Hexafluoroacetone

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Hexafluoroacetone
Hexafluoropropanone 3D structure
1,1,1,3,3,3-hexafluoropropanone
Identifiers
CAS number 684-16-2 YesY
ChemSpider 13846015 YesY
ChEBI CHEBI:39429 YesY
RTECS number UC2450000
Jmol-3D images Image 1
Properties
Molecular formula C3F6O
Molar mass 166.02 g/mol
Appearance Colorless gas
Density 1.32 g/ml, liquid
Melting point −129 °C (144 K)
Boiling point −28 °C (245 K)
Solubility in water Reacts with water
Hazards
R-phrases R14, R23/24/25,
R34, R60, R63
S-phrases S7/9, S26, S28,
S36, S45, S53
Main hazards Toxic (T),
Corrosive (C)
NFPA 704
Flammability (red): no hazard code Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g., phosphorus Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point N/A
Related compounds
Related organofluorides Hexafluoro-2-propanol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Hexafluoroacetone is a chemical compound with the formula CF3-CO-CF3. It is structurally similar to acetone, however its reactivity is markedly different. It comes in the form of a colourless, hygroscopic, nonflammable, highly reactive gas characterized by a musty odour.[1] The most common form of this substance is hexafluoroacetone sesquihydrate (1.5 H2O), which is a geminal diol.

Synthesis and reactions[edit]

(CF3)2CO is prepared in a two step process from perfluoropropene. In the first step KF catalyzes the reaction of the alkene with elemental sulfur to give the 1,3-dithete [(CF3)2CS]2. This species is then oxidized by iodate to give (CF3)2CO.[2]

Uses[edit]

Hexafluoroacetone is mostly employed in organic synthesis, but it is also the main chemical intermediate used in the production of hexafluoroisopropanol, as well as polymethyl methacrylates and polyesters for textile coating. Hexafluoroacetone can be employed as a solvent for acetal resins, polyamides, polyglycolide, polyacetals, and polyols or as a polymer adhesive.

Reactivity[edit]

Hexafluoroacetone is a reactive substance, acting primarily as an electrophile. In water hexafluoroacetone is highly reactive as its equilibrium sharply favors (~106) forming a geminal diol hydrate, unlike the identical unfavorable equilibrium with acetone (10-3).[3] This makes the equilibria of two chemicals differ by a factor of about a billion regarding this addition of water.[3] Hexafluoroacetone-hydrates are acidic and react with most metals to generate hydrogen. Hexafluoroacetone violently reacts in the presence of alkali. Related to its tendency to hydrate, (CF3)2CO adds ammonia to give (CF3)2C(OH)(NH2) which can be dehydrated with phosphoryl chloride to give (CF3)2CNH.[4]

References[edit]

  1. ^ CDC - NIOSH Pocket Guide to Chemical Hazards
  2. ^ Van Der Puy, M. ; Anello, L. G. (1990), "Hexafluoroacetone", Org. Synth. ; Coll. Vol. 7: 251 
  3. ^ a b Lemal, David M. (2004). "Perspective on Fluorocarbon Chemistry". The Journal of Organic Chemistry 69 (1): 1–11. doi:10.1021/jo0302556. PMID 14703372. 
  4. ^ Middleton, W. J.; Carlson, H. D. (1988), "Hexafluoroacetoneimine", Org. Synth. ; Coll. Vol. 6: 664