ Entry on chloroform im Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling.
  5. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (Search for 67-66-3 or. chloroform), accessed November 2, 2015.
  6. ↑ G. Myhre, D. Shindell et al .: Climate Change 2013: The Physical Science Basis. Working Group I contribution to the IPCC Fifth Assessment Report. Ed .: Intergovernmental Panel on Climate Change. 2013, Chapter 8: Anthropogenic and Natural Radiative Forcing, pp. 24-39; Table 8.SM.16 (PDF).
  7. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics. 90th edition. (Internet Version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, Pp. 5-19.
  8. ↑ Chloroform in the Notable Names Database
  9. ↑ Justus Liebig: About the compounds which arise from the action of chlorine on alcohol, ether, oil-forming gas and spirit. In: Annals of Pharmacy. Volume 1, 1832, pp. 182-230 (digitized in the Google book search).
  10. ↑ Jean-Baptiste-André Dumas: Research relative à l’action du chlore sur l’alcool. In: L’Institute. Journal général des société et travaux scientifiques des la France et l’étranger. Volume 2, (April 5) 1834, pp. 106-108.
  11. ↑ Jean-Baptiste-André Dumas: Investigation into the effect of chlorine on alcohol. In: Annals of Physics and Chemistry. New series, Volume 31, 1834, pp. 650-673 (digitized on Gallica).
  12. ↑ Albert Faulconer, Thomas Edward Keys: Chloroform. In: Foundations of Anesthesiology. 2 volumes, Charles C Thomas, Springfield (Illinois) 1965, Volume 1, pp. 442-481, here: pp. 442 f., 455-462.
  13. ↑ J. Y. Simpson: On a new anesthetic agent, more efficient than sulfuric ether. In: Lancet. Volume 2, (November 20) 1847, p. 549 f. (Digitized in the Google book search).
  14. ↑ Ray J. Defalque, Amos J. Wright: The Discovery of Chloroform: Has David Waldie's Role Been Exaggerated? In: Anesthesiology. Volume 114, No. 4, 2011, pp. 1004-1005, doi: 10.1097 / ALN.0b013e31820ca94c.
  15. ↑ www.annethousemuseum: to David Waldie.
  16. ↑ Michael Heck, Michael Fresenius: Anesthesiology revision course. Preparation for the anesthesiological specialist examination and the European diploma in anesthesiology. 3rd, completely revised edition. Springer, Berlin / Heidelberg / New York and others 2001, ISBN 3-540-67331-8, p. 803.
  17. WDR1 - due date November 9, 2007 - 160 years ago: First delivery with chloroform anesthesia. Retrieved November 29, 2017.
  18. Homepage Dortmund Clinic General information on the history of anesthesia. Retrieved November 29, 2017.
  19. ↑ Rudolf Frey, Otto Mayrhofer, with the support of Thomas E. Keys and John S. Lundy: Important dates from the history of anesthesia. In: R. Frey, Werner Hügin, O. Mayrhofer (Eds.): Textbook of anesthesiology and resuscitation. Springer, Heidelberg / Basel / Vienna 1955; 2nd, revised and expanded edition. With the collaboration of H. Benzer. Springer, Berlin / Heidelberg / New York 1971, ISBN 3-540-05196-1, pp. 13–16, here: p. 14.
  20. ↑ Otto Mayrhofer: Thoughts on the 150th birthday of anesthesia. In: The anesthesiologist. Volume 45, 1996, pp. 881-883, here: p. 881.
  21. ↑ Christoph Weißer: Chloroform. In: Werner E. Gerabek, Bernhard D. Haage, Gundolf Keil, Wolfgang Wegner (eds.): Encyclopedia of Medical History. De Gruyter, Berlin 2005, ISBN 3-11-015714-4, p. 257.
  22. ↑ Otto Mayrhofer: Thoughts on the 150th birthday of anesthesia. In: The anesthesiologist. Volume 45, 1996, pp. 881-883, here: pp. 882 f.
  23. ↑ Pollutant Lexicon: Trichloromethane (Chloroform) (Memento of the original from April 15, 2018 in Internet Archive) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.@ 1 @ 2 Template: Webachiv / IABot / www.schadstoff-lexikon.de, accessed on April 7, 2018.
  24. ↑ Sigma-Aldrich: Chloroform.
  25. ↑ Chemgapedia: Synthesis of trichloromethane.
  26. ↑ Stull, D.R .: Vapor Pressure of Pure Substances. Organic and Inorganic Compounds in Ind. Eng. Chem. 39 (1947), pp. 517-540, doi: 10.1021 / ie50448a022.
  27. abR. M. Stephenson: Mutual Solubilities: Water-Ketones, Water-Ethers, and Water-Gasoline-Alcohols in J. Chem. Eng. Data 37 (1992), pp. 80-95, doi: 10.1021 / je00005a024.
  28. abI. M. Smallwood: Handbook of organic solvent properties. Arnold, London 1996, ISBN 0-340-64578-4, pp. 142-143.
  29. Lutz Roth, Ursula Weller Hazardous chemical reactions ISBN 3-609-73090-0 ecomed safety; 2005
  30. ^ Entry "Chloroform" in the Lexicon of Entire Technology (1905)
  31. ↑ Entry on isonitrile. In: Römpp Online. Georg Thieme Verlag, accessed on August 19, 2016.
  32. ↑ External identifiers or database links for deuterochloroform: CAS number: 865-49-6, EC number: 212-742-4, ECHA InfoCard: 100.011.585, PubChem: 71583, ChemSpider: 64654, Wikidata: Q1032539.
  33. ^ Preparation of chloroform-d, on prepchem.com.
  34. ↑ Data sheet Chloroform-d at Sigma-Aldrich, accessed on March 7, 2018 (PDF). Template: Sigma-Aldrich / not specified

Web links