1,2-Dibromoethane

1,2-Dibromoethane
Skeletal formula of 1,2-dibromoethane	Skeletal formula of 1,2-dibromoethane with all explicit hydrogens added
Names
	Preferred IUPAC name 1,2-Dibromoethane
	Other names Ethylene dibromide; Ethylene bromide; Glycol bromide; Di(bromomethyl);
Identifiers
CAS Number	106-93-4 ;
3D model (JSmol)	Interactive image;
Abbreviations	EDB[citation needed]
Beilstein Reference	605266
ChEBI	CHEBI:28534 ;
ChEMBL	ChEMBL452370 ;
ChemSpider	7551 ;
ECHA InfoCard	100.003.132
EC Number	203-444-5;
KEGG	C11088 ;
MeSH	Ethylene+Dibromide
PubChem CID	7839;
RTECS number	KH9275000;
UNII	1N41638RNO ;
UN number	1605
CompTox Dashboard (EPA)	DTXSID3020415 ;
	InChI InChI=1S/C2H4Br2/c3-1-2-4/h1-2H2 Key: PAAZPARNPHGIKF-UHFFFAOYSA-N ;
	SMILES BrCCBr;
Properties
Chemical formula	C2H4Br2
Molar mass	187.862 g·mol−1
Appearance	Colorless liquid
Odor	faintly 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
Heat capacity (C)	134.7 J K−1 mol−1
Std molar; entropy (S⦵298)	223.30 J K−1 mol−1
Std enthalpy of; combustion (ΔcH⦵298)	−1.2419–−1.2387 MJ mol−1
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	carcinogen
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H301, H311, H315, H319, H331, H335, H350, H411
Precautionary statements	P261, P273, P280, P301+P310, P305+P351+P338
NFPA 704 (fire diamond)	3 0 0
Flash point	104 °C (219 °F; 377 K)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	55.0 mg kg−1 (oral, rabbit); 79.0 mg kg−1 (oral, chicken); 110.0 mg kg−1 (oral, guinea pig); 130.0 mg kg−1 (oral, quail); 300.0 mg kg−1 (dermal, rabbit);
LC50 (median concentration)	1831 ppm (rat, 30 min); 691 ppm (rat, 1 hr)
LCLo (lowest published)	200 ppm (rat, 8 hr); 400 ppm (guinea pig, 3 hr)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 20 ppm C 30 ppm 50 ppm [5-minute maximum peak]
REL (Recommended)	Ca TWA 0.045 ppm C 0.13 ppm [15-minute]
IDLH (Immediate danger)	Ca [100 ppm]
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). verify (what is ?) Infobox references

1,2-Dibromoethane, also known as ethylene dibromide (EDB), is an organobromine compound with the chemical formula C
₂H
₄Br
₂. Although trace amounts occur naturally in the ocean, where it is probably formed by algae and kelp, substantial amounts are produced industrially. It is a dense colorless liquid with a faint, sweet odor, detectable at 10 ppm. It is a widely used and sometimes-controversial fumigant.^[4] The combustion of 1,2-dibromoethane produces hydrogen bromide gas that is significantly corrosive.^[5]

Preparation and use

It is produced by the reaction of ethylene gas with bromine,^[6] in a classic halogen addition reaction:

CH₂=CH₂ + Br₂ → BrCH₂–CH₂Br

Historically, 1,2-dibromoethane was used as a component in anti-knock additives in leaded fuels. It reacts with lead residues to generate volatile lead bromides, thereby preventing fouling of the engine with lead deposits.^[7]

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).^[4] 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, and for control of moths in beehives.^[8]

Reagent

1,2-Dibromoethane has wider applications in the preparation of other organic compounds including those carrying modified diazocine rings^[9] and vinyl bromide that is a precursor to some fire retardants.^[4]

In organic synthesis, 1,2-dibromoethane is used to brominate carbanions and to activate magnesium for certain Grignard reagents. In the latter process, 1,2-dibromoethane reacts with magnesium, producing ethylene and magnesium bromide, which are innocuous, exposing a more active portion of the magnesium particle to the substrate.^[10]

Health effects

1,2-Dibromoethane causes changes in the metabolism and severe destruction of living tissues.^[5] The known empirical LD50 values for 1,2-dibromoethane are 140 mg kg⁻¹ (oral, rat), and 300.0 mg kg⁻¹ (dermal, rabbit).^[5] 1,2-Dibromoethane is a known carcinogen, with pre-1977 exposure levels ranking it as the most carcinogenic substance on the HERP Index.^[11]

