Hexafluoroethane

Structural formula
General
Surname	Hexafluoroethane
other names	R-116 Freon 116 Perfluoroethane FC-116 PFC116
Molecular formula	C 2 F 6
Brief description	colorless and odorless gas
External identifiers / databases
CAS number 76-16-4 EC number 200-939-8 ECHA InfoCard 100,000,855 PubChem 6431 Wikidata Q417035
properties
Molar mass	138.01 g mol −1
Physical state	gaseous
density	6.25 kg m −3 (under normal conditions )
Melting point	−101 ° C
boiling point	−78.2 ° C
solubility	slightly soluble in water
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 280 P: 403
Global warming potential	12340 (based on 100 years)
Thermodynamic properties
ΔH f 0	−1344.2 kJ / mol
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Hexafluoroethane is a chemical compound from the group of fluorocarbons and is a perfluorocarbon as an aliphatic saturated fluorocarbon .

Presentation and extraction

One synthesis variant is the reaction of trifluoroacetic acid with xenon difluoride . Here, the unstable esters (CF ₃ COO) ₂ Xe and (CF ₃ COO) XeF are first formed, the decomposition or decarboxylation of which leads to trifluoromethyl radicals and then to hexafluoroethane.

properties

Hexafluoroethane is a compressed gas in pressurized gas cylinders . Under 19.7 ° C under pressure it is a liquefied gas. When the liquid flows out or when large amounts of gas escape, cold mists form and spread across the floor. The compound decomposes above 800 ° C, producing hydrogen fluoride , carbon monoxide and carbon dioxide under air . The critical point is 19.89 ° C, 30.39 bar and 0.601 kg · l ⁻¹ ; the triple point at −100.10 ° C and 0.26490 bar.

Hexafluoroethane has a global warming potential of 12340 and an ozone depletion potential of 0.

use

Hexafluoroethane is used in the semiconductor industry as an etching gas and in plasma etching , as well as for cleaning CVD chambers . It also serves as a propellant gas , gaseous insulating material (in foamed materials) and as a refrigerant . Large amounts of hexafluoroethane are released during aluminum production.

safety instructions

Hexafluoroethane is heavier than air and suffocating in high concentrations.

Individual evidence

1. ↑ ^{a b c d e f g h} Entry on hexafluoroethane in the GESTIS substance database of the IFA , accessed on February 22, 2017(JavaScript required) .
2. ↑ G. Myhre, D. Shindell et al .: Climate Change 2013: The Physical Science Basis . Working Group I contribution to the IPCC Fifth Assessment Report. Ed .: Intergovernmental Panel on Climate Change . 2013, Chapter 8: Anthropogenic and Natural Radiative Forcing, pp. 24-39; Table 8.SM.16 ( PDF ).
3. ↑ David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-21.
4. ↑ e-EROS Encyclopedia of Reagents for Organic Synthesis , 1999–2013, John Wiley and Sons, Inc., entry for Xenon (II) fluoride, accessed January 20, 2018 .
5. ↑ Helmut Schan: Handbook of the purest gases. Springer, 2005, ISBN 978-3-540-23215-5 , p. 307.
6. ↑ hexafluoroethane (airliquide)
7. ↑ R116 (Linde gas)