Discrete Mono-, Di-, and Trinuclear Anions [MoOF5](-), [(MoOF5)-O-V](2-), [MoO2F4](2-), [Mo2O2F9](-), [Mo3O3F13](-), and the Infinite Chain Anion [MoO2F3](-) Obtained from Reactions of MoOF4: Synthesis and Analysis of the Structure-Chemical Relations of the Compounds

Compounds containing discrete mono-,di-, and trinuclearanions [MoOF5](-), [(MoOF5)-O-V](2-), [MoO2F4](2-), [Mo2O2F9](-), [Mo3O3F13](-),and the infinite chain anion [MoO2F3](-) have been obtained from reactions of MoOF4 and the Mooxides with metal fluorides in aqueous or anhydrous HF, BrF3, and ClF3. The structure chemical relations of the compoundsare elucidated. The herein-reported oxyfluoridometallate salts were synthesizedand structurally characterized during the studies of the Lewis acidityof MOF4 (M = Mo, W) withvarious fluoride ion donors (RbF, CsF, TlF, AgF, SrF2,BaF2, PbF2) in different solvents (aqHF 48%,aHF, BrF3, ClF3). Phase-pure MoOF4 was either synthesized by hydrolysis of MoF6 with SiO2 in anhydrous HF (aHF) or by reactions of BrF3 withMoO(2) or MoO3, respectively. The compound wascharacterized by infrared and Raman spectroscopy, solid-state quantum-chemicalcalculations, as well as powder and single-crystal X-ray diffraction.MoOF4 reacted with PbF2 in aHF forming Pb[MoOF5](2), while under comparable conditions, WOF4 formed Pb-3[WOF5](4)F-2, containing the [WOF5](-) anion. Saltscontaining such [MoOF5](-) anions werealso directly obtained from reactions of BrF3, MoO3, and AF(2) (A =Sr, Ba), while with AgF, the compound Ag[Mo2O2F9] was observed. ClF3 reacted with MoO3 to form [ClOF2][Mo3O3F13]. Carrying out similar reactions in aqueous HF (aqHF) inautoclaves under hydrofluorothermal conditions leads to O-richer compoundswith the composition A[MoO2F4] (A = Sr, Ba). With RbF or Tl-2(CO3), the compounds A[MoO2F3] (A = Rb, Tl) were obtained. With CsF reductionto Mo(V) occurred as Cs-2[(MoOF5)-O-V]was formed. We report on similarities and differences within the respectiveanions and within the crystal structures of these compounds.

Automated summary

The chemical structure relationships of compounds containing various oxyfluoridoanions were studied. These compounds were synthesized and characterized during the investigation of Lewis acidity of MOF4 with different fluoride ion donors in different solvents. The findings contribute to a better understanding of the Lewis acidity of oxyfluoridometallate salts.