Difference between revisions of "1,1-Dichloroethene"

Latest revision as of 09:59, 20 September 2010

1,1-Dichloroethene
Structural formula	Ball-and-stick model
IUPAC name 1,1-Dichloroethene
Other names 1,1-Dichloroethylene 1,1-DCE vinylidene chloride vinylidene dichloride
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number	75-35-4 Y
ChemSpider	6126
SMILES	Script error: No such module "collapsible list".
style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula	C2H2Cl2
Molar mass	96.94 g/mol
Density	1.213 g/cm³
Melting point	-122 °C
Boiling point	32 °C
Dipole moment	2.3 D
style="background: #F8EABA; text-align: center;" colspan="2" | Hazards
NFPA 704	75px 4 2 2
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

1,1-Dichloroethene, commonly called 1,1-dichloroethylene or 1,1-DCE, is an organochloride with the molecular formula C₂H₂Cl₂. It is a colorless liquid with a sharp odor. Like most chlorocarbons, it is poorly soluble in water, but soluble in organic solvents. 1,1-DCE was the precursor to the original cling-wrap for food, but this application has been phased out.

Production

1,1-DCE is produced by dehydrochlorination of 1,1,2-trichloroethane, a relatively unwanted byproduct in the production of 1,1,1-trichloroethane and 1,2-dichloroethane. The conversion involves a base-catalyzed reaction:

Cl₂CHCH₂Cl + NaOH → Cl₂C=CH₂ + NaCl + H₂O

The gas phase reaction, without the base, would be more desirable but is less selective.^[1]

Applications

1,1-DCE is mainly used as a comonomer in the polymerization of vinyl chloride, acrylonitrile, and acrylates. It is also used in semiconductor device fabrication for growing high purity silicon dioxide (SiO₂) films.

Polyvinylidene chloride

As with many other alkenes, 1,1-DCE can be polymerised to form polyvinylidene chloride. A very widely used product, cling wrap, or Saran was made from this polymer. During the 1990s research suggested that, in common with many chlorinated carbon compounds, Saran posed a possible danger to health by leaching, especially on exposure to food in microwave ovens. Since 2004, therefore cling wrap's formulation has changed to a form of polythene.

Safety

The health effects from exposure to 1,1-DCE are primarily on the central nervous system, including symptoms of sedation, inebriation, convulsions, spasms, and unconsciousness at high concentrations.^[2]

See also

• 1,2-Dichloroethene
• 1,1-Dichloroethane

References

1. ↑ Manfred Rossberg, Wilhelm Lendle, Gerhard Pfleiderer, Adolf Tögel, Eberhard-Ludwig Dreher, Ernst Langer, Heinz Rassaerts, Peter Kleinschmidt, Heinz Strack, Richard Cook, Uwe Beck, Karl-August Lipper, Theodore R. Torkelson, Eckhard Löser, Klaus K. Beutel, Trevor Mann “Chlorinated Hydrocarbons” in Ullmann's Encyclopedia of Industrial Chemistry 2006, Wiley-VCH, Weinheim. doi:10.1002/14356007.a06_233.pub2.
2. ↑ epa.gov

External links

• Agency for Toxic Substances and Disease Registry: 1,1-Dichloroethenede:1,1-Dichlorethen

it:1,1-dicloroetene nl:1,1-dichlooretheen ja:1,1-ジクロロエチレン