Oxo-Hydroxoferrate K_2-x Fe₄O_7-x (OH) _x : Hydroflux Synthesis, Chemical and Thermal Instability, Crystal and Magnetic Structures.

ABSTRACT: The reaction of Fe(NO₃)₃⋅9 H₂O with KOH under hydroflux conditions at about 200 °C produces red crystals of K_2-x Fe₄O_7-x (OH) _x in a quantitative yield. In the crystal structure, edge-sharing [FeO₆] octahedra form ∞2[ Fe₂O₆] honeycomb nets. Pillars consisting of pairs of vertex-sharing [FeO₄] tetrahedra link the honeycomb layers and form columnar halls in which the potassium ions are located. The trigonal (P 3‾ 1m) and the hexagonal (P6₃/mcm) polytypes of K_2-x Fe₄O_7-x (OH) _x show oriented intergrowth. The sub-stoichiometric potassium content (x<

SUBMITTER: Albrecht R 

PROVIDER: S-EPMC6345222 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature