Tungsten oxytetrafluoride

Tungsten oxytetrafluoride is an inorganic compound with the formula WOF4. It is a colorless diamagnetic solid. The compound is one of many oxides of tungsten. It is usually encountered as product of the partial hydrolysis of tungsten hexafluoride.

Structure
As confirmed by X-ray crystallography, WOF4 crystallizes as a tetramer. The oxides are terminal, and four of the fluorides are bridging. Its structure is similar to those for niobium pentafluoride and tantalum pentafluoride. In contrast, molybdenum oxytetrafluoride adopts a polymeric structure, although again the fluorides bridge and the oxides are terminal.

In the gas state, this molecule is a monomer. It can form complexes with acetonitrile and other compounds.

Preparation
Tungsten(VI) oxytetrafluoride can be synthesized by the reaction of fluorine and tungsten trioxide.

It can also be obtained by treating tungsten with a mixture of oxygen and fluorine at high temperatures. Partial hydrolysis of tungsten hexafluoride will also produce WOF4.
 * WF6 + H2O -> WOF4 + 2 HF

The reaction of tungsten(VI) oxytetrachloride and hydrogen fluoride will also produce WOF4.
 * WOCl4 + 4HF -> WOF4 + 4HCl

WOF4 can also prepared by the reaction of lead(II) fluoride and tungsten trioxide at 700 °C.
 * 2PbF2 + WO3 -> WOF4 + 2PbO

Tungsten(VI) oxytetrafluoride hydrolyzes into tungstic acid.
 * WOF4 + 2 H2O -> WO3 + 4 HF