Dichlorodifluoroethylene

A dichlorodifluoroethylene (systematically named dichlorodifluoroethene) is one of three compounds with the chemical formula. Dichlorodifluoroethylenes are colourless gases, and are some of the simplest chlorodifluoroalkenes.

The structural isomers are used as intermediates or precursors in the production of other industrial chemicals.

1,1-Dichloro-2,2-difluoroethylene
1,1-Dichloro-2,2-difluoroethylene is a low-boiling liquid that is used a refrigerant. It may also be used as a solvent, but has practical limitations as such, because of its low boiling point (commercial listings, 19 °C; lit. 17 °C).

It is regarded as a hazardous chemical for being toxic by inhalation (see MSDS), and a low-boiling liquid, and it causes irritation when it comes into contact with the skin and mucous membranes. Its ASHRAE number is R-1112a, and its CAS number is 79-35-6. Concentrated 1,1-dichloro-2,2-difluoroethylene can be ignited with ease in the laboratory.

cis- And trans-1,2-dichloro-1,2-difluoroethylene
The diastereomers were co-isolated first in 1965, by using a combination of fractional melting and fractional distillation. The cis isomer's ASHRAE number is R-1112c, and its CAS number is 311-81-9. Its melting point is −119.6 C. The trans isomer's ASHRAE number is R-1112t, and its CAS number is 381-71-5. Its melting point is −93.3 C. The diastereomers are commercially only available as a mixtures of varying proportions.