Nomenclature
CAS number: 2551-62-4
F
6S; mol wt 146.06.
F 78.04%, S 21.95%.
SF
6.
Description and references
Prepd by direct fluorination of sulfur or sulfur
dioxide: Moissan, Lebeau, Compt. Rend. 130, 865, 984 (1900); eidem, Ann. Chim. Phys. [7] 26, 147 (1902); Schumb, Inorg. Synth. 3, 119 (1950); Kwasnik in Handbook
of Preparative Inorganic Chemistry Vol. 1, G.
Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 169-170.
Reviews: Cady, “Fluorine-Containing Compounds of Sulfur”
in Adv. Inorg. Chem. Radiochem. 2, 105-157 (1960); Kemmitt, Sharp, Adv. Fluorine Chem. 4, 218-219 (1965).
Properties
Colorless, odorless gas. Non-flammable. One of the heaviest known gases; density
approx 5 times that of air. mp 50.8°. Sublimes at 63.8°. Crit temp 45.6°. d (liq; 50.8°) 1.88.
Sparingly sol in water, somewhat more in alcohol. At 25° and 1 atm
0.297 ml SF6 dissolves in 1.0 ml of transformer oil. Thermodynamically
unstable but kinetically stable gas. This stability explained by
symmetrical, octahedral structure of the molecule. Inert to nucleophilic
attack. Does not attack glass. No fluorine exchange with HF. Stable
to silent electrical discharge. Unchanged at 500°.Caution
Potential symptoms of overexposure
are asphyxia; increased breathing rate and pulse rate; slight muscle
incoordination, emotional upset; fatigue, nausea, vomiting, convulsions.
See NIOSH Pocket Guide to Chemical
Hazards (DHHS/NIOSH 97-140, 1997) p 288.Use
In electrical circuit interrupters. In electronic
ultra-high frequency piping.