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Nd 2 S 2 Te: Neodymium(III) Sulfide Telluride with Ce 2 O 2 S‐Type Crystal Structure
Author(s) -
Schleid Thomas,
Klein Eva K.
Publication year - 2001
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/1521-3749(200105)627:5<807::aid-zaac807>3.0.co;2-r
Subject(s) - telluride , neodymium , crystallography , octahedron , sulfide , chemistry , tellurium , cationic polymerization , crystal structure , inorganic chemistry , laser , physics , organic chemistry , optics
Single‐phase neodymium(III) sulfide telluride Nd 2 S 2 Te can be obtained from 2 : 2 : 1‐molar mixtures of the elements (Nd, S, and Te) after ten days at 850 °C in sealed evacuated silica tubes. The product seems not to be moisture‐sensitive as long as direct contact to oxygen is avoided. It even occurs single‐crystalline as greenish amber‐colored platelets with triangular cross‐section when equimolar amounts of CsBr are used as fluxing agent. Nd 2 S 2 Te (trigonal, P 3 m1; a = 461.06(4), c = 769.54(7) pm; V m = 85.314(9) cm 3 /mol, Z = 1) crystallizes with the Ce 2 O 2 S‐type structure and contains Nd 3+ cations in capped trigonal anti‐ prismatic coordination of four S 2– (d(Nd 3+ –S 2– ) = 277 (3 ×) and 285 pm, 1 ×) and three Te 2– anions (d(Nd 3+ –Te 2– ) = 336 pm, 3 ×). Another description emphasizes CdI 2 ‐analogous layers of the composition $^2_\infty$ {[(Te 2– )(Nd 3+ ) 6/3 ] 4+ } where [TeNd 6 ] octahedra share six of their twelve edges. These cationic layers are piled up parallel to (001) and their cross‐linkage is achieved by interstitial S 2– anions in tetrahedral coordination of Nd 3+ . Thereby cationic layers of the type $^2_\infty$ {([(S 2– )(Nd 3+ ) 4/4 ] + ) 2 } are formed likewise, resulting from the condensation of [SNd 4 ] tetrahedra via three of their six edges.