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Sustitución de ligando fotoinducida reversible en un complejo de cromo luminiscente
Narayan Sinha1,2, Joël Wellauer1, Tamar Maisuradze3
1Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland.
Journal of the American Chemical Society
|April 8, 2024
Resumen
Los investigadores desarrollaron un nuevo complejo de cromo que libera y vuelve a unir ligandos al exponerse a la luz. Esta foto-disociación reversible y la re-coordinación ofrece información sobre los materiales de auto-curación y las aplicaciones de foto-cambio.
Área de la Ciencia:
- Química inorgánica
- La fotoquímica
- Ciencias de los materiales
Sus antecedentes:
- La quimioterapia fotoactivada (PACT, por sus siglas en inglés) utiliza la disociación por luz de ligandos de complejos metálicos.
- Las investigaciones actuales de PACT se centran a menudo en metales pesados como el rutenio (II).
- La disociación del ligando fotoinducida es típicamente irreversible.
Objetivo del estudio:
- Informar de un complejo de metales de transición de primera fila que muestre disociación de ligando fotoinducida reversible y re-coordinación espontánea.
- Investigar el mecanismo de disociación de ligandos inducida por la luz en complejos de cromo.
- Explorar aplicaciones potenciales en materiales de conmutación y autocuración.
Principales métodos:
- Síntesis de un complejo de cromo ((0) con quelatos de tridentato de tipo escorpionato.
- Estudios de fotoexcitación con varios disolventes (THF, dioxano, tolueno y ciclohexano).
- Espectroscopia de absorción UV y simulaciones químicas cuánticas.
Principales resultados:
- Descoordinación del ligando de arilisocianuro inducida por la fotoexcitación y coordinación del disolvente en THF y dioxano.
- La disociación del ligando fue dependiente del disolvente, con un efecto mínimo en el tolueno y el ciclohexano.
- La coordinación espontánea del ligando de arilisocianuro ocurrió en una escala de tiempo de milisegundos.
- El mecanismo implica la disociación del ligando fotoinducida de un estado de transferencia de carga de metal a ligando.
Conclusiones:
- El estudio presenta el primer complejo de metales de transición de primera fila con disociación y coordinación de ligandos fotoinducidos reversibles.
- Los hallazgos ofrecen información sobre los mecanismos de autocuración y la lucha contra la fotodegradación.
- El complejo es relevante para aplicaciones en el intercambio fotográfico y el almacenamiento de información fotoquímica.
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