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Reducