Heptafluoroisopropyl iodide

clear colorless to yellowish liquid

Heptafluoro-2-iodopropane may be used in the preparation of perfluoropropyl magnesium bromide and perfluoropropyl magnesium iodide. It may be used as chain-transfer agent in telomerization reactions of:

• 1,1-difluoroethylene and tetrafluoroethylene
• CF₃I, C₂F₅I and n-C₃F₇I with 1,1-difluoroethylene
• n-C₃F₇I with tetrafluoroethylene

Heptafluoro-2-iodopropane is a secondary fluoro alkyl iodide. It can be prepared by addition of iodine monofluoride to hexafluoropropene.

Non flammable

25 mL of experimental fluoropropane, 97 g of potassium iodide and 76 mL of water were placed in a reaction flask, and the reaction was stirred at 75 C for 1 h. After cooling, 100 mL of ether was added, and the organic phase was washed once with 100 mL of a 10% aqueous sodium hydroxide solution, and the water was washed to neutrality, and the organic layer was dried with anhydrous magnesium sulfate, and the ether was taken out, and the remaining material was distilled under reduced pressure to give the product heptafluoro-2-iodopropane 43.1 g (80.1% yield).

Purify it by gas chromatography on a triacetin (glyceryl triacetate) column, followed by bulb-to-bulb distillation at low temperature. Store it over Cu powder to stabilise it. UV has max at 271nm ( 240) in pet ether (b 60-80o). [Haszeldine J Chem Soc 1767, 3761 1953, Beilstein 1 III 255, 1 IV 225.]