Germanium tetrafluoride is formed by treating germanium with fluorine: Alternatively germanium dioxide combines with hydrofluoric acid (HF):[3] It is also formed during the thermal decomposition of a complex salt, Ba[GeF6]:[4] Germanium tetrafluoride is a noncombustible, strongly fuming gas with a garlic-like odor.
It reacts with water to form hydrofluoric acid and germanium dioxide.
[5] Reaction of GeF4 with fluoride sources produces GeF5− anions with octahedral coordination around Ge atom due to polymerization.
[6] The structural characterization of a discrete trigonal bipyramidal GeF5− anion was achieved by a "naked" fluoride reagent 1,3-bis(2,6-diisopropylphenyl)imidazolium fluoride.
[7] In combination with disilane, germanium tetrafluoride is used for in the synthesis of SiGe.