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Síntesis de la molécula de silaisocianoacetileno
Dorian S N Parker1, Antony V Wilson, Ralf I Kaiser
1Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA.
Journal of the American Chemical Society
|August 4, 2012
Resumen
Los investigadores sintetizaron por primera vez el silaisocianoacetileno (HCCNSi). Esta molécula que contiene silicio muestra una reactividad y estabilidad únicas en comparación con su análogo de carbono, el cianoacetileno.
Área de la Ciencia:
- La astroquímica es astroquímica.
- Química computacional es la química computacional.
- Química cuántica es la química cuántica.
Sus antecedentes:
- Los silaisocianuros son una clase de moléculas que contienen silicio análogas a los isocyanuros.
- La síntesis y caracterización de nuevas moléculas pequeñas que contienen silicio son cruciales para comprender el papel del silicio en los procesos químicos.
- Las relaciones isoelectrónicas entre los compuestos de carbono y silicio ofrecen información sobre la unión química y la reactividad.
Objetivo del estudio:
- Para lograr la síntesis por primera vez de la molécula de silaisocianoacetileno (HCCNSi).
- Investigar el mecanismo de reacción y la reactividad del radical de nitruro de silicio (SiN) con acetileno (C2H2).
- Para comparar la reactividad y la estabilidad del producto de los compuestos a base de silicio con sus análogos isoelectrónicos de carbono.
Principales métodos:
- Reacción en fase gaseosa del radical de nitruro de silicio (SiN) con acetileno (C2H2) en condiciones de colisión única.
- Espectrometría de masas y análisis computacional para identificar intermedios y productos de reacción.
- Cálculos teóricos para determinar las vías de reacción, las barreras de energía y las estabilidades termodinámicas.
Principales resultados:
- Se logró la síntesis de siliisocianoacetileno (HCCNSi) a través de la reacción SiN + C2H2.
- El radical SiN encuentra una barrera de entrada y se agrega a través de su átomo de nitrógeno al acetileno.
- El mecanismo de reacción y la estabilidad del producto difieren significativamente de la reacción isoelectrónica CN + C2H2, invirtiendo la estabilidad del isómero.
Conclusiones:
- La isovalencia del silicio en comparación con el carbono altera dramáticamente la reactividad, los mecanismos de reacción y la termoquímica.
- El silaisocianoacetileno (HCCNSi) y el cianoacetileno (HCCCN) exhiben propiedades químicas distintas a pesar de ser isoelectrónicos.
- Este estudio pone de relieve el comportamiento químico único del silicio en pequeñas moléculas similares a las orgánicas.
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