The dimeric [V2O2F8]4− anion: Structural characterization of a magnetic basic-building-unit

New materials built from the [V2O2F8]4− anionic basic-building-unit (BBU) exhibit interesting magnetic properties owing to the proximity of the two d1 V(IV) cations and the orbital interactions of fluoride and oxide ligands. In our search to target such materials, the vanadium oxide–fluoride compound [dpaH2]2[V2O2F8] in which a dimeric anion [V2O2F8]4− is isolated in a hydrogen bond network was hydrothermally synthesized (dpa=2,2′-dipyridylamine). This hydrogen bond network is able to stabilize the highly ionic species [V2O2F8]4− as demonstrated with bond valence calculations. The coordination of the O2−/F− ordered ligands was investigated and antiferromagnetic coupling of the isolated BBU was measured.

The new hybrid compound [dpaH2]2[V2O2F8] built from the interesting [V2O2F8]4− magnetic basic-building-unit (BBU) was synthesized by the hydrothermal method. The coordination of the O2−/F− ordered ligands was investigated by BVS calculations and antiferromagnetic coupling was measured. Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A new vanadium oxyfluoride was synthesized by hydrothermal method. ► The Dimeric [V2O2F8]4− basic building unit is isolated in the hydrogen bond networks. ► The coordination of [V2O2F8]4− units to the extended structure is investigated. ► Isolated [V2O2F8]4− units exhibit antiferromagnetic coupling.