Perxenate

[2] This anion has octahedral molecular geometry, as determined by Raman spectroscopy, having O–Xe–O bond angles varying between 87° and 93°.

It has not been isolated as a free acid, because under acidic conditions it rapidly decomposes into xenon trioxide and oxygen gas:[6][7] Its extrapolated formula, H4XeO6, is inferred from the octahedral geometry of the perxenate ion (XeO4−6) in its alkali metal salts.

[8] Due to its rapid decomposition under acidic conditions as described above, however, it is most commonly known as perxenate salts, bearing the anion XeO4−6.

[6][2] Perxenic acid and the anion XeO4−6 are both strong oxidizing agents,[9] capable of oxidising silver(I), copper (II) and manganese(II) to (respectively) silver(III), copper(III),[10] and permanganate.

[10] Sodium perxenate, Na4XeO6, can be used for the analytic separation of trace amounts of americium from curium.