Spin frustration from cis -edge or -corner sharing metal-centered octahedra

A new strategy using cis-edge or -corner sharing metal-centered octahedra is described which enables interesting frustrated spin lattices to be targeted. The examination of "CuV₂" triangular motifs in the two new compounds [enH₂]Cu(H₂O)₂[V₂O ₂F₈] (1) and [Cu(H₂O)(2,2′-bpy)] ₂[V₂O₂F₈] (2) (where enH₂ = ethylenediammonium and 2,2′-bpy =2,2′-bipyridyl) reveals that the [VOF₄]^2- anions, which exhibit cis structure directing properties, lead to frustrated lattices owing to the competing ferro and antiferromagnetic interactions. There is direct coordination through two cis F^- ligands (i.e., the F^- ligand trans to O^2- and one equatorial F^- ligand) in both 1 and 2 owing to the significant π-bonding between the vanadium and the oxide ligand. We emphasize that most of triangular motifs reported in the literature are built of cis-edge or -corner sharing metal-centered octahedra, thus they can be used to target new materials exhibiting interesting magnetism such as spin frustration.