Dibromodifluoromethane

Structural formula
General
Surname	Dibromodifluoromethane
other names	Difluorodibromomethane H 1202 R-12B2
Molecular formula	CBr 2 F 2
Brief description	colorless liquid
External identifiers / databases
CAS number 75-61-6 EC number 200-885-5 ECHA InfoCard 100,000,805 PubChem 6382 Wikidata Q905027
properties
Molar mass	209.82 g mol −1
Physical state	liquid
density	2.3063 g cm −3 (15 ° C)
Melting point	−110 ° C
boiling point	24.5 ° C
Vapor pressure	920 mbar (20 ° C)
solubility	practically insoluble in water soluble in methanol and ether
Refractive index	1.398 (20 ° C)
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 420 P: no P-phrases
MAK	Switzerland: 100 ml m −3 or 860 mg m −3
Global warming potential	280 (based on 100 years)
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Dibromodifluoromethane is a chemical compound from the group of halogenated hydrocarbons .

Extraction and presentation

Dibromodifluoromethane can be obtained by the vapor phase bromination of difluoromethane .

It is also formed during the fluorination of tetrabromomethane .

Dibromodifluoromethane can be produced in 83% yield as the only product by fluorination of tetrabromomethane with iodine pentafluoride , as the main product (relative yield 76%) by fluorination with bromine (III) fluoride and as a by-product (relative yield 16%) by fluorination of tetraiodomethane with iodine pentafluoride . The fluorination of tetrabromomethane with titanium (IV) fluoride forms dibromodifluoromethane in low yield as a mixture with bromotrifluoromethane . In addition, dibromodifluoromethane is formed in high yield (81%) by heating silver bromodifluoroacetate with bromine.

${\displaystyle {\ce {CBr4 + IF5 -> CBr2F2 + CBr3F + CBrF3 + CF4}}}$

${\displaystyle {\ce {CBrF2CO2Ag + Br2 -> CBr2F2 + CO2 + AgBr}}}$

properties

Dibromodifluoromethane is a very volatile, colorless liquid that is practically insoluble in water. It decomposes when heated and has an ozone depletion potential of 1.25.

use

Dibromodifluoromethane is used as an extinguishing agent (for example in military aircraft) and as an intermediate in the manufacture of dyes, pharmaceuticals and quaternary ammonium compounds. The compound is not currently covered by the Montreal Protocol , but the sources of the compound found in the environment are increasingly being investigated.

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on dibromodifluoromethane in the GESTIS substance database of the IFA , accessed on January 8, 2018(JavaScript required) .
2. ↑ Terry Hills: Organic Chemistry . Lotus Press, 2004, ISBN 81-89093-51-7 , pp. 60 ( limited preview in Google Book search).
3. ↑ ^{a b} Data sheet dibromodifluoromethane, ≥95.0% (GC) from Sigma-Aldrich , accessed on February 4, 2018 ( PDF ).
4. ↑ Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 75-61-6 or dibromodifluoromethane ), accessed on November 2, 2015.
5. ↑ G. Myhre, D. Shindell et al .: Climate Change 2013: The Physical Science Basis . Working Group I contribution to the IPCC Fifth Assessment Report. Ed .: Intergovernmental Panel on Climate Change . 2013, Chapter 8: Anthropogenic and Natural Radiative Forcing, pp. 24-39; Table 8.SM.16 ( PDF ).
6. ↑ ^{a b} Entry on dibromodifluoromethane in the Hazardous Substances Data Bank , accessed on March 10, 2013.
7. ^ Alan Roy Katritzky, Otto Meth-Cohn, Thomas Lonsdale Gilchrist, Charles Wayne Rees: Comprehensive Organic Functional Group Transformations: Carbon with Three Or ... Elsevier, 1995, ISBN 0-08-042704-9 , p. 226 ( limited preview in Google Book search).
8. ^ Alan R. Katritzky, Thomas L. Gilchrist, Otto Meth-Cohn, Charles Wayne Rees: Comprehensive Organic Functional Group Transformations . Elsevier, 1995, ISBN 978-0-08-042704-1 , pp. 226 ( limited preview in Google Book search).
9. ↑ ^{a b} unep.fr: UNEP DTIE OzonAction Branch: Information resources , accessed on May 28, 2015
10. ↑ potential Ozone Depleting Substances Uses and Alternatives in the Nordic Countries . Nordic Council of Ministers, 2005, ISBN 978-92-893-1252-3 , pp. 41 ( limited preview in Google Book search).
11. ↑ Handbook For The Montreal Protocol On Substances That Deplete The Ozone Layer . UNEP / Earthprint, 2006, ISBN 978-92-807-2770-8 , pp. 479 ( limited preview in Google Book search).