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Un ciclófano de hexa-peri-hexabenzocoroneno: una adición a la caja de herramientas para la electrónica molecular

Mark D Watson¹, Frank Jäckel, Nikolai Severin

¹Max-Planck-Institute for Polymer Research, Postfach 3148, D-55021 Mainz, Germany.

Journal of the American Chemical Society

|February 5, 2004

Resumen

Los nuevos ciclofanos encapsulan grandes hidrocarburos aromáticos policíclicos, formando fases de cristal líquido. Estas moléculas exhiben un comportamiento eléctrico parecido a un diodo, allanando el camino para la electrónica molecular.

Área de la Ciencia:

Química supramolecular de las moléculas.
Ciencia de los materiales Ciencia de los materiales.
Electrónica orgánica y electrónica orgánica.

Sus antecedentes:

Los hidrocarburos aromáticos policíclicos (HAP) como el hexa-peri-hexabenzocoroneno (HBC) son cruciales para la electrónica orgánica.
La encapsulación de HAP en estructuras ciclófanas puede controlar su autoensamblaje y propiedades electrónicas.

Objetivo del estudio:

Para sintetizar y caracterizar los nuevos ciclofanos que contienen el mayor HAP conocido (HBC).
Investigar el comportamiento de autoensamblaje y las propiedades electrónicas de estos nuevos complejos ciclófano-PAH.

Principales métodos:

Metátesis de olefinas de cierre de anillo intermolecular para la síntesis de ciclófano.
Calorimetría de barrido diferencial (DSC), microscopía óptica y difracción de rayos X de ángulo ancho (WAXD) para el análisis de mesofase.
Microscopía de túnel de barrido (STM) y espectroscopia de túnel de barrido (STS) para imágenes moleculares y caracterización eléctrica.

Principales resultados:

Síntesis exitosa de ciclofanos con unidades de HBC a través de la metátesis de olefinas.
Formación de mesofasas de cristales líquidos columnares termotrópicos, similares a las HBC monoméricas.
Disposición cara a cara de los discos de HBC dentro de los ciclófanos con un ligero desplazamiento lateral.
Observación del comportamiento eléctrico parecido a un diodo en moléculas individuales a través de STS.

Conclusiones:

Los ciclofanos sintetizados efectivamente encapsulan grandes HAP y se auto-ensamblan en fases ordenadas de cristales líquidos.
Las propiedades eléctricas de una sola molécula imitan las de los discos HBC individuales, lo que demuestra el potencial de los dispositivos electrónicos moleculares.
Este trabajo proporciona una base para explorar complejos moleculares dinámicos en aplicaciones eléctricas.

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