Dibromomethane

Source: Wikipedia, the free encyclopedia.
Dibromomethane
Spacefill model for dibromomethane
Names
Preferred IUPAC name
Dibromomethane[1]
Other names
  • Methyl dibromide
  • Methylene bromide
  • Methylene dibromide
  • Refrigerant-30B2[citation needed]
Identifiers
3D model (
JSmol
)
Abbreviations
969143
ChEBI
ChemSpider
ECHA InfoCard
 100.000.750 Edit this at Wikidata
EC Number
  • 200-824-2
25649
MeSH methylene+bromide
RTECS number
  • PA7350000
UNII
UN number 2664
  • InChI=1S/CH2Br2/c2-1-3/h1H2 checkY
    Key: FJBFPHVGVWTDIP-UHFFFAOYSA-N checkY
  • BrCBr
Properties
CH2Br2
Molar mass 173.835 g·mol−1
Appearance Colorless to yellow liquid
Density 2.477 g⋅mL−1
Melting point −52.70 °C; −62.86 °F; 220.45 K
Boiling point 96 to 98 °C; 205 to 208 °F; 369 to 371 K
12.5 g⋅L−1 (at 20 °C)
Vapor pressure 4.65 kPa (at 20.0 °C)
9.3 μmol⋅Pa−1⋅kg−1
−65.10·10−6⋅cm3/mol
1.541
Thermochemistry
104.1 J⋅K−1⋅mol−1
Hazards
GHS labelling:
GHS07: Exclamation mark
Warning
H332, H412
P273
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 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
2
0
0
Lethal dose or concentration (LD, LC):
  • 1 g⋅kg−1 (oral, rabbit)
  • 3.738 g⋅kg−1 (subcutaneous, mouse)
  • >4 g⋅kg−1 (dermal, rabbit)
Related compounds
Related alkanes
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Dibromomethane or methylene bromide, or methylene dibromide is a

organic solvents
. It is a colorless liquid.

Preparation

Dibromomethane is prepared commercially from dichloromethane via bromochloromethane:

6 CH2Cl2 + 3 Br2 + 2 Al → 6 CH2BrCl + 2 AlCl3
CH2Cl2 + HBr → CH2BrCl + HCl

The latter route requires

aluminium trichloride as a catalyst.[2]
The bromochloromethane product from either reaction can further react in a similar manner:

6 CH2BrCl + 3 Br2 + 2 Al → 6 CH2Br2 + 2 AlCl3
CH2BrCl + HBr → CH2Br2 + HCl

In the laboratory, it is prepared from bromoform using sodium arsenite and sodium hydroxide:[3]

CHBr3 + Na3AsO3 + NaOH → CH2Br2 + Na3AsO4 + NaBr


Another way is to prepare it from diiodomethane and bromine.

Uses

Dibromomethane is used as a

catechols to their methylenedioxy
derivatives.

Natural occurrence

It is naturally produced by marine

hydroxyl
radicals. The estimated half life of this reaction is 213 days.

References
  1. ^ "methylene bromide - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 25 March 2005. Identification. Retrieved 18 June 2012.
  2. ^
    ISBN 978-3527306732
    .
  3. doi:10.15227/orgsyn.009.0056
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Dibromomethane&oldid=1212518091"