1,2-Dibromotetrachloroethane

1,2-Dibromotetrachloroethane

Names
IUPAC name 1,2-dibromo-1,1,2,2-tetrachloroethane
Other names dibromotetrachloroethane, sym-Dibromotetrachloroethane, DBTCE, Bromure de chloréthose ("bromide of chlorethose")
Identifiers
CAS Number	630-25-1 Y
3D model (JSmol)	Interactive image
ChemSpider	62634
ECHA InfoCard	100.010.125
EC Number	211-136-7
PubChem CID	69426
UNII	0SGG217EFR
CompTox Dashboard (EPA)	DTXSID20212209
InChI InChI=1S/C2Br2Cl4/c3-1(5,6)2(4,7)8 Key: WJUKOGPNGRUXMG-UHFFFAOYSA-N
SMILES ClC(Cl)(Br)C(Cl)(Cl)Br
Properties
Chemical formula	C2Br2Cl4
Molar mass	325.63 g·mol−1
Appearance	Crystalline solid
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H302, H315, H319, H335
Precautionary statements	P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

1,2-Dibromotetrachloroethane (DBTCE) is an organohalide with the chemical formula C₂Br₂Cl₄. It is a crystalline solid that emits lachrymatory (tear-producing) vapours. Dibromotetrachloroethane can be used as a fungicide, flame retardant and a source for bromine in the laboratory. Because the 1,1-dibromotetrachloroethane isomer is rare, 1,2-dibromotetrachloroethane is frequently referred to as simply dibromotetrachloroethane.

Reactions and synthesis

Dibromotetrachloroethane decomposes to Tetrachloroethylene and bromine when heated. Reacted with potassium sulphide, it gives tetrachloroethylene, potassium bromide and sulphur:

C₂Br₂Cl₄ + K₂S → C₂Cl₄ + S + 2 KBr

Dibromotetrachloroethane, when reacted with aniline at 140 to 150 °C, gives pure tetrachloroethylene.

When reacted with compounds like cyclohexene, 2,2,4-trimethylpentl-ene, 1-hexene, 1-octene, 2-methyl-1-butene and 2,2,4-trimethyl-2-pentene, it yields allylic monobromides via bromination. Dibromotetrachloroethane loses both of its bromine atoms, leaving tetrachloroethylene and hydrogen bromide.

Dibromotetrachloroethane was discovered by the Italian chemist Faustino Malaguti in 1846. Malaguti exposed a mixture of Tetrachloroethylene (then known as chloréthose) and bromine to sunlight. It was named Bromure de chloréthose ("bromide of chlorethose") after its synthesis method. Similar to Malaguti's method, modern synthesis of dibromotetrachloroethane uses bromine dissolved in carbon tetrachloride.