Tellurium Hexafluoride, TeF6, appears to be more stable than tellurium tetrafluoride. It has been obtained by the action of fluorine on tellurium at -78° C. The resulting colourless crystalline solid vaporises on allowing the temperature to rise. The solidified substance melts at -36° C. and boils at -35.5° C., the critical temperature being 83° C. The vapour density is 119.5, agreeing with the formula TeF6. The gas has an unpleasant odour, recalling ozone and tellurium hydride. Water only slowly decomposes the gas, which does not attack glass.
TeF6 + 4H2O = H2TeO4 + 6HF. |