9328. Thiocyanic Acid

Nomenclature

CAS number: 463-56-9
Hydrogen thiocyanate; Rhodanwasserstoffsure (German).
CHNS; mol wt 59.09.
C 20.33%, H 1.71%, N 23.70%, S 54.26%.
HSCN.

Description and references

Thiocyanic acid is believed to be a tautomeric mixture of HSCN and HNCS (isothiocyanic acid): Beard, Dailey, J. Chem. Phys. 18, 1437 (1950). Conveniently prepd in the laboratory from KNCS + KHSO4: Birckenbach, Bucher, Ber. 73, 1153 (1940). Dil aq solns may be prepd from ammonium thiocyanate by the action of ion exchange resins: Klement, Z. Anorg. Allg. Chem. 260, 268 (1949). Toxicology of organic thiocyanates: Y. Yokoi, Jpn. J. Pharmacol. 3, 99 (1954), C.A. 48, 13965f (1954).

Properties

Colorless gas or white solid depending upon degree of polymerization. Freely sol in water. Very strong acid. A 5% aq soln may be kept refrigerated for several weeks. Also sol in some organic solvents.

Derivative

Ethyl ester.

Nomenclature

Ethyl thiocyanate; ethyl sulfocyanate.
C3H5NS; mol wt 87.14.
C 41.35%, H 5.78%, N 16.07%, S 36.80%.

Properties

Liquid. d423 1.007. bp 146°. nD15 1.4684. Insol in water. Misc with alcohol, ether. MLD in mice (mg/kg): 52 orally; 39.1 s.c.; 18.3 i.p.; 6 i.v. (Yokoi).