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Efecto de los sustituyentes de la cadena lateral en el autoensamblaje de las moléculas de perileno diimida: control
Kaushik Balakrishnan1, Aniket Datar, Tammene Naddo
1Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA.
Journal of the American Chemical Society
|June 1, 2006
Resumen
La ingeniería de la cadena lateral en las moléculas de perileno diimida dicta la morfología de autoensamblaje. Diferentes cadenas laterales en DD-PTCDI y ND-PTCDI dieron como resultado nanobeltas 1D y nanopartículas 0D, respectivamente, que afectan las propiedades ópticas.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Electrónica orgánica y electrónica orgánica.
- Química supramolecular de las moléculas.
Sus antecedentes:
- Las moléculas de perileno diimida (PTCDI) son cruciales en la electrónica orgánica debido a sus propiedades fotofísicas.
- Controlar el autoensamblaje de los derivados PTCDI es clave para afinar su rendimiento.
- La ingeniería de la cadena lateral ofrece una vía para influir en el empaque molecular y la morfología agregada.
Objetivo del estudio:
- Investigar cómo las diferentes sustituciones de la cadena lateral en las moléculas de PTCDI afectan a su morfología de autoensamblaje.
- Para comparar el comportamiento de autoensamblaje de N,N'-di(dodecilo) -perileno-3,4,9,10-diimida tetracarboxílica (DD-PTCDI) y N,N'-di(nonyldecilo) -perileno-3,4,9,10-diimida tetracarboxílica (ND-PTCDI).
- Comprender la relación entre la estructura molecular, la morfología agregada y las propiedades ópticas.
Principales métodos:
- Síntesis de dos derivados PTCDI con distintas cadenas laterales: DD-PTCDI y ND-PTCDI.
- Caracterización de la morfología de autoensamblaje utilizando microscopía electrónica de barrido (SEM), microscopía electrónica de transmisión (TEM), microscopía de fuerza atómica (AFM) y microscopía de fluorescencia.
- Fabricación de autoensamblajes a través de procesamiento basado en soluciones y recocido por solvente y vapor.
- Investigación de las interacciones moleculares utilizando la absorción UV-vis, la espectroscopia de fluorescencia, la difracción de rayos X y la calorimetría de barrido diferencial (DSC).
Principales resultados:
- DD-PTCDI se autoensambló en nanobeltas unidimensionales (1D), mientras que ND-PTCDI formó nanopartículas de dimensión cero (0D).
- Los nanobeltos de DD-PTCDI exhibieron una alta estabilidad y pudieron ser transferidos a varias superficies.
- Los agregados DD-PTCDI mostraron un desplazamiento al rojo significativo en la emisión (aprox. 30 nm) y una disminución de tres veces en el rendimiento cuántico de emisión en comparación con ND-PTCDI, atribuido a un apilamiento pi-pi más favorable.
- Los agregados DD-PTCDI mostraron una banda de absorción pronunciada en longitudes de onda largas, a diferencia de los agregados ND-PTCDI.
Conclusiones:
- La estructura de la cadena lateral controla críticamente la morfología de autoensamblaje de las moléculas PTCDI, lo que lleva a estructuras de nanopartículas 1D y 0D distintas.
- Las diferencias observadas en la morfología y las propiedades ópticas (cambio de emisión, rendimiento cuántico, absorción) están directamente relacionadas con las variaciones inducidas por la cadena lateral en el apilamiento molecular.
- Estos hallazgos resaltan la importancia de la ingeniería de la cadena lateral para el diseño de materiales basados en PTCDI con características de autoensamblaje y optoelectrónica a medida.
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