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Espectroscopia y estructura electrónica de las ftaalocianinas de zinc con deficiencia de electrones
Steven P Keizer1, John Mack, Barbara A Bench
1Department of Chemistry, The University of Western Ontario, London, Ontario, N6A 5B7 Canada.
Journal of the American Chemical Society
|June 5, 2003
Resumen
La introducción de grupos perfluoroalquilo en las ftaalocianinas de zinc mejora su estabilidad y propiedades electrónicas. Esta modificación previene la fotooxidación y estabiliza los aniones radicales, haciéndolos altamente deficientes en electrones.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química orgánica es la química orgánica.
- La espectroscopia es una técnica de espectroscopia.
Sus antecedentes:
- Las ftaalocianinas son compuestos macrocíclicos versátiles con aplicaciones en varios campos.
- La modificación de las estructuras de ftaalocianina puede ajustar sus propiedades electrónicas y ópticas.
- La sustitución de grupos perfluoroalquilo es una estrategia para mejorar la estabilidad química y fotofísica.
Objetivo del estudio:
- Para investigar las propiedades espectroscópicas y electroquímicas de una nueva ftaalocianina de zinc fluorado.
- Comprender el impacto de los grupos perfluoroalquilo en la estructura electrónica y la estabilidad de las ftaalocianinas.
- Para caracterizar las especies de aniones radicales de la ftaalocianina de zinc fluorado.
Principales métodos:
- Absorción de rayos UV visibles y espectroscopia de dicroísmo magnético circular (MCD).
- Ionización por electrospray (ESI) y espectrometría de masas MALDI-TOF.
- Voltametría de pulso cíclico y diferencial.
- Complete los cálculos teóricos utilizando las técnicas INDO/S y la Teoría Funcional de Densidad (DFT).
Principales resultados:
- La sustitución de los dieciséis átomos de hidrógeno por ocho grupos F y ocho grupos i-C ((3) F ((7) causó un desplazamiento al rojo en las transiciones Q y pi --> pi.
- La brecha HOMO-LUMO se redujo, lo que indica propiedades electrónicas alteradas.
- La ftaalocianina fluorada impidió la fotooxidación del anillo y estabilizó inusualmente las especies de aniones radicales.
- La fuerte naturaleza de retirada de electrones de los sustituyentes hizo que el complejo tuviera una alta deficiencia de electrones.
Conclusiones:
- La introducción de un grupo perfluoroalquilo modifica significativamente las propiedades electrónicas y espectroscópicas de la ftaalocianina.
- La ftaalocianina de zinc fluorado resultante exhibe una mayor estabilidad, particularmente por su anión radical.
- La naturaleza deficiente en electrones de la ftaalocianina modificada abre caminos para nuevas aplicaciones.
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