Synthese kristalliner Chalkogenide in ionischen Flüssigkeiten

Abstract

Kristalline Chalkogenide gehören zu den vielversprechendsten Materialklassen. Außer dicht gepackten Festkörperstrukturen können sie auch Arrangements molekularer Cluster und Netzwerke mit hohen Porositäten bilden, wie in den so genannten zeotypen Chalkogenidometallaten. Sie zeichnen sich durch große Strukturvielfalt und interessante physikalische Eigenschaften aus. Zusätzlich zu Halbleitereigenschaften findet man Photoleitfähigkeit, Ionenleitfähigkeit, die Möglichkeit zum Moleküleinfang sowie chemische und katalytische Aktivität. Das große Interesse an der Entwicklung neuer und maßgeschneiderter Chalkogenide führte im Laufe der Jahre zu der Suche nach immer neuen und besseren Synthesestrategien. Es lässt sich ein klarer Trend in Richtung niedrigerer Synthesetemperaturen erkennen, was auf ökonomische und ökologische Gründe sowie den Wunsch nach einer besseren Reaktionskontrolle zurückzuführen ist. So kam es auch im Bereich der Chalkogenide zu Anwendungen von ionischen Flüssigkeiten als Designermedium für die Materialsynthese. In diesem Aufsatz fassen wir jüngste Entwicklungen zusammen und geben einen Überblick über verschiedene Familien von Chalkogeniden und deren Eigenschaften.

Polysulfide Coordination Clusters of the Lanthanides

“…[9] Earlier this year,Zhou and co-workers showed that [Tp Me2 Y-(CH 2 Ph) 2 (thf)] (Tp Me2 = hydro-tris(3,5-dimethylpyrazolyl)borate,thf = tetrahydrofuran) can be converted into the yttrium pentasulfide [Tp Me2 Y(k 4 -S 5 )(thf)] in an insertion reaction. [11] To deepen our understanding of the formation of lanthanide polysulfide coordination clusters,wedecided to study the reactivity of sterically demanding divalent lanthanide compounds with elemental sulfur.F or example,E vans and coworkers have shown that the reaction of samarocene [Cp* 2 Sm(thf) 2 ]( Cp* = h 5 -C 5 Me 5 )w ith elemental sulfur results in the trisulfide species [{Cp* 2 Sm} 2 (S 3 )]. In general, molecular and solid-state chalcogenidometalates have interesting physical properties, including semi-and photoconductivity as well as chemical and catalytic activity,and they can be used for ion transport and as molecular traps.…”

“…In general, molecular and solid-state chalcogenidometalates have interesting physical properties, including semi-and photoconductivity as well as chemical and catalytic activity,and they can be used for ion transport and as molecular traps. [11] To deepen our understanding of the formation of lanthanide polysulfide coordination clusters,wedecided to study the reactivity of sterically demanding divalent lanthanide compounds with elemental sulfur.F or example,E vans and coworkers have shown that the reaction of samarocene [Cp* 2 Sm(thf) 2 ]( Cp* = h 5 -C 5 Me 5 )w ith elemental sulfur results in the trisulfide species [{Cp* 2 Sm} 2 (S 3 )]. [7a] As shown here and in previous studies,t he product formation initiated by divalent lanthanide species depends on the steric demand of the ligand.…”

Synthesis of nickel/gallium nanoalloys using a dual-source approach in 1-alkyl-3-methylimidazole ionic liquids

“…We assume that during the dispersion a chemical reaction of the precursors to Ni/Ga clusters occurs. The formation of clusters from metal precursor materials in ionic liquids has been described before, for example, [EMIm][Ni(P 2 S 8 )] [51], [BMMIm] 16 [Sn 24 Se 56 ] [52], [Ru 2 Bi 14 Br 4 ][AlCl 4 ] [53], [Bi 5 (AlCl 4 ) 3 ] [53], [Au(Bi 8 )(AlCl 4 ) 5 ] [54], and [(CuBi 8 )(AlCl 4 )] [55]…”

The Mixed‐Valence Catena‐Heteropolycation (Bi2S2)+

“…ILs are increasingly used in inorganic synthesis in recent years as they allow access to known materials at lower temperatures and often also higher purity compared to conventional synthesis methods. [1][2][3][4][5][6][7][8][9][10][11][12][13] Furthermore, ionic liquids foster the formation of new compounds that have not been accessed in other reaction media or by solvent-free reaction of the constituents. Especially complex ionic species seem to form more readily in ILs.…”