Lanthanides reduce mixtures of I(2) and PhSeSePh in THF, and the resultant heteroligand mixture reacts further with elemental Se in pyridine to give (THF)(6)Ln(4)I(2)(SeSe)(4)(mu(4)-Se).THF (Ln = Tm, Ho, Er, Yb). These selenium rich clusters contain a square array of Ln(III) ions connected through a single (mu(4)-Se) ligand. There are two I(-) ligands coordinating nonadjacent Ln(III) ions on the side of the cluster opposite the (mu(4)-Se), and the edges of the square are bridged by mu(2)-SeSe groups. The electronic spectrum of the Yb compound contains two absorption maxima that can tentatively be assigned as Se(2-) to Yb and SeSe to Yb charge-transfer absorptions, by comparison with the featureless absorption spectra of the Tm, Ho, and Er derivatives. With a 1/1/1/1 Yb/I/Ph(2)S(2)/Se stoichiometry, chalcogen rich compounds are not obtained, but instead, in Yb chemistry, the selenido cluster (THF)(10)Yb(6)Se(6)I(6) can be isolated in 51% yield. The molecular structure of this compound contains a Yb(4)Se(4) cubane fragment, with an additional Yb(2)Se(2) layer capping one face of the cube. Each Yb coordinates a terminal I(-). This intensely colored compound also has an absorption maximum in the visible spectrum. Upon thermolysis, the selenium rich compounds give Ln(2)Se(3) that is free of iodide contamination.
High-Pressure Syntheses of Lanthanide Polysulfides and Polyselenides<i>LnX</i><sub>1.9</sub>(<i>Ln</i>= Gd-Tm,<i>X</i>= S, Se)
作者:Carola J. Müller、Ulrich Schwarz、Thomas Doert
DOI:10.1002/zaac.201200304
日期:2012.12
vacant. This resembles a √5×√5 × 2 superstructure of the ZrSSi aristotype. Structural relationships to the aristotype and the related lanthanide polychalcogenides LnX2–δ (Ln = La–Tm, X = S–Te, δ = 0 – 0.3) are discussed. The samples synthesized under high-pressure conditions (p > 1 GPa) decompose slowly under release of sulfur or selenium at ambient conditions. The crystal structure of a partially degraded
通过高压高温合成制备了从钆到铥的镧系金属的多硫化物LnS1.9和聚硒化物LnSe1.9。该化合物在空间群P42/n(No.86)中采用四方CeSe1.9结构类型,晶格参数为8.531 A ≤ a ≤ 8.654 A,硫化物的晶格参数为15.563 A ≤ c ≤ 15.763 A,8.869 A ≤ a 6 ≤ 9.07 A 和 16.367 A ≤ c ≤ 16.611 A 硒化物。原子模式由褶皱双板 [LnX]+ 和具有十个可能的硫属元素位置的平面硫属化物层组成,其中八个被硫属元素原子占据,形成双核 X22-二价阴离子,一个被单个 X2-离子占据,一个剩余空位。这类似于 ZrSSi 亚型的 √5×√5×2 上层结构。与贵族型和相关镧系元素多硫族化物 LnX2-δ 的结构关系(Ln = La-Tm,X = S-Te,δ = 0 – 0.3) 进行了讨论。在高压条件 (p > 1 GPa)
New Quaternary Chalcogenides BaLnMQ3 (Ln = Rare Earth or Sc; M = Cu, Ag; Q= S, Se)
作者:Ping Wu、Amy E. Christuk、James A. Ibers
DOI:10.1006/jssc.1994.1177
日期:1994.6
Some new quaternary compounds of the type BaLnMQ3 (Ln = rare earth or Sc; M = Cu, Ag; Q = S, Se) have been synthesized by the reaction of the constituent binary chalcogenides and elements at 1000°C. The crystalstructures of two of these compounds have been determined by single-crystal X-ray diffraction techniques and are isostructural. Crystal data: BaErCuS3—space group D172h —Cmcm, M= 464.32, Z =