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Crystal structure of Cs2GdNb6Cl15O3 in the structural evolution of niobium oxychlorides with octa-hedral Nb6-cluster
Saronom Silaban1, Maefa Eka Haryani2, Fakhili Gulo3
1Department of Chemistry, Medan State University, Medan 20221, Indonesia.
Abstract:
Cs2GdNb6Cl15O3, dicaesium gadolinium hexa-niobium penta-deca-chloride trioxide, was synthesized by solid-state reactions starting from a stoichiometric mixture of CsCl, Gd2O3, Nb, NbCl5, and Nb2O5. The crystal structure is based on octa-hedral Nb6 cluster units (point group symmetry 3.2) with composition [(Nb6Cli 9Oi 3)Cla 6]5- where i and a denote inner and outer ligands. Cs2GdNb6Cl15O3 exhibits 14 valence electrons per cluster unit. The cluster units are linked to each other by CsI and GdIII atoms, whereby CsI (site symmetry 3..) is 12-coordinated by six Cli and six Cla ligands belonging to six neighboring cluster units and GdIII (site symmetry 3.2) is 9-coordinated by three Oi and six Cli ligands belonging to three adjacent cluster units. The arrangement of cluster units corresponds to a stacking of …AA'A… layers along [001]. Cs2GdNb6Cl15O3 is isotypic with Cs2UNb6Cl15O3.
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