1,2-Dibromoethane

1,2-Dibromoethane

Names
IUPAC name 1,2-Dibromoethane
Other names Ethylene bromide Ethylene dibromide Glycol bromide
Identifiers
CAS Number	106-93-4 Y
Abbreviations	EDB
Beilstein Reference	605266
ChEBI	CHEBI:28534 Y
ChEMBL	ChEMBL452370 Y
ChemSpider	7551 Y
EC Number	203-444-5
Jmol 3D model	Interactive image
KEGG	C11088 Y
MeSH	Ethylene+Dibromide
PubChem	7839
RTECS number	KH9275000
UN number	1605
InChI InChI=1S/C2H4Br2/c3-1-2-4/h1-2H2 Y Key: PAAZPARNPHGIKF-UHFFFAOYSA-N Y
SMILES BrCCBr
Properties
Chemical formula	C2H4Br2
Molar mass	187.86 g·mol−1
Appearance	Colorless liquid
Odor	sweet
Density	2.18 g mL−1
Melting point	9.4 to 10.2 °C; 48.8 to 50.3 °F; 282.5 to 283.3 K
Boiling point	129 to 133 °C; 264 to 271 °F; 402 to 406 K
Solubility in water	0.4% (20 °C)
log P	2.024
Vapor pressure	1.56 kPa
Henry's law constant (kH)	14 μmol Pa kg−1
Refractive index (nD)	1.539
Thermochemistry
Specific heat capacity (C)	134.7 J K−1 mol−1
Std molar entropy (So298)	223.30 J K−1 mol−1
Std enthalpy of combustion (ΔcHo298)	−1.2419–−1.2387 MJ mol−1
Vapor pressure	{{{value}}}
Related compounds
Related alkanes	Dibromomethane Bromoform Tetrabromomethane 1,1-Dibromoethane Tetrabromoethane 1,2-Dibromopropane 1,3-Dibromopropane 1,2,3-Tribromopropane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

1,2-Dibromoethane, also known as ethylene dibromide (EDB), is the organobromine compound with the chemical formula (CH₂Br)₂. Although trace amounts occur naturally in the ocean, where it is formed probably by algae and kelp, it is mainly synthetic. It is a colorless liquid with a sweet odor, detectable at 10 ppm, is a widely used and sometimes-controversial fumigant.

Preparation and use

It is produced by the reaction of ethylene with bromine, in a classic halogen addition reaction:

CH₂=CH₂ + Br₂ → BrCH₂CH₂Br

Historically, 1,2-dibromoethane was used as an anti-knock additive in leaded fuels. It reacts with lead residues to generate volatile lead bromides, thereby preventing fouling of the engine.

Pesticide

It has been used as a pesticide in soil and on various crops. The applications were initiated after the forced retirement of 1,2-dibromo-3-chloropropane (DBCP). Most of these uses have been stopped in the U.S. It continues to be used as a fumigant for treatment of logs for termites and beetles, for control of moths in beehives.

Reagent

Ethylene bromide has wider applications in the preparation of other organic compounds. It is used to make vinyl bromide, a precursor to some fire retardants.

In the laboratory, 1,2-dibromoethane is used in organic synthesis as a source of bromine, e.g., to brominate carbanions and to activate magnesium for certain Grignard reagents. In the latter process, the 1,2-dibromoethane is converted to ethylene and magnesium bromide, exposing a freshly etched portion of magnesium to the substrate.

Health effects

The effects on people of breathing high levels are not known, but animal studies with short-term exposures to high levels caused depression and collapse, indicating effects on the brain. Changes in the brain and behavior were also seen in young rats whose male parents had breathed 1,2-dibromoethane, and birth defects were observed in the young of animals that were exposed while pregnant. 1,2-Dibromoethane is not known to cause birth defects in humans. Swallowing has caused death at 40 mL doses

It is a known carcinogen, with pre-1977 exposure levels ranking it as the most carcinogenic substance on the HERP Index.

External links

• National Pollutant Inventory 1,2-Dibromoethane Fact Sheet
• Congressional Research Service (CRS) Reports regarding Ethylene Dibromide
• ATSDR ToxFAQs
• CDC - NIOSH Pocket Guide to Chemical Hazards