Bis(tetraphenylarsonium) hexafluoridotechnetate(IV) dihydrate: preparation,structure and spectroscopic analysis

Reports of quadrivalent transition‐metal fluoride salts containing bulky organic cations are limited. In this context, we prepared the bis(tetraphenylarsonium) hexafluoridotechnetate(IV) dihydrate salt, (C₂₄H₂₀As)₂TcF₆]·2H₂O, by a cation metathesis reaction of (NH₄)₂TcF₆] in water. This is the first report of an arsonium salt of the hexafluoridotechnetate(IV) dianion. (AsPh₄)₂TcF₆]·2H₂O crystallizes in the triclinic space group P. The TcF₆]^2? anion adopts a slightly distorted octahedral geometry with an average Tc—F bond length of 1.933 Å. The cyclic voltammogram of (AsPh₄)₂TcF₆]·2H₂O in CH₃CN shows a one‐electron reversible oxidation wave at 1.496 V.