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Energética y consecuencias estructurales de la coordinación del ligando axial en las porfirinas de níquel no planas
Yujiang Song1, Raid E Haddad, Song-Ling Jia
1Biomolecular Materials and Interfaces Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA.
Journal of the American Chemical Society
|January 27, 2005
Resumen
El ruffling de porfirina en complejos de níquel (II) disminuye la afinidad de unión de ligando axial. Esta distorsión estructural afecta a los dispositivos moleculares y las funciones biológicas que involucran a las porfirinas de níquel.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- La bioquímica es la bioquímica.
- Química computacional es la química computacional.
Sus antecedentes:
- Las porfirinas de níquel (II) son cruciales en los sistemas biológicos y en los dispositivos moleculares.
- La estructura del macrociclo de la porfirina influye en la coordinación y la reactividad de los iones metálicos.
- La comprensión de la ligadura axial es clave para la función de la porfirina.
Objetivo del estudio:
- Investigar cómo el ruffling de la porfirina afecta las propiedades de ligadura axial de las porfirinas de níquel (II) tetra (II) alquilo.
- Para correlacionar las distorsiones estructurales con cambios en la afinidad de unión de ligandos.
- Explorar las implicaciones para las aplicaciones y funciones biológicas de la porfirina de níquel.
Principales métodos:
- Espectroscopia de absorción visible en los rayos UV.
- Resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia Espectroscopia Raman de resonancia
- Cristalografía de rayos X con rayos X.
- Cálculos de la mecánica molecular clásica para los cálculos de la mecánica molecular clásica.
- Análisis de descomposición estructural de coordenadas normales.
Principales resultados:
- Porphyrin ruffling disminuye la afinidad de unión para la pirrolidina y la piperidina.
- El efecto primario es una constante de unión reducida para el primer ligando axial.
- La unión de ligandos está completamente inhibida en más porfirinas no planas.
- Se requiere una energía significativa para aplanar el núcleo de porfirina para el alojamiento de iones de níquel (II).
Conclusiones:
- El ruffling de porfirina dificulta significativamente la unión del ligando axial en los complejos de níquel (II).
- La flexibilidad estructural del núcleo de la porfirina es crítica para las interacciones metal-ligando.
- Los hallazgos tienen implicaciones para el diseño de dispositivos moleculares basados en porfirina de níquel.
- Los resultados ofrecen información sobre la función de las proteínas hemo y la metil-coenzima M reductasa.
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