Xenon Tetrafluoride, (XeF4)
Metals & Non-Metals > Noble Gases
Crystals of XeF4
It is a compound of xenon with fluorine . In this compound, xenon exhibits an oxidation state of +4.
Preparation:
XeF4 is obtained in good amounts by heating a mixture of xenon and fluorine in the molar ratio 1:5 at 873 K and 7 bar pressure in an enclosed nickel vessel for a few hours.
Physical properties:
- It is colourless crystalline solid, and can be sublimed.
- It melts at 390 K. XeF4 is a strong oxidising and fluorinating agent.
Square planar structure of Xenon Tetrafluoride
XeF4 is a planar molecule. Valence bond representation of XeF4 may be explained if, two electrons from 5p orbitals are promoted to 5d orbital
One 5s, three 5p and two 5d atomic orbitals of xenon hybridize to give six sp3d2 hybridized orbitals. The four singly occupied hybridized orbitals are used by four fluorine atoms for bond formation and the rest two are occupied by lone pairs.
Chemical Properties:
- With hydrogen, at 130°C, it gets reduced to xenon.
- With fluorine it produces higher fluorides.
- It acts as a strong oxidising agent. It oxidises iodide to iodine.
- It is a good fluorinating agent.
- It reacts violently with water.
- With SbF5 : XeF4 reacts with covalent pentafluorides such as PF5, AsF5 and SbF5 to form adducts. In these reactions, XeF4 acts as a fluoride ion donor (Lewis base) and the pentafluoride, a fluoride ion acceptor (Lewis acid). With SbF5, the reaction is,
