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Au99(SPh) 42 nanomoléculas: conversión inducida por el ligando tiolato aromático de Au144 ((SCH2CH2Ph) 60

Praneeth Reddy Nimmala¹, Amala Dass

¹Department of Chemistry and Biochemistry, University of Mississippi , Oxford, Mississippi 38677, United States.

Journal of the American Chemical Society

|November 27, 2014

Resumen

Los investigadores sintetizaron una nueva nanomolécula de oro, Au99 ((SPh) 42), a partir de Au144 ((SCH2CH2Ph) 60 mediante el uso de tiofenol. Esta formación de nanomoleculas estables está influenciada por la aromaticidad del ligando, no por su volumen.

Área de la Ciencia:

* Ciencia de los nanomateriales Ciencia de los nanomateriales
* Química Inorgánica y Química Inorgánica.
* Química de las superficies

Sus antecedentes:

* La nanomolécula de oro Au144(SR)60 exhibe una alta estabilidad en diversas condiciones.
* Comprender la reactividad y las vías de transformación de las nanomoléculas de oro es crucial para el desarrollo de nuevos materiales.

Objetivo del estudio:

* Para sintetizar y caracterizar una nueva nanomolécula de oro, Au99(SPh) 42, de un precursor conocido.
* Investigar el mecanismo de reacción y los factores que influyen en la transformación de Au144 (((SR) 60 en especies de oro más pequeñas.
* Para explorar la estabilidad y las propiedades de la recién sintetizada nanomolécula Au99(SPh) 42.

Principales métodos:

* Síntesis de Au99 (((SPh) 42 por reacción de Au144 (((SCH2CH2Ph) 60 con el tiofenol.
* Espectrometría de masas por electrospray de alta resolución (ESI-MS) para la determinación de fórmulas moleculares y el monitoreo de reacciones.
* Caracterización de las propiedades ópticas y electroquímicas de la nanomolecula resultante.
* Experimentos de control utilizando varios ligandos de tiol con diferentes sustituyentes y propiedades estéricas.

Principales resultados:

* Síntesis exitosa de la nanomolécula de oro protegida por el tiolato aromático Au99(SPh) 42.
* Se ha demostrado la reactividad de Au144 ((SCH2CH2Ph) 60 con tiofenol para obtener una especie más pequeña y estable de 99 átomos de oro.
* ESI-MS permitió un monitoreo de alta resolución sin precedentes de la conversión de tamaño de 144 átomos a 99 átomos.
* La aromaticidad del ligando, específicamente la unión directa del grupo fenilo al tiol, se identificó como el factor clave para la conversión de Au144 a Au99, no el volumen del ligando.

Conclusiones:

* La reacción de Au144 (((SCH2CH2Ph) 60 con tiofenol proporciona una nueva vía para sintetizar la nanomolécula Au99 (((SPh) 42 estable.
* La aromaticidad del ligando tiol juega un papel crítico en la conversión de tamaño de las nanomoléculas de oro.
* ESI-MS de alta resolución es una herramienta poderosa para estudiar la dinámica de reacción de las nanopartículas y la evolución del tamaño.

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