1,2-Dibromoethane, also known as ethylene dibromide (EDB), is an organobromine compound with the chemical formulaC 2H 4Br 2. Although trace amounts occur naturally in the ocean, where it is probably formed by algae and kelp, it is mainly synthetic. It is a dense colorless liquid with a faint, sweet odor, detectable at 10 ppm, and is a widely used and sometimes-controversial fumigant.[4] The combustion of 1,2-dibromoethane produces hydrogen bromide gas that is significantly corrosive.[5]
1,2-Dibromoethane
Skeletal formula of 1,2-dibromoethane
Skeletal formula of 1,2-dibromoethane with all explicit hydrogens added
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]
Pesticideedit
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]
Reagentedit
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 as a source of bromine to brominate carbanions and to activate magnesium for certain Grignard reagents. In the latter process, 1,2-dibromoethane reacts with magnesium, producing ethene and magnesium bromide, and exposes a freshly etched portion of magnesium to the substrate.[10]
Health effectsedit
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]
Referencesedit
^ ab"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. ISBN978-0-85404-182-4.
^ abc"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.
^ ab(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. ISBN0471936235.
^(PDF). Archived from the original (PDF) on 2019-06-29.
dibromoethane, also, known, ethylene, dibromide, organobromine, compound, with, chemical, formula, although, trace, amounts, occur, naturally, ocean, where, probably, formed, algae, kelp, mainly, synthetic, dense, colorless, liquid, with, faint, sweet, odor, d. 1 2 Dibromoethane also known as ethylene dibromide EDB is an organobromine compound with the chemical formula C2 H4 Br2 Although trace amounts occur naturally in the ocean where it is probably formed by algae and kelp it is mainly synthetic It is a dense colorless liquid with a faint sweet odor detectable at 10 ppm and is a widely used and sometimes controversial fumigant 4 The combustion of 1 2 dibromoethane produces hydrogen bromide gas that is significantly corrosive 5 1 2 Dibromoethane Skeletal formula of 1 2 dibromoethane Skeletal formula of 1 2 dibromoethane with all explicit hydrogens addedNamesPreferred IUPAC name 1 2 Dibromoethane 1 Other names Ethylene dibromide 1 Ethylene bromide 2 Glycol bromide 2 Di bromomethyl IdentifiersCAS Number 106 93 4 Y3D model JSmol Interactive imageAbbreviations EDB citation needed Beilstein Reference 605266ChEBI CHEBI 28534 YChEMBL ChEMBL452370 YChemSpider 7551 YECHA InfoCard 100 003 132EC Number 203 444 5KEGG C11088 YMeSH Ethylene DibromidePubChem CID 7839RTECS number KH9275000UNII 1N41638RNO NUN number 1605CompTox Dashboard EPA DTXSID3020415InChI InChI 1S C2H4Br2 c3 1 2 4 h1 2H2 YKey PAAZPARNPHGIKF UHFFFAOYSA N YSMILES BrCCBrPropertiesChemical formula C 2H 4Br 2Molar mass 187 862 g mol 1Appearance Colorless liquidOdor faintly sweet 2 Density 2 18 g mL 1Melting point 9 4 to 10 2 C 48 8 to 50 3 F 282 5 to 283 3 KBoiling point 129 to 133 C 264 to 271 F 402 to 406 KSolubility in water 0 4 20 C 2 log P 2 024Vapor pressure 1 56 kPaHenry s lawconstant kH 14 mmol Pa kg 1Refractive index nD 1 539ThermochemistryHeat capacity C 134 7 J K 1 mol 1Std molarentropy S 298 223 30 J K 1 mol 1Std enthalpy ofcombustion DcH 298 1 2419 1 2387 MJ mol 1HazardsOccupational safety and health OHS OSH Main hazards carcinogen 2 GHS labelling PictogramsSignal word DangerHazard statements H301 H311 H315 H319 H331 H335 H350 H411Precautionary statements P261 P273 P280 P301 P310 P305 P351 P338NFPA 704 fire diamond 300Flash 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 3 LCLo lowest published 200 ppm rat 8 hr 400 ppm guinea pig 3 hr 3 NIOSH US health exposure limits PEL Permissible TWA 20 ppm C 30 ppm 50 ppm 5 minute maximum peak 2 REL Recommended Ca TWA 0 045 ppm C 0 13 ppm 15 minute 2 IDLH Immediate danger Ca 100 ppm 2 Related compoundsRelated alkanes DibromomethaneBromoformTetrabromomethane1 1 DibromoethaneTetrabromoethane1 2 Dibromopropane1 3 Dibromopropane1 2 3 TribromopropaneExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Preparation and use 1 1 Pesticide 1 2 Reagent 2 Health effects 3 References 4 External linksPreparation and use editIt is produced by the reaction of ethylene gas with bromine 6 in a classic halogen addition reaction CH2 CH2 Br2 BrCH2 CH2BrHistorically 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 edit 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 edit 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 as a source of bromine to brominate carbanions and to activate magnesium for certain Grignard reagents In the latter process 1 2 dibromoethane reacts with magnesium producing ethene and magnesium bromide and exposes a freshly etched portion of magnesium to the substrate 10 Health effects edit1 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 edit 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 Dagani M J Barda H J Benya T J Sanders D C Bromine Compounds Ullmann s Encyclopedia of Industrial Chemistry Weinheim Wiley VCH doi 10 1002 14356007 a04 405 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 Troger s base configurationally stable substitute of Troger 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 amp 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 editNational Pollutant Inventory 1 2 Dibromoethane Fact Sheet Congressional Research Service CRS Reports regarding Ethylene Dibromide ATSDR ToxFAQs CDC NIOSH Pocket Guide to Chemical Hazards Retrieved from https en wikipedia org w index php title 1 2 Dibromoethane amp oldid 1182249950, wikipedia, wiki, book, books, library,
