Original scientific paper

Novel Ternary Oxobromides with Ta₆ Clusters and Rare Earths: The Synthesis of (RE)Ta₆Br₁₃O₃ (RE = Rare Earth) and the Crystal Structure of LuTa₆Br₁₃O₃

Stéphane Cordier ; Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS 1495, Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes Cédex, France
Christiane Perrin ; Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS 1495, Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes Cédex, France
Marcel Sergent ; Laboratoire de Chimie du Solide et Inorganique Moléculaire, URA CNRS 1495, Université de Rennes I, Avenue du Général Leclerc, 35042 Rennes Cédex, France

Abstract

Crystallochemistry of the novel oxobromides (RE)TagBr1803 with RE = Sm to Lu (except Eu and Yb) is reported. All these compounds, which exhibit 14 valence electrons per Tag cluster, are isotypic with ScNbgCl^Og with the space group 74x22. The structure of LuTagBrxgOg has been determined from single crystal X-ray diffraction: a = 9.383(1) Å and c = 54.60(1) Å, R = 0.050 and Rw = 0.054 for 755 symmetry-independent reflections. For this compound, the (TagL18) units (L = Br and O), in which the Tag cluster is very distorted, are linked together by four bridging bromines to form pseudo-helices of units. The lutetium is five-coordinated at a small site formed by three oxygen and two bromine atoms belonging to three adjacent units. The formula developed for this compound is Lu(TagBr91031)Br2aBr4/2a_a. These structural results allow discussion of the influence of interatomic distances on the potential properties of these novel ternary tantalum oxobromides in relation to the oxidation state of the cluster.

Keywords

Hrčak ID:

136693

URI

https://hrcak.srce.hr/136693

Publication date:

1.11.1995.

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