Structure du disulfure de lanthane et de cuivre

Abstract

Abstract. CuLaS2, monoclinic, P2Jb, a = 6.646 (2), b = 6.938 (2), c = 7.325 (2)A, ~= 98.73 (2)°, Z = 4, d m = 5.29 (8), d x = 5.3 Mg m -3. The structure has been solved by direct methods and refined by leastsquares methods to a final R value of 0.063 for 999 reflexions. The structure is built up of sheets parallel to the b and c axes. One sheet is made of (LaaS) tetrahedra, and has the composition (LaS); the second sheet is formed by (CuS4) tetrahedra arranged in pairs, which alternate with pairs of empty tetrahedra.

La2CuS4: A Lanthanum Copper Sulfide with Discrete Anion Triples [S3Cu⋅⋅⋅SS⋅⋅⋅CuS3]12− Based on La4[Cu2S6(S2)]

“…The addition of CsBr as fluxing agent promoted the crystal growth significantly, but LaS 2 [7] and LaCuS 2 [8] were formed as undesired by-products. In the presence of CsI as fluxing agent, the yield of La 2 CuS 4 increased, although no pure product was obtained with this method.…”

“…The X-ray singlecrystal structure analysis [6] indicates that these units comprise two almost planar [CuS 3 [7] the distances between the Cu + cations and the three S 2À anions range from 224 to 226 pm and are shorter than those known for copper in tetrahedral arrangements (e.g. CuLaS 2 : [8] average distance d (Cu-S) = 243 pm). They rather match those found for copper with triangular coordination (average distance d (Cu-S) = 233 pm in Cu 2 S [4] ).…”

Syntheses, Structure, Magnetism, and Optical Properties of the Ordered Interlanthanide Copper Chalcogenides Ln2YbCuQ5 (Ln = La, Ce, Pr, Nd, Sm; Q = S, Se): Evidence for Unusual Magnetic Ordering in Sm2YbCuS5

“…In group one phases, there are no Q-Q (Q = S, Se, Te) interactions. These compounds have been generally synthesized at relatively high temperatures as thermodynamically stable products, which include LnCuQ 2 (Ln = rare-earth; Q = S, Se, Te), [1][2][3][4][5][6][7][8][9][10][11] slightly tilting the furnaces. Powder X-ray diffraction measurements were used to confirm phase purity by comparing the powder patterns calculated from the single-crystal X-ray structures with the experimental data.…”

CuYS2: Ein ternäres Kupfer(I)-Yttrium(III)-Sulfid mit Ketten∞1{[Cu(S1)3/3(S2)1/1]3-}cis-kantenverknüpfter [CuS4]7--Tetraeder

“…r i (Li + ) = 76, r i (Cu + ) = 77 pm fu È r CN = 6) [4] weist die Kristallstruktur von CuScS 2 [5] zwar noch immer trigonal-antiprismatisch koordiniertes Sc 3+ (r i = 75 pm, CN = 6) [4] auf, dagegen besetzt Cu + nun tetraedrische Lu È cken innerhalb der hexagonal-dichtest gepackten S 2± -Teilstruktur. Dies gilt bezu È glich der Cu + -Kationen auch fu È r den Aufbau von CuLaS 2 [6], wa È hrend der gro È ûere Ionenradius der La 3+ -Kationen (r i = 110 pm, CN = 7) [4] [10] (durch Aktivierung der SiO 2 -Gefa È ûwand unter dem Einfluû basischer Oxidkontamination). Ein tauglich erscheinender Einkristall wurde unter Paraffino È l ausgesucht und auf einem Fla È chenza È hler (vgl.…”