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.^[12] 1,2-Dibromoethane is not known to cause birth defects in humans. Swallowing has caused death at 40ml doses.^[8]

References

^ ^a ^b "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 657. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
^ ^a ^b ^c ^d ^e ^f ^g ^h NIOSH Pocket Guide to Chemical Hazards. "#0270". National Institute for Occupational Safety and Health (NIOSH).
^ ^a ^b "Ethylene dibromide". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
^ ^a ^b ^c Yoffe, David; Frim, Ron; Ukeles, Shmuel D.; Dagani, Michael J.; Barda, Henry J.; Benya, Theodore J.; Sanders, David C. (2013). "Bromine Compounds". Ullmann's Encyclopedia of Industrial Chemistry. pp. 1–31. doi:10.1002/14356007.a04_405.pub2. ISBN 978-3-527-30385-4.
^ ^a ^b ^c "Safety Data Sheet for CAS-No.:106-93-4 Ethylene dibromide".
^ "Preparation and purification of 1,2-dibromoethane" (PDF). Synlett. 28: 49–51. 2017.
^ Seyferth, D. (2003). "The Rise and Fall of Tetraethyllead. 2". Organometallics. 22 (25): 5154–5178. doi:10.1021/om030621b.
^ ^a ^b "Toxicological Profile for 1,2-Dibromoethane" (PDF). Archived from the original (PDF) on 2009-11-22. Retrieved 2009-11-22.
^ Hamada, Y.; Mukai. S. (1996). "Synthesis of ethano-Tröger's base, configurationally stable substitute of Tröger's base". Tetrahedron Asymmetry. 7 (9): 2671–2674. doi:10.1016/0957-4166(96)00343-6.
^ Maynard, G. D. (2004). "1,2-Dibromoethane". In Paquette, L. (ed.). Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.rd039. ISBN 0471936235.
^ "Ranking Possible Cancer Hazards from Rodent Carcinogens" (PDF). Archived from the original (PDF) on 2019-06-29.
^ "Toxic Substances Portal – 1,2-Dibromoethane".

External links

[iupac2013-1] "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 657. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.

[PGCH-2] ^ ^a ^b ^c ^d ^e ^f ^g ^h NIOSH Pocket Guide to Chemical Hazards. "#0270". National Institute for Occupational Safety and Health (NIOSH).

[IDLH-3] "Ethylene dibromide". Immediately Dangerous to Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).

[Ullmann-4] Yoffe, David; Frim, Ron; Ukeles, Shmuel D.; Dagani, Michael J.; Barda, Henry J.; Benya, Theodore J.; Sanders, David C. (2013). "Bromine Compounds". Ullmann's Encyclopedia of Industrial Chemistry. pp. 1–31. doi:10.1002/14356007.a04_405.pub2. ISBN 978-3-527-30385-4.

[:0-5] "Safety Data Sheet for CAS-No.:106-93-4 Ethylene dibromide".

[6] "Preparation and purification of 1,2-dibromoethane" (PDF). Synlett. 28: 49–51. 2017.

[7] Seyferth, D. (2003). "The Rise and Fall of Tetraethyllead. 2". Organometallics. 22 (25): 5154–5178. doi:10.1021/om030621b.

[www.atsdr.cdc.gov-8] "Toxicological Profile for 1,2-Dibromoethane" (PDF). Archived from the original (PDF) on 2009-11-22. Retrieved 2009-11-22.

[9] Hamada, Y.; Mukai. S. (1996). "Synthesis of ethano-Tröger's base, configurationally stable substitute of Tröger's base". Tetrahedron Asymmetry. 7 (9): 2671–2674. doi:10.1016/0957-4166(96)00343-6.

[10] Maynard, G. D. (2004). "1,2-Dibromoethane". In Paquette, L. (ed.). Encyclopedia of Reagents for Organic Synthesis. New York: J. Wiley & Sons. doi:10.1002/047084289X.rd039. ISBN 0471936235.

[11] "Ranking Possible Cancer Hazards from Rodent Carcinogens" (PDF). Archived from the original (PDF) on 2019-06-29.

[12] "Toxic Substances Portal – 1,2-Dibromoethane".

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