Go toArchive
Browse byFacets
Bookbag ( 0 )
'Selenides' in keywords
Results  2 Items
Sorted by   
Publication Year
2001 (2)
1Author    Falk Lissner, FrankA. Weber, Thomas SchleidRequires cookie*
 Title    Drei Formen des Samarium(III)-Sulfidselenids Sm2S2_JC Se1+A . (0,1 < x < 0,2) Three Types of the Samarium(III) Sulfide Selenide Sm2S2_ vSe1+JC (0.1 < x < 0.2)  
 Abstract    Single crystals of Sm2 S2 -jSe1+x (0.1 < x < 0.2) have been obtained for the first time through the oxidation of KSm2Cl5 with an excess of sulfur and selenium in equimolar amounts at 850 °C after seven days in evacuated silica tubes. They emerged as almost black, in thin layers deep red, lath-shaped needles (A and U type, respectively) as well as red, bead-shaped polyhedra (C type) of the gross chemical composition Sm2S2Se according to X-ray structure analyses. A much simpler method of synthesis is based on the direct fusion of the elements (samarium, sulfur and selenium) in appropriate molar ratios (2:2:1) in the presence of NaCl as a flux under otherwise analogous conditions (silica tubes, 7 d, 850 °C). A-Sm2 S1.82Se1.18 crystallizes orthorhombically (a = 753.1(3), b = 401.9(1), c = 1565.8(6) pm, Z = 4) in the space group Pnma with the a-G d2 S3-type structure. Two crystallographically different Sm3+ cations are coordinated by eight (Sm l) and seven (Sm2) Ch2~ anions (S2_ and Se2 -) as bi-and monocapped trigonal prisms, respectively. C-Sm2S! 90 Se, 10 adopts the cubic 7 -Ce2 S3-type structure (/ 43d; a = 858.7(2) pm, Z = 5.333) with trigon-dodecahedrally coordinated Snr + cations (CN = 8). Finally, U-Sm2S L84Se116 with the orthorhombic U2S3-type structure (Pnma; a = 1105.3(6), b = 399.2(1), c = 1074.0(5) pm, Z = 4) exhibits two crystallographically different Sm3+ cations again, which are coordinated by seven (Sml) and seven plus one (Sm2) Ch2_ anions, respectively. The preferential occupation of S _ and Se2-anions at only one in the C-type, but three anionic sites each in the A-and U-type crystal structures of Sm2 S2 -*Se1+;c (0 . 1 < x < 0 .2) is discussed. 
  Reference    Z. Naturforsch. 56b, 990—996 (2001); eingegangen am 14. Juni 2001 
  Published    2001 
  Keywords    Samarium, Sulfides, Selenides 
  Similar Items    Find
 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-0990.pdf 
 Identifier    ZNB-2001-56b-0990 
 Volume    56 
2Author    NorbertA. Harringer, Andreas Kolb, KurtO. KleppRequires cookie*
 Title    Na2ZrSe3, ein neues Chalcogenometallat(IV) mit Schichtstruktur Na2ZrSe3, a New Chalcogenometallate(IV) with a Layered Structure  
 Abstract    Orange red crystals of Na2ZrSe3 were obtained by the reaction of Na2Se, Zr and Se at 800 °C. The new compound is monoclinic, s. g. C2/m with a = 6.952(2), b = 12.01(1), c = 7.257(2) A, ß = 108.81(2)°, Z = 4. Its crystal structure was determined from single crystal diffractometer data (Mo-KQ-radiation) and refined to a conventional R of 0.016. It is characterized by layers based on a distorted ccp packing of Se-atoms where all metal atoms occupy octahedral voids in an ordered fashion. Zr atoms are located on the nodes of a 6 3-net forming CrCl3 type selenozirconate layer (d(Zr-Se) = 2.702 A). 
  Reference    Z. Naturforsch. 56b, 1322—1324 (2001); eingegangen am 30. August 2001 
  Published    2001 
  Keywords    Complex Chalcogenides, Selenides, Zirconium 
  Similar Items    Find
 TEI-XML for    default:Reihe_B/56/ZNB-2001-56b-1322.pdf 
 Identifier    ZNB-2001-56b-1322 
 Volume    56