6745. Octafluorocyclobutane

Nomenclature

CAS number: 115-25-3
Perfluorocyclobutane; Freon C318 (DuPont).
C4F8; mol wt 200.03.
C 24.02%, F 75.98%.

Description and references

Prepd by pyrolysis of chlorodifluoromethane: Downing et al., US 2384821 (1945 to Kinetic Chem.); US 2551573; US 2615926 (1951; 1952 to du Pont). Thermodynamic studies: Furukawa et al., J. Res. Natl. Bur. Stand. 52, 11 (1954); Duus, Ind. Eng. Chem. 47, 1445 (1955).

Chemical structure

Properties

Nonflammable, nontoxic gas. d27vapor 8.2. mp -41.4°. bp -6.04° (also reported bp -5°). Heat of formation at 25° = 352 kcal. Heat of combustion 1359 ±39 cal/g.

Use

Refrigerant; heat-transfer medium.