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Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Homoatomic stella quadrangula [Tl8]6- en Cs18Tl8O6, la interacción del acoplamiento espín-órbita y la distorsión de
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
Resumen
Se sintetizó y caracterizó un nuevo óxido de talio y cesio, Cs(18)Tl(8)O(6). Los cálculos relativistas revelan que su diamagnetismo surge del acoplamiento de espín-órbita que influye en el anión del cúmulo estelar tetraédrico [Tl(8) ](6-).
Área de la Ciencia:
- Química del estado sólido.
- Síntesis inorgánica en síntesis inorgánica.
- Ciencia de los materiales computacionales Ciencia de los materiales computacionales.
Sus antecedentes:
- Los óxidos de talio y cesio representan una clase de compuestos con estructuras complejas.
- Comprender la estructura electrónica de los aniones de racimo es crucial para predecir las propiedades de los materiales.
- Estudios previos habían identificado grupos isoelectrónicos con diferentes geometrías, como Cs(8)Tl(8)O.O.
Objetivo del estudio:
- Para sintetizar y caracterizar el nuevo compuesto Cs(18)Tl(8)O(6).
- Para investigar la estructura electrónica del anión del racimo [Tl(8) ](6-) dentro de Cs(18) Tl(8) O(6).
- Para dilucidar el papel del acoplamiento espín-órbita en el comportamiento diamagnético observado.
Principales métodos:
- Síntesis de Cs(18)Tl(8)O(6) a partir del binario CsTl y Cs(2)O.
- Difracción de rayos X monocristalino para la determinación estructural.
- Cálculos de la teoría funcional de densidad relativista (DFT), incluido el acoplamiento de espín-órbita.
Principales resultados:
- Cs(18) Tl(8) O(6) se cristaliza en una nueva estructura cúbica (grupo espacial I23).
- El compuesto contiene un anión de racimo tetraédrico en forma de estrella [Tl(8)](6-).
- Los cálculos relativistas escalares indicaron un sistema de caparazón abierto, pero los cálculos de acoplamiento de órbita de espín revelaron una estructura electrónica de caparazón cerrado, consistente con el diamagnetismo.
Conclusiones:
- El diamagnetismo de Cs(18)Tl(8)O(6) es una consecuencia directa de los efectos de acoplamiento de órbita de espín en el cúmulo [Tl(8)](6-).
- El cúmulo estelar tetraédrico representa un nuevo motivo estructural en comparación con el cúmulo paralelepípedo previamente observado.
- Los efectos relativistas son esenciales para describir con precisión las propiedades electrónicas de tales sistemas de elementos pesados.
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