| Chemical Properties | Hexafluoroethane is a colorless and odorless gas, or liquid under pressure. asphyxiant in high concentrations. Gas density is heavier than air. Hexafluoroethane is chemically inert and has a very high global warming potential (GWP = 11,100; Greenhouse gas protocol, Fifth Assessment Report AR5). It is an etchant and chamber cleaning agent. |
| Uses | Hexafluoroethane is used as an important component in some refrigeration mixtures, and as a reactive ion etching gas in semiconductor materials processing applications. It can be used for selective etching of metal silicides and oxides versus their metal substrates and also for etching of silicon dioxide over silicon.
In semiconductor applications, for example in reactive ion etching, hexafluoroethane with a fluorine to carbon ratio of 3:1 offers a unique source of highly reactive trifluoromethyl radicals without accompanying hydrogen atoms.As a result, semiconductor material plasma etching processes employing hexafluoroethane are relatively aggressive with respect to fluorine radical formation. |
| Definition | ChEBI: Hexafluoroethane is a fluoroalkane and a fluorocarbon. It has a role as a refrigerant. |
| Synthesis Reference(s) | Journal of the American Chemical Society, 77, p. 3007, 1955 DOI: 10.1021/ja01616a025 |
| General Description | HEXAFLUOROETHANE is a colorless, odorless gas. HEXAFLUOROETHANE is relatively inert. The mixture is nonflammable and nontoxic, though asphyxiation may occur because of displacement of oxygen. Under prolonged exposure to fire or intense heat the containers may rupture violently and rocket. |
| Reactivity Profile | HEXAFLUOROETHANE is chemically inert in many situations, but can react violently with strong reducing agents such as the very active metals and the active metals. Can react with strong oxidizing agents or weaker oxidizing agents under extremes of temperature. |
| Health Hazard | Vapors may cause dizziness or asphyxiation without warning. Vapors from liquefied gas are initially heavier than air and spread along ground. Contact with gas or liquefied gas may cause burns, severe injury and/or frostbite. Fire may produce irritating, corrosive and/or toxic gases. |
| Fire Hazard | Some may burn but none ignite readily. Containers may explode when heated. Ruptured cylinders may rocket. |
| Potential Exposure | It is used as a coolant, in dielectric
fluids; as a propellant and refrigerant. |
| Shipping | UN2193 Hexafluoroethane or Refrigerant gas
R-116, Hazard Class: 2.2; Labels: 2.2-Nonflammable
compressed gas. |
| Purification Methods | Purify it for pyrolysis studies by passing through a copper vessel containing CoF3 at ca 270o, and hold for 3hours in a bottle with a heated (1300o) platinum wire. It is then fractionally distilled. [Steunenberg & Cady J Am Chem Soc 74 4165 1962, Beilstein 1 IV 132.] |
| Incompatibilities | Active metals. Keep away from heat and
sunlight. |
| Waste Disposal | Return refillable compressed
gas cylinders to supplier. |
