The tetrafl uorides of selenium and tellurium are similar to SF 4 both structurally (in the gaseous mol-ecules) and in terms of reactivity. However, the bonding in condensed phases is different and leads to
several types of structures. Selenium tetrafl uoride can be prepared by combining the elements, but it
can also be obtained by the reaction of SeO 2 with SF 4 at high temperature. The tellurium compound
can be prepared by the reaction of SeF 4 and TeO 2 at 80°C.