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Un grupo de tamaño mágico de CdS quiral con cristalización sesgada enantioméricamente
Cheng Xu1, Zhenyi Zhang2, Zheng Zhou1
1Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.
Journal of the American Chemical Society
|May 15, 2025
Resumen
Los grupos de tamaño mágico de sulfuro de cadmio quiral (MSC) se sintetizaron a través del intercambio catiónico. Estos MSC quirales se autoensamblan en superestructuras quirales, exhibiendo dicroísmo circular debido a su estructura atómica única.
Área de la Ciencia:
- Ciencias de los materiales
- Nanotecnología
- La cristalografía
Sus antecedentes:
- Los nanocristales semiconductores binarios suelen exhibir redes atómicas achirales.
- Las especies metastables y transitorias en las primeras etapas de formación, particularmente los grupos de tamaño mágico (MSC), pueden poseer quiralidad.
- Estas especies quirales pueden autoensamblarse en superestructuras quirales de orden superior.
Objetivo del estudio:
- Para demostrar la presencia de quiralidad en los nanocristales semiconductores durante su formación.
- Sintetizar y caracterizar las MSCs quirales de sulfuro de cadmio.
- Para investigar el autoensamblaje de las MSCs quirales en superestructuras quirales.
Principales métodos:
- Proceso de intercambio catiónico a temperatura ambiente.
- Cristalografía de rayos X de un solo cristal para la determinación de la estructura atómica.
- Las mediciones de respuesta quiróptica.
Principales resultados:
- Un grupo simétrico de sulfuro de cobre fue convertido en MSC de sulfuro de cadmio enantiomérico, (+) / ((-) [Cd28S17].
- Los [Cd28S17] MSC poseen una nueva configuración antisupertetraédrica.
- Las MSC se cristalizan de una manera enantioméricamente sesgada, no como una mezcla racémica.
- Se observaron respuestas quirópticas claramente opuestas, lo que indica una actividad de dicroísmo circular genuina.
Conclusiones:
- La quiralidad puede surgir en los nanocristales semiconductores binarios durante la formación, específicamente en el régimen MSC.
- Las CdS MSCs quirales sintetizadas se autoensamblan en superestructuras quirales con propiedades quirópticas observables.
- El dicroísmo circular observado está directamente relacionado con la estructura atómica quiral única de las CdS MSC.
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