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Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
Las firmas electrónicas y vibratorias del grupo Au102 ((p-MBA) 44
Eero Hulkko1, Olga Lopez-Acevedo, Jaakko Koivisto
1Nanoscience Center, Department of Chemistry, P.O. Box 35, FI-40014 University of Jyväskylä, Finland.
Journal of the American Chemical Society
|February 26, 2011
Resumen
Se midió y calculó la absorción óptica de los nanocúmulos de oro, revelando las transiciones electrónicas clave. El intercambio de ligandos no afectó las propiedades electrónicas centrales, proporcionando puntos de referencia para futuras aplicaciones de nanocluster.
Área de la Ciencia:
- Nanotecnología La nanotecnología es la nanotecnología.
- Ciencia de los materiales Ciencia de los materiales.
- Química Física es la química física.
Sus antecedentes:
- Los nanocúmulos de oro son prometedores para varias aplicaciones.
- Comprender sus propiedades ópticas es crucial para el desarrollo.
- El ácido para-mercaptobenzoico (p-MBA) es un ligando común para los nanocúmulos de oro.
Objetivo del estudio:
- Para medir y calcular el espectro de absorción óptica de un nanocúmulo de oro específico, Au{102}{p-MBA}{44}.
- Para comparar los resultados experimentales con cálculos teóricos utilizando la teoría funcional de la densidad dependiente del tiempo (TD-DFT).
- Para investigar el efecto del intercambio de ligandos en las propiedades ópticas del nanocúmulo.
Principales métodos:
- Espectroscopia de absorción óptica a través de un amplio rango de energía (0.056.2 eV).
- Purificación de muestras de nanocluster para mediciones de la fase sólida y de la fase de solución.
- Cálculos teóricos utilizando TD-DFT en el régimen de respuesta lineal.
- Experimentos de intercambio de ligandos con el glutatión.
Principales resultados:
- Los coeficientes de absorción molar experimentales y calculados en la región NIR-vis se acordaron dentro de un factor de 2.
- Se observaron características de absorción entre 1,5 y 3,5 eV.
- El inicio de las transiciones electrónicas se determinó experimentalmente a 0,45 ± 0,05 eV, coincidiendo estrechamente con el 0,55 eV calculado.
- Las vibraciones de ligandos contribuyeron a las características IR por debajo de las transiciones electrónicas.
- El intercambio parcial de ligandos con glutatión no alteró el inicio de la transición electrónica.
Conclusiones:
- El estudio proporciona una caracterización espectroscópica completa del nanocluster Au.
- Los datos experimentales y teóricos de absorción óptica muestran un buen acuerdo.
- Las propiedades electrónicas del núcleo metálico son robustas contra el intercambio de ligandos, lo que indica estabilidad.
- Estos hallazgos sirven como puntos de referencia para futuras investigaciones sobre la manipulación y las aplicaciones de nanoclusters.
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