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Un congénero de silicio estable de biciclo altamente tensado [3.2.0]hepta-1,3,6-trieno
Yoshihiro Kon1, Jun Ogasawara, Kenkichi Sakamoto
1Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Journal of the American Chemical Society
|August 2, 2003
Resumen
Los investigadores sintetizaron un compuesto bicíclico altamente tenso que contiene silicio con una estructura de doble enlace única. A pesar de la tensión significativa, los sustitutos voluminosos proporcionan una notable estabilidad, lo que le permite persistir en el aire durante meses.
Área de la Ciencia:
- Química del organosilicio Química del organosilicio
- Química orgánica sintética y orgánica.
- Teoría de la deformación Teoría de la deformación.
Sus antecedentes:
- Los sistemas de bicicletas fundidas ofrecen propiedades estructurales y electrónicas únicas.
- Las moléculas orgánicas altamente tensas desafían los paradigmas convencionales de estabilidad.
- La incorporación del silicio en marcos orgánicos puede conducir a una nueva reactividad y estabilidad.
Objetivo del estudio:
- Para sintetizar y caracterizar un nuevo compuesto bicíclico fundido que contiene silicio con un doble enlace de cabeza de puente tensa.
- Investigar las implicaciones estructurales y de estabilidad de la alta tensión estérica en compuestos orgánicos de silicio.
- Explorar la relación entre el volumen estérico y la estabilidad molecular en sistemas tensos.
Principales métodos:
- Síntesis cuantitativa a través de la reacción de un silatriafulveno con di-tert-butilociclopropenona.
- Análisis cristalográfico de rayos X para determinar la estructura molecular precisa y los ángulos de enlace.
- Modelado computacional (MP2/B3LYP) para calcular la energía de deformación.
Principales resultados:
- Se ha logrado la síntesis de 2,3,6,7-tetra-tert-butyl-4-(tert-butyldimethylsilyl)-5-(tert-butyldimethylsiloxy)-5-silabicyclo[3.2.0]hepta-1,3,6-trieno (2).
- El análisis de rayos X confirmó un silole fundido y un sistema de anillos de silaciclobuteno con una deformación significativa del doble enlace (suma del ángulo de enlace de carbono de la cabeza de puente de 333 °).
- Energía de deformación calculada (30,2 kcal/mol) comparable a su análogo carbocíclico, lo que indica una alta deformación inherente.
Conclusiones:
- El compuesto sintetizado exhibe una estructura de silano bicíclico altamente tensa.
- A pesar de la tensión extrema, la molécula demuestra una notable estabilidad al aire debido a la protección estérica de los voluminosos grupos tert-butilo y tert-butildimetilesil.
- Este estudio pone de relieve el potencial para la estabilización de compuestos orgánicos de silicio de alta tensión a través de la colocación estratégica de sustitutos.
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