Publication Date:
2014-03-11
Description:
The title compound, hexapotassium octairon(II,III) dodecaphosphonate, exhibiting a two-dimensional structure, is a new mixed alkali/3dmetal phosphite. It crystallizes in the space groupRoverline{3}m, with two crystallographically independent Fe atoms occupying sites of overline{3}m(Fe1) and 3m(Fe2) symmetry. The Fe2 site is fully occupied, whereas the Fe1 site presents an occupancy factor of 0.757 (3). The three independent O atoms, one of which is disordered, are situated on a mirror and all other atoms are located on special positions with 3msymmetry. Layers of formula [Fe3(HPO3)4]2−are observed in the structure, formed by linear Fe3O12trimer units, which contain face-sharing FeO6octahedra interconnected by (HPO3)2−phosphite oxoanions. The partial occupancy of the Fe1 site might be described by the formation of two [Fe(HPO3)2]−layers derived from the [Fe3(HPO3)4]2−layer when the Fe1 atom is absent. Fe2+is localized at the Fe1 and Fe2 sites of the [Fe3(HPO3)4]2−sheets, whereas Fe3+is found at the Fe2 sites of the [Fe(HPO3)2]−sheets, according to bond-valence calculations. The K+cations are located in the interlayer spaces, between the [Fe3(HPO3)4]2−layers, and between the [Fe3(HPO3)4]2−and [Fe(HPO3)2]−layers.
Electronic ISSN:
2053-2296
Topics:
Chemistry and Pharmacology
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Geosciences
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Physics
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