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[V2O2F8] (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 O2– 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.