Abstract The properties of PF5, HPF4, H2PF3, and H3PF2 (Δ5[sgrave]5P derivatives of (HO)3PO, (HO)2HPO, (HO)H2PO, and of the hypothetic H3PO) and the formation of the related Δ5[sgrave]6P anions PF6 –, HPF5 –, and trans-H2PF4 – have been studied some years ago 1–4. The mono and spirocyclic dioxa and tetraoxa analogues, 1 and 2 available from the corresponding precursor phosphoranes by fluoride addition could be found also as products in the reaction of phosphite 35 and K+(CF3)2CFO– together with two other phosphates, 4 and 5. A 19F–19F homocorrelated 2 D NMR spectrum of 2 indicated coupling of the P–F fluorine nuclei with two CF3 groups by a non bond mechanism.