9055. Tantalum Pentafluoride

Nomenclature

CAS number: 7783-71-3
F5Ta; mol wt 275.94.
F 34.42%, Ta 65.58%.
TaF5.

Description and references

Prepd from tantalum pentachloride by the halide exchange method according to the equation TaCl5 +5HF → TaF5 + 5HCl: Ruff, Zedner, Ber. 42, 492 (1909); Ruff, Schiller, Z. Anorg. Allg. Chem. 72, 329 (1911); Kwasnik in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed, 1963) pp 255-256. Prepn from the elements: Fairbrother, Frith, J. Chem. Soc. 1951, 3051. Review of transition metal pentafluorides: Peacock, Adv. Fluorine Chem. 7, 113-145 (1973).

Properties

Deliquescent, strongly refractive prisms. d20 4.74. mp 96.8°. Also reported as 95.1°: Fairbrother, Frith, loc. cit. bp 229.5°. Sol in water and ether with formation of oxyfluoro complexes. Also sol in concd nitric acid, more sol in fuming nitric acid. Sparingly sol in hot carbon disulfide and hot carbon tetrachloride. Etches glass slowly.

Use

Friedel-Crafts catalyst.