Photochemistry with ClF₃ – An Access to [ClOF₂]⁺ Salts

A route to salts of the [ClOF₂]⁺ cation is described that does not require the parent fluoride ClOF₃ as a starting material. These can be obtained when either metals such as Cr, Rh, Pd and Au, halides such as PtCl₂, SnF₂ and PbF₄, or oxides such as B₂O₃, OsO₄, GeO₂, SnO and Sb₂O₄ are reacted with ClF₃ and additional O₂, where necessary, under UV irradiation. Cr, Rh, Pd, PtCl₂, GeO₂, and SnO formed salts with the respective hexafluoridometallate(IV) anion with the composition [ClOF₂]₂[MF₆]. They crystallize in two distinct structure types in either the monoclinic crystal system (M=Cr, Rh, Ge) or the orthorhombic one (M=Pd, Pt, Sn). The fluorides SnF₂ and PbF₄ were converted to the monoclinic salts [ClOF₂]MF₅, and B₂O₃ formed orthorhombic [ClOF₂][BF₄]. The triclinic compound ([ClOF₂][OsO₃F₃])₂⋅OsF₆ was obtained from OsO₄ and contains a neutral co-crystallized OsF₆ molecule. A monoclinic double salt with the composition [ClOF₂]₂[AuF₄][SbF₆] was obtained by reacting a mixture of Sb₂O₄ and Au. The compounds were investigated by single crystal X-ray diffraction and IR and Raman spectroscopy. Quantum-chemical calculations for the solid-state allowed for the band assignments of the vibrational spectra.