Gd4I6CN: Ein Carbidnitrid mit Ketten aus Gd6(C2)-Oktaedern und Gd6N2-Tetraederdoppeln |
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Authors: | Hansjü rgen Mattausch,Horst Borrmann,Roland Eger,R. K. Kremer,Arndt Simon |
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Abstract: | Gd4I6CN: A Carbide Nitride with Chains of Gd6(C2) Octahedra and Gd6N2 Double Tetrahedra The compound α-Gd4I6CN is prepared by reaction of Gd, GdI3, C, and GdN (1:2:1:1 mole ratio) at 1 170 K in sealed Ta tubes. It is obtained as brown red, transparent needles which are air and moisture sensitive. The structure of α-Gd4I6CN contains Gd6 octahedra centered by C2 groups and double tetrahedra centered by N atoms. The units are alternatingly connected via common edges to form chains (Gd2Gd4/2C2) (Gd2/2Gd2/2N)2 parallel [001]. The linear chains are surrounded by I atoms above all free edges of the metal polyhedra and linked according to (Gd2Gd4/2C2) (Gd2Gd4/2N2)I4/2I8I2 in the a – b plane. We also found β-Gd4I6CN, which is formed in a monotropic transition from the α-form. In the structure the chains of Gd octahedra and tetrahedra as described for α-Gd4I6CN are more densely packed. The structure of Y6I9C2N is composed by chains of pairs of Y-octahedra and Y-tetrahedra, respectively. The octahedra are centered by C2 groups, the tetrahedra by N-atoms. We also synthesized the compounds Gd4Br6CN und La4I6CN by tempering at 1 220 K. They are isotypic with α-Gd4I6CN. |
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Keywords: | Gadolinium Iodide Carbide Nitride Gadolinium Bromide Carbide Nitride Yttrium Iodide Carbide Nitride Lanthanum Iodide Carbide Nitride preparation X-ray single crystal structure investigation crystal structure condensed cluster chain of condensed octahedra and double tetrahedra C?C single bond Gd6(C2) octahedron Gd6N2 double tetrahedron Y10(C2)2 double octahedron Y6N2 double tetrahedron α -Gd4I6CN, β -Gd4I6CN, Y6I9C2N, α -Gd4Br6CN, α -La4I6CN |
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