etilen br2

By Admin 15/09/2023 0

From Wikipedia, the không tính phí encyclopedia

Bạn đang xem: etilen br2

1,2-Dibromoethane
Skeletal formula of 1,2-dibromoethane
Skeletal formula of 1,2-dibromoethane
Skeletal formula of 1,2-dibromoethane with all explicit hydrogens added
Skeletal formula of 1,2-dibromoethane with all explicit hydrogens added
Spacefill model of 1,2-dibromoethane
Names
Preferred IUPAC name

1,2-Dibromoethane[1]

Other names
  • Ethylene dibromide[1]
  • Ethylene bromide[2]
  • Glycol bromide[2]
  • Di(bromomethyl)
Identifiers

CAS Number
  • 106-93-4 check

3D model (JSmol)
  • Interactive image
Abbreviations EDB[citation needed]

Beilstein Reference

 605266
ChEBI
  • CHEBI:28534 check
ChEMBL
  • ChEMBL452370 check
ChemSpider
  • 7551 check
ECHA InfoCard 100.003.132 Edit this at Wikidata
EC Number
  • 203-444-5
KEGG
  • C11088 check
MeSH Ethylene+Dibromide

PubChem CID
  • 7839
RTECS number
  • KH9275000
UNII
  • 1N41638RNO ☒
UN number 1605

CompTox Dashboard (EPA)
  • DTXSID3020415 Edit this at Wikidata

InChI

  • InChI=1S/C2H4Br2/c3-1-2-4/h1-2H2 check

    Key: PAAZPARNPHGIKF-UHFFFAOYSA-N check

SMILES

  • BrCCBr

Properties

Chemical formula

 C2H4Br2
Molar mass 187.862 g·mol−1
Appearance Colorless liquid
Odor faintly sweet[2]
Density 2.18 g mL−1
Melting point 9.4 to tát 10.2 °C; 48.8 to tát 50.3 °F; 282.5 to tát 283.3 K
Boiling point 129 to tát 133 °C; 264 to tát 271 °F; 402 to tát 406 K

Solubility in water

 0.4% (20 °C)[2]
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[2]
GHS labelling:

Pictograms

 GHS06: Toxic GHS08: Health hazard GHS09: Environmental hazard

Signal word

Xem thêm: sinh tháng 1 là cung gì

 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)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code

3

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)[3]

LCLo (lowest published)

 200 ppm (rat, 8 hr)
400 ppm (guinea pig, 3 hr)[3]
NIOSH (US health exposure limits):

PEL (Permissible)

 TWA đôi mươi 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 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 check☒ ?)

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, 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]

Preparation and use[edit]

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 tát 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 tát 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 tát some fire retardants.[4]

In organic synthesis, 1,2-dibromoethane is used as a source of bromine to tát brominate carbanions and to tát 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 tát the substrate.[10]

Health effects[edit]

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 tát 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 tát cause birth defects in humans. Swallowing has caused death at 40ml doses.[8]

Xem thêm: hai đứa trẻ thạch lam

References[edit]

  1. ^ a b "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. năm trước. p. 657. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ a b c d e f g h NIOSH Pocket Guide to tát Chemical Hazards. "#0270". National Institute for Occupational Safety and Health (NIOSH).
  3. ^ a b "Ethylene dibromide". Immediately Dangerous to tát Life or Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  4. ^ 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.
  5. ^ a b c "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.
  8. ^ a b "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".

External links[edit]

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