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El complejo bis-bario de una mariposa corona el éter como un catalizador supramolecular fototunable
Roberta Cacciapaglia1, Stefano Di Stefano, Luigi Mandolini
1Dipartimento di Chimica and ICCOM CNR-Sezione di Roma, Università La Sapienza, Box 34-ROMA 62, 00185 Roma, Italy. roberta.cacciapaglia@uniroma1.it
Journal of the American Chemical Society
|February 20, 2003
Resumen
La eficiencia catalítica de un complejo bis-bario fue controlada de forma reversible utilizando luz. El catalizador es el catalizador.
Área de la Ciencia:
- Química supramolecular de las moléculas.
- La catálisis de la catálisis.
- La fotoquímica es la fotoquímica.
Sus antecedentes:
- Los derivados de azobenzeno son conocidos por sus propiedades de fotoisomerización.
- Los éteres de la corona pueden formar complejos con iones metálicos, lo que influye en la actividad catalítica.
- El control de los procesos catalíticos con estímulos externos como la luz es un objetivo clave en la química.
Objetivo del estudio:
- Desarrollar un catalizador cuya eficiencia puede ajustarse de forma reversible mediante la luz.
- Para investigar el mecanismo de la modulación de la actividad catalítica inducida por la luz.
- Para lograr la fotorregulación continua de la catálisis.
Principales métodos:
- Síntesis de un complejo de bis-bario que incorpora una unidad de azobenzeno.
- Irradiación fotoquímica para inducir la isomerización cis-trans de la fracción de azobenzeno.
- Monitoreo de la actividad catalítica en la etanólisis básica de los derivados de anilideo.
- Variar la longitud de onda de excitación y el tiempo de irradiación para controlar la actividad del catalizador.
Principales resultados:
- Se logró la conmutación reversible de la eficiencia catalítica entre los estados "ALTO" y "BAJO".
- El isómero cis del catalizador forma un complejo más productivo con el sustrato.
- Se demostró la fotorregulación continua de la actividad catalítica en niveles intermedios.
- La interconversión rápida entre estados fotostacionarios permitió la conmutación repetida dentro de un solo experimento.
Conclusiones:
- El complejo de azobenceno bis-bario actúa como un catalizador con fotointercambio.
- El control fotoquímico sobre la eficiencia catalítica es factible y ajustable.
- Este trabajo ofrece una vía para el desarrollo de sistemas catalíticos sensibles a la luz.
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