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Control de las propiedades electrónicas de los cromóforos en el infrarrojo cercano a través de la alineación orbital
Nicole M Mews1, Andreas Berkefeld1, Gerald Hörner2
1Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen , Auf der Morgenstelle 18, 72076 Tübingen, Germany.
Journal of the American Chemical Society
|February 11, 2017
Resumen
Los investigadores desarrollaron nuevos tintes de infrarrojo cercano (NIR) utilizando complejos de platino. La orientación del ligando controla el acoplamiento electrónico, lo que permite transiciones NIR distintas para aplicaciones de colorantes a medida.
Área de la Ciencia:
- Ciencias de los materiales
- Química inorgánica
- La fotoquímica
Sus antecedentes:
- Los complejos de metales de transición con ligandos radicales pueden mostrar transiciones electrónicas de baja energía en el espectro del infrarrojo cercano (NIR).
- La energía y la intensidad de las bandas NIR son altamente sensibles al acoplamiento electrónico dentro del cromóforo.
Objetivo del estudio:
- Presentar una nueva estrategia para la creación de tintes NIR espectroscópicamente distintos.
- Para correlacionar el grado de acoplamiento electrónico con la orientación relativa del ligando radical y los orbitales metálicos en complejos de platino de cáscara abierta.
Principales métodos:
- Síntesis de complejos de platino de cáscara abierta con un ligando de 1,4-terfenilditiofenol.
- Modulación de la alineación orbital ligando/metal utilizando donantes auxiliares de fosfina.
- Análisis espectroscópico para caracterizar las transiciones NIR.
Principales resultados:
- Demostró una correlación entre la alineación orbital y el acoplamiento electrónico, lo que lleva a perfiles de absorción NIR distintos.
- Se ha logrado la formación selectiva de estructuras de clase II-III (localizadas por electrones) o de clase III (delocalizadas).
- Se observaron distintas transiciones NIR a 6500 cm-1 y 4000 cm-1 correspondientes a las diferentes estructuras electrónicas.
Conclusiones:
- El enfoque presentado permite el diseño racional de tintes NIR con propiedades espectroscópicas ajustables.
- El control de la alineación orbital es un factor clave en la modulación del acoplamiento electrónico y las características de absorción NIR.
- Estos hallazgos ofrecen una vía para nuevos tintes NIR para diversas aplicaciones.
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