Question

How would you account for the square pyramidal structure of XeOF₄ molecule? Explain the formation of the molecule.

Answer 1

Xenon oxytetrafluoride can be prepared by the partial hydrolysis of xenon hexafluoride with water.

\[\ce{XeF6 + H2O -> XeOF4 + 2HF}\]

It can also be obtained by treating XeF₆ with silica (SiO₂).

\[\ce{2XeF6 + SiO2 -> 2XeOF4 + SiF4}\]

At about 245K, the colourless volatile liquid freezes. It can be kept in a nickel jar and is stable at room temperature. Compared to XeF₆, it is more volatile. It produces XeO₂F₂ when it combines with water.

\[\ce{XeOF4 + H2O -> XeO2F2 + 2HF}\]

The final product in the above reaction is XeO₃.

The Xe atom in its third excited state undergoes sp³d²-hybridisation to generate the square pyramidal molecule known as XeOF₄. The figure shows this molecule’s formation and structure.