title: Spin frustration from cis-edge or -corner sharing metal-centered octahedra.
abstract: 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 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.
authors.affiliation: Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60201-3113, United States.
authors.forename: Romain
authors.initials: R
authors.lastname: Gautier
authors.forename: Kengo
authors.initials: K
authors.lastname: Oka
authors.forename: Takumi
authors.initials: T
authors.lastname: Kihara
authors.forename: Nitesh
authors.initials: N
authors.lastname: Kumar
authors.forename: Athinarayanan
authors.initials: A
authors.lastname: Sundaresan
authors.forename: Masashi
authors.initials: M
authors.lastname: Tokunaga
authors.forename: Masaki
authors.initials: M
authors.lastname: Azuma
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Poeppelmeier