Nomenclature
CAS number: 7789-21-1
Fluorosulfuric acid; fluosulfonic acid.
FHO
3S; mol wt 100.07.
F 18.99%, H 1.01%, O 47.96%, S 32.04%.
HSO
3F.
Description and references
Prepn: Thorpe, Kirman, J. Chem. Soc. 61, 921 (1892); Meyer, Schramm, Z. Anorg. Allg. Chem. 206, 25
(1932); Kwasnik in Handbook of Preparative
Inorganic Chemistry vol. 1, G. Brauer, Ed.
(Academic Press, New York, 2nd ed., 1963) pp 177-178. Reviews of
properties and chemistry: Gillespie, Acc.
Chem. Res. 1, 202-209 (1968); Thompson, “Fluorosulfuric
Acid” in Inorganic Sulfur Chemistry, G. Nickless, Ed. (Elsevier,
New York, 1968) pp 587-606; Jache in Adv.
Inorg. Chem. Radiochem. 16, 177-200 (1974).
Properties
Colorless liquid; fumes in moist air. d418 1.740; d425 1.726. mp 89°. bp760 163°; bp120 110.0°; bp19 77.0°. Stable to 900°. Considerably more acidic than 100% H2SO4. Corrosive. Does not attack glass when anhydr and pure. Violent reaction with
water although it is incompletely and reversibly hydrolyzed. Reddish-brown
color with acetone. Forms stable salts which are little hydrolyzed
by water and which may be recrystallized from water.Caution
May be highly irritating to skin,
mucous membranes.Use
Fluorinating agent. Catalyst in alkylation, acylation,
polymerization and condensation reactions; in hydrofluorination of
olefins; in production of substituted pyridines. In production of
petroleum products.
See Thompson,
loc. cit. Magic Acid, a 1:1 HSO
3F-SbF
5 soln, is used in
the study of stable solns of alkyl- and arylcarbonium ions: Olah,
Science 168, 1298 (1970).