Title: Tellurium Hexafluoride
CAS Registry Number: 7783-80-4
Molecular Formula: F6Te
Molecular Weight: 241.59
Percent Composition: F 47.18%, Te 52.82%
Line Formula: TeF6
Literature References: Prepd by direct fluorination of tellurium metal: Prideaux, J. Chem. Soc. 89, 322 (1906); Klemm, Henkel, Z. Anorg. Allg. Chem. 207, 74 (1932); Yost, Claussen, J. Am. Chem. Soc. 55, 885 (1933); Yost, Inorg. Synth. 1, 121 (1939).
Properties: Colorless gas. Repulsive odor. mp -37.6°. Sublimes at -38.9°. Critical temperature 83°. d (solid; -191°) 4.006; d (liq; -10°) 2.499. Not as inert chemically as SeF6 and SF6 because the covalence maximum of tellurium is higher than 6. Slowly absorbed by water with hydrolysis to telluric acid, H6TeO6; more quickly hydrolyzed by aq KOH. Does not attack glass when pure. Corrodes mercury.
Melting point: mp -37.6°
Density: d (solid; -191°) 4.006; d (liq; -10°) 2.499
CAUTION: Potential symptoms of overexposure are headache; dyspnea; garlic odor on breath. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 294. |