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Isomerización ascendente asistida por átomo de hidrógeno de N-metilformamida en la oscuridad

Shih-Yi Tsai¹, Karolina Anna Haupa^1,2, Yuan-Pern Lee^1,3

¹Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan.

Journal of the American Chemical Society

|June 30, 2022

Resumen

Las moléculas prebióticas como la N-metilformamida (NMF) pueden isomerizar en la oscuridad a través del túnel del átomo H, formando cis-NMF de mayor energía. Este proceso, observado en el parahidrógeno sólido, revela una nueva vía para la química interestelar.

Área de la Ciencia:

Astroquímica
La cinética química
El túnel cuántico

Sus antecedentes:

La N-metilformamida (NMF) es la amida interestelar más pequeña, que existe como isómeros cis y trans.
Comprender las vías de isomerización es crucial para identificar moléculas prebióticas en el espacio.

Objetivo del estudio:

Para investigar la isomerización del NMF en el medio interestelar.
Explorar el papel de las reacciones del átomo H en la formación y transformación de moléculas prebióticas.

Principales métodos:

Reacciones de átomos de H con trans-NMF en parahidrógeno sólido a 3,3 K.
Espectroscopia infrarroja para la identificación de productos intermedios y productos de reacción.

Principales resultados:

El isómero cis-NMF de mayor energía aumentó en la oscuridad, lo que indica una isomerización independiente de la luz.
Los radicales intermedios identificados son: trans-C ((O) NH ((CH3) y trans-HC ((O) NH ((CH2).
La adición y la abstracción de H condujeron a la formación de CH3NCO, HNCO y CH2NH.

Conclusiones:

El túnel de átomos de H permite la isomerización de NMF en ausencia de luz.
Las vías de fragmentación vinculan el NMF con el HCNO y el CH2NH.
Las reacciones endotérmicas son facilitadas por el acoplamiento H + H → H2.

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