1,2-dichloropropane
Structural formula | ||||||||||||||||
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Simplified structural formula without stereochemistry | ||||||||||||||||
General | ||||||||||||||||
Surname | 1,2-dichloropropane | |||||||||||||||
other names |
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Molecular formula | C 3 H 6 Cl 2 | |||||||||||||||
Brief description |
colorless liquid with a sweet odor |
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properties | ||||||||||||||||
Molar mass | 112.99 g mol −1 | |||||||||||||||
Physical state |
liquid |
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density |
1.16 g cm −3 |
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Melting point |
−100.4 ° C |
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boiling point |
96 ° C |
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Vapor pressure |
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solubility |
heavy in water (2.7 g l −1 at 20 ° C) |
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Refractive index |
1.4394 (20 ° C) |
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safety instructions | ||||||||||||||||
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MAK |
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Thermodynamic properties | ||||||||||||||||
ΔH f 0 |
−198.8 kJ / mol |
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As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C |
1,2-dichloropropane is a clear, colorless to yellowish, flammable liquid with a sweet, chloroform- like odor. It was widely used as a solvent in many commodity chemicals and is a starting material for organic synthesis . If it gets into the body or on the skin, it can cause kidney and liver damage. Since it is only broken down by special bacteria, it accumulates in the soil and poses a problem in groundwater .
Presentation and extraction
Carl Schorlemmer was the first to report on the production of 1,2-dichloropropane in 1869 when he exposed a mixture of the gases chlorine and propane in a glass container to sunlight. Even today it is a main product in the industrial chlorination of propane. The synthesis takes place via the monochlorinated propanes, which in turn are immediately converted to the dichlorinated propanes.
properties
Stereoisomerism
1,2-dichloropropane is chiral , i.e. it has a stereocenter. There are thus two enantiomers : ( R ) -1,2-dichloropropane and ( S ) -1,2-dichloropropane. When “1,2-dichloropropane” is spoken of without a prefix , the racemate [1: 1 mixture of ( R ) -1,2-dichloropropane and ( S ) -1,2-dichloropropane] is meant, i.e. ( RS ) -1,2-dichloropropane.
Safety-related parameters
1,2-dichloropropane forms highly flammable vapor-air mixtures. The compound has a flash point of 15 ° C. The explosion range is between 3.1% by volume (146 g / m 3 ) as the lower explosion limit (LEL) and 14.5% by volume (690 g / m 3 ) as the upper explosion limit (UEL). The lower explosion point is 7 ° C. The ignition temperature is 555 ° C. The substance therefore falls into temperature class T1.
Use and ecology
DCP was widely used as a solvent for oils , waxes , resins , adhesives , degreasers , pesticides and varnishes , but has been replaced by other substances. It is still a raw material for organic synthesis.
Although 1,2-dichloropropane has not been approved in Germany since 1987 because of its low effectiveness for container fumigation, the substance is still found today in soils and groundwater due to its high stability, and limit values are sometimes exceeded. As a result, several wells and entire waterworks had to be shut down in the Pinneberg district and activated carbon filter systems had to be built. The half-life of DCP in groundwater is between 6 months and 2 years.
Anaerobic bacteria of the genus Dehalococcoides are able to break down propylene dichloride.
safety instructions
The Committee for Risk Assessment (RAC) of the European Chemicals Agency (ECHA) decided in June 2014 that 1,2-dichloropropane should be classified as Carc 1B. The scientific justification has yet to be implemented in applicable law by the EU Commission.
literature
- Beilstein Syst. No. 10: H, p. 105 .
Individual evidence
- ↑ a b c d e f g h i j k l m n o p Entry on 1,2-dichloropropane in the GESTIS substance database of the IFA , accessed on November 24, 2019(JavaScript required) .
- ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-158.
- ↑ Entry on 1,2-dichloropropane in the 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 .
- ↑ Swiss Accident Insurance Fund (Suva): Limits - Current MAK and BAT values (search for 78-87-5 or 1,2-dichloropropane ), accessed on November 2, 2015.
- ↑ 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. 5-24.
- ↑ E Fiaccadori et al .: Acute renal and hepatic failure due to accidental percutaneous absorption of 1,2-dichloropropane contained in a commercial paint fixative . In: Nephrol Dial Transplant . 2003; 18: pp. 219-220.
- ↑ a b c Chemsafe database for safety-related parameters in explosion protection, PTB Braunschweig / BAM Berlin, accessed on November 24, 2019.
- ↑ Wolfgang Wolters: Investigations on pesticides in the groundwater of Schleswig-Holstein ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.
- ↑ Eco-USA: 1,2-dichloropropane ( Memento of the original from January 23, 2016 in the 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. , accessed January 23, 2016.
- ↑ Ritalahti KM and Loffler FE: Populations implicated in anaerobic reductive dechlorination of 1,2-dichloropropane in highly enriched bacterial communities. Appl Environ Microbiol. 70/7/ 2004 . Pp. 4088-4095, PMID 15240287 .
- ↑ RAC statement on dichloropropane of June 4, 2014 , accessed on April 1, 2015.