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Synthèse et étude structurale de Na9Cr(MoO4)6
Wassim Dridi1, Ines Ennajeh1, Mohamed Faouzi Zid1
1Laboratoire de Matériaux et Cristallochimie, Faculté des Sciences de Tunis, Université de Tunis El Manar, 2092 El Manar Tunis, Tunisia.
Abstract:
The title compound, nona-sodium chromium(III) hexa-kis[molybdate(VI)], Na9Cr(MoO4)6 was prepared by solid-state reactions. The basic structure units are isolated polyhedral clusters composed of a central CrO6 octa-hedron sharing vertices with six MoO4 tetrahedra to form an open framework in which the Na(+) cations are bound to the free vertices of the MoO4 tetra-hedra. The Cr(3+) cation has site symmetry of 32 (6a), one Na atom sits on a twofold axis (18e), and all other atoms are at general positions. The bond-valance-sum model confirms the expected values of ion charges. The title compound is isotypic with Na9Sc(MoO4)6 and Na9Fe(MoO4)6. It is compared and discussed with similar structures.
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