Journal of the American Chemical Society, Vol.135, No.51, 19268-19274, 2013
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 [enH(2)]Cu(H2O)(2)[V2O2F8] (1) and [Cu(H2O)(2,2'-bpy)](2)[V2O2F8] (2) (where enH(2) = 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 pi-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.