1,1-Difluoroethylene

1,1-Difluoroethylene, also known as vinylidene fluoride, is a hydrofluoroolefin. This colorless, flammable gas is a difluorinated derivative of ethylene. Global production in 1999 was approximately 33,000 metric tons.^[3] It is primarily used in the production of fluoropolymers such as polyvinylidene fluoride and FKM.

1,1-Difluoroethylene

Names
Preferred IUPAC name 1,1-Difluoroethene
Other names Difluoro-1,1-ethylene; R-1132a; Halocarbon 1132 A; Freon 1132A; Vinylidene difluoride; Vinylidene fluoride[1]
Identifiers
CAS Number	75-38-7 Y
3D model (JSmol)	Interactive image
Abbreviations	VDF
ChEBI	CHEBI:82550
ChEMBL	ChEMBL116020
ChemSpider	13836545
ECHA InfoCard	100.000.789
EC Number	200-867-7
KEGG	C19547
PubChem CID	6369
RTECS number	KW0560000
UNII	3C1IX2905B Y
UN number	1959
CompTox Dashboard (EPA)	DTXSID3021439
InChI InChI=1S/C2H2F2/c1-2(3)4/h1H2 Key: BQCIDUSAKPWEOX-UHFFFAOYSA-N InChI=1/C2H2F2/c1-2(3)4/h1H2 Key: BQCIDUSAKPWEOX-UHFFFAOYAV
SMILES C=C(F)F
Properties
Chemical formula	C2H2F2
Molar mass	64.035 g·mol−1
Appearance	Colorless gas[2]
Odor	Slightly ethereal[1]
Density	2.89 kg/m3 (vapor, 0 °C)[2] 1.122 g/mL (liquid, −84 °C)[2]
Melting point	−144 °C (−227 °F; 129 K)[2]
Boiling point	−84 °C (−119 °F; 189 K)[2]
Solubility in water	0.254 g/L[3]
Vapor pressure	35.2 atm (20°C)[4]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Flammable[4]
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501
Autoignition temperature	380 °C (716 °F; 653 K)[1]
Explosive limits	5.5%-21.3%[4]
NIOSH (US health exposure limits):
PEL (Permissible)	none[4]
REL (Recommended)	TWA 1 ppm C 5 ppm[4]
IDLH (Immediate danger)	N.D.[4]
Related compounds
Related compounds	1,2-Difluoroethylene; Fluoroethylene; Trifluoroethylene; 2-Chloro-1,1-difluoroethylene;
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Preparation

1,1-Difluoroethylene can be prepared by elimination reaction from a 1,1,1-trihaloethane compound, for example, loss of hydrogen chloride from 1-chloro-1,1-difluoroethane:^[5]

or loss of hydrogen fluoride from 1,1,1-trifluoroethane:^[6]

See also

• 1,2-Difluoroethylene
• Perfluoroisobutene