A series of strontium vanadium oxide-hydride phases prepared by utilizing a low-temperature synthesis strategy in which oxide ions in Sr(n+1)V(n)O(3n+1) (n=∞, 1, 2) phases are topochemically replaced by hydride ions to form SrVO2H, Sr2VO3H, and Sr3V2O5H2, respectively. These new phases contain sheets or chains of apex-linked V(3+)O4 squares stacked with SrH layers/chains, such that the n=∞ member, SrVO2H, can be considered to be analogous to "infinite-layer" phases, such as Sr(1-x)Ca(x)CuO2 (the parent phase of the high-T(c) cuprate superconductors), but with a d(2) electron count. All three oxide-hydride phases exhibit strong antiferromagnetic coupling, with SrVO2H exhibiting an antiferromagnetic ordering temperature, T(N)>300 K. The strong antiferromagnetic couplings are surprising given they appear to arise from π-type magnetic exchange.

A series of strontium vanadium oxide-hydride phases prepared by utilizing a low-temperature synthesis strategy in which oxide ions in Sr n+1 V n O 3n+1 (n = 1, 1, 2) phases are topochemically replaced by hydride ions to form SrVO 2 H, Sr 2 VO 3 H, and Sr 3 V 2 O 5 H 2 , respectively. These new phases contain sheets or chains of apex-linked V 3+ O 4 squares stacked with SrH layers/chains, such that the n = 1 member, SrVO 2 H, can be considered to be analogous to "infinite-layer" phases, such as Sr 1Àx Ca x CuO 2 (the parent phase of the high-T c cuprate superconductors), but with a d 2 electron count. All three oxide-hydride phases exhibit strong antiferromagnetic coupling, with SrVO 2 H exhibiting an antiferromagnetic ordering temperature, T N > 300 K. The strong antiferromagnetic couplings are surprising given they appear to arise from p-type magnetic exchange.

No abstract

No 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