Magnetic properties of polynuclear oxovanadium(IV) complexes with tetradentate Schiff base ligands

Temperature dependence measurements of magnetic susceptibilities and low-temperature magnetization of tetradentate Schiff base–oxovanadium(IV) complexes, [VO(salpn)] (1), [VO(5-NO2salen)]·2H2O (2), and [VO(3-EtOsal-meso-stien)]·H2O (3) were carried out. Orange 1 and brown 2, which take linear chain structures (VO⋯VO⋯) in the solid state, show dominant ferromagnetic intermolecular interactions (J=+5.2 and +5.7 cm−1, respectively) on which very weak antiferromagnetic interactions between the chains are superimposed. However, green 3, which takes a fairly elongated linear chain structure (V⋯O distance: 4.060(2) Å) in the crystal, shows an isolated doublet state.