ホモアトミック・ステラ・クワッドランジュラ [Tl8]6- in Cs18Tl8O6,スピン・軌道結合の相互作用,そしてヤーン・テラー歪み
Ulrich Wedig1, Vyacheslav Saltykov, Jürgen Nuss
1Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany.
Journal of the American Chemical Society
|August 14, 2010
まとめ
新しいセシウムタリウム酸化物,Cs(18) Tl(8) O(6) が合成され,特徴づけられました. 相対論的計算により,その二磁性性は[Tl(8) ](6-) の四面体星群アニオンに影響を与えるスピン軌道結合から生じていることが明らかになった.
科学分野:
- 固体化学 固体化学
- 無機合成 無機合成
- コンピューティング・マテリアル・サイエンス
背景:
- セシウムタリウム酸化物は,複雑な構造を持つ化合物のクラスを表しています.
- クラスターアニオンの電子構造を理解することは,材料の性質を予測するために重要である.
- 以前の研究では,Cs(8) Tl(8) O.O.のような異なる幾何学を持つアイソエレクトロニッククラスターを特定しました.
研究 の 目的:
- 新しい化合物Cs(18)Tl(8)O(6) を合成し,特徴づけること.
- Cs(18) Tl(8) O(6) の内部にある[Tl(8) ](6-) クラスターアニオンの電子構造を調査する.
- 観測された二磁性行動におけるスピン軌道結合の役割を明らかにする.
主な方法:
- バイナリCsTlとCs(2) O.からCs(18) Tl(8) O(6) の合成
- 構造的決定のための単一結晶X線 difraktion.
- 相対性密度関数理論 (DFT) の計算,スピン軌道結合を含む.
主要な成果:
- Cs(18) Tl(8) O(6) は新しい立方体構造 (空間群I23) で結晶化する.
- この化合物は,四面体星形 [Tl(8) ](6-) クラスターアニオンを含んでいる.
- スキャラ相対論的計算は,オープンシェル系を示したが,スピン軌道結合計算は,ダイアマグネティズムと一致する閉鎖シェルの電子構造を明らかにした.
結論:
- Cs(18) Tl(8) O(6) の二磁気性は,[Tl(8) ](6-) 群集におけるスピン軌道結合効果の直接的な結果である.
- テトラエドール星団は,以前に観測されたパラレレピペッド星団と比較して,新しい構造的モチーフを表しています.
- 相対論的効果は,このような重元素システムの電子特性を正確に記述するために不可欠です.
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