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Aislamiento de dos derivados del fullereno C58 de anillo de siete miembros: C58F17CF3 y C58F1818
Pavel A Troshin1, Anthony G Avent, Adam D Darwish
1Institute of Problems of Chemical Physics of Russian Academy of Sciences, Chernogolovka 142432, Russia.
Science (New York, N.Y.)
|July 9, 2005
Resumen
Los investigadores sintetizaron los nuevos derivados del fullereno C58, C58F18 y C58F17CF3, mediante la fluoración del C60. Este avance supera los problemas de deformación en los fullerenos más pequeños, revelando nuevas estructuras de jaula de carbono.
Área de la Ciencia:
- Química de los fullerenos.
- Síntesis orgánica La síntesis orgánica.
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- Los fullerenos, particularmente las estructuras de jaula más pequeñas, son difíciles de sintetizar debido a la tensión inherente.
- Los intentos anteriores de crear cuasi-fullerenos más pequeños se han visto obstaculizados por la estabilidad y las dificultades sintéticas.
Objetivo del estudio:
- Para sintetizar y caracterizar derivados estables y más pequeños de fullereno de C60.
- Investigar el mecanismo de pérdida de carbono durante la fluoración del C60.
- Comprender cómo la adición de flúor afecta la estructura y la estabilidad de la jaula del fullereno.
Principales métodos:
- La fluoración a alta temperatura del C60 a 550°C.
- Caracterización mediante espectrometría de masas (MS) y espectroscopia de resonancia magnética nuclear (19F NMR) con fluoruro.
- Análisis de los derivados de fullereno resultantes (C58F18 y C58F17CF3).
Principales resultados:
- Se sintetizaron con éxito cantidades miligráficas de dos derivados estables del fullereno C58, C58F18 y C58F17CF3.
- El análisis estructural indicó la presencia de un anillo heptagonal dentro del marco de los fullerenos.
- La adición de flúor indujo un cambio de hibridación de sp2 a sp3 en algunos carbonos pentagonales, aliviando la tensión.
Conclusiones:
- El estudio presenta un método viable para producir derivados de fullereno más pequeños y estables.
- Las modificaciones estructurales observadas, incluidos los anillos heptagonales y la hibridación sp3, explican la estabilización de estos cuasi-fullerenos.
- Un mecanismo propuesto para la pérdida de carbono implica la adición secuencial de flúor y la eliminación de carbenos.
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