1,1-Dichloroethene

1,1-Dichloroethene

Names
IUPAC name 1,1-Dichloroethene
Other names 1,1-Dichloroethylene 1,1-DCE vinylidene chloride vinylidene dichloride
Identifiers
CAS Number	75-35-4 Y
ChEBI	CHEBI:34031 N
ChemSpider	6126 Y
Jmol 3D model	Interactive image
KEGG	C14039 Y
PubChem	6366
UNII	21SK105J9D Y
InChI InChI=1S/C2H2Cl2/c1-2(3)4/h1H2 N Key: LGXVIGDEPROXKC-UHFFFAOYSA-N N
SMILES ClC(Cl)=C
Properties
Chemical formula	C2H2Cl2
Molar mass	96.94 g/mol
Density	1.213 g/cm3
Melting point	−122 °C (−188 °F; 151 K)
Boiling point	32 °C (90 °F; 305 K)
Solubility in water	0.04% (20°C)
Vapor pressure	500 mmHg (20°C)
Dipole moment	1.3 D
Structure
Point group	C2v
Molecular shape	Planar
Vapor pressure	{{{value}}}
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
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.

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

Main article: 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 polyethylene.

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. 1,1-DCE is considered a potential occupational carcinogen by the National Institute for Occupational Safety and Health .

See also

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

External links

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