ChemInform Abstract: Strontium Vanadium Oxide—Hydrides: “Square‐Planar” Two‐Electron Phases.

Abstract

Strontium Vanadium Oxide-Hydrides: "Square-Planar" Two-Electron Phases.-SrVO 2H, Sr2VO3H, and Sr3V2O5H2 are prepared by topochemical replacement of oxide ions in SrVO 3, Sr2VO4, and Sr3V2O7, resp., by hydride ions using CaH2 (600-630 C). The samples are characterized by powder neutron and X-ray diffraction and magnetic measurements. SrVO2H crystallizes in the tetragonal space group P4/mmm. Sr 2VO3H and Sr3V2O5H2 crystallize in the orthorhombic space group Immm. The structures of the new phases contain sheets or chains of apex-linked V III O4 squares stacked with SrH layers/chains. All three oxide-hydride phases show surprising strong antiferromagnetic coupling, with SrVO2H exhibiting a Neel temperature >300 K. The "parent" materials of a number of unconventional superconducting phases are antiferromagnetic insulators, and the unusual magnetic properties of the strontium vanadium oxide-hydride phases may be a prelude to similar behavior. -(DENIS ROMERO, F.; LEACH, A.; MOELLER, J. S.; FORONDA, F.; BLUNDELL, S. J.; HAYWARD*, M. A.; Angew. Chem., Int. Ed. 53 (2014) 29, 7556-7559, http://dx.doi.org/10.1002/anie.201403536 ; Dep. Chem., Univ. Oxford, Oxford OX1 3QR, UK; Eng.) -W. Pewestorf 40-015