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Cintas de porfirina totalmente conjugadas con bandas de absorción electrónica que llegan hasta el infrarrojo
1Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Science (New York, N.Y.)
|July 7, 2001
Resumen
La oxidación catalizada por escandio (III) creó eficientemente zinc ligado (II) -oligoiporfirinas. Estas matrices de porfirina pi-conjugadas muestran un desplazamiento al rojo de la absorción y brechas de baja excitación, lo que sugiere un potencial como cables moleculares.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- Ciencia de los materiales Ciencia de los materiales.
- Química orgánica es la química orgánica.
Sus antecedentes:
- Las matrices de porfirina son cruciales para el desarrollo de nuevos materiales electrónicos.
- El control del enlace y la conjugación en los oligómeros de porfirina es clave para afinar sus propiedades.
Objetivo del estudio:
- Para sintetizar nuevas, zinc en forma de cinta fundida (II) -oligoiporfirinas.
- Investigar el impacto del aumento de las unidades de porfirina en las propiedades electrónicas y ópticas.
- Para explorar el potencial de estos oligómeros como cables moleculares.
Principales métodos:
- La oxidación catalizada por escandio (III) de matrices de zinc (II) -porfirina ligadas al meso-meso mediante el uso de 2,3-dicloro-5,6-diciano-1,4-benzoquinona (DDQ).
- Síntesis de las oligoiporfirinas hasta los dodecameros.
- Análisis espectroscópico (absorción UV-Vis) y mediciones electroquímicas (potenciales de oxidación).
Principales resultados:
- Formación eficiente de las oligoiporfirinas de zinc ((II) -oligoiporfirinas triple ligadas (rendimiento del 62-91%).
- Se observaron bandas de absorción extremadamente desplazadas hacia el rojo debido a una extensa conjugación pi.
- Demostró una brecha de excitación progresivamente decreciente con el aumento de las unidades de porfirina, alcanzando un pico para el dodecamero.
- Mostró disminuir progresivamente los potenciales de oxidación de un electrón con el aumento de las unidades de porfirina.
Conclusiones:
- Las matrices de porfirina sintetizadas en forma de cinta fundida poseen sistemas electrónicos altamente conjugados.
- Las propiedades observadas, incluida la absorción con desplazamiento al rojo y los potenciales de oxidación sintonizables, los convierten en candidatos prometedores para aplicaciones de alambre molecular.
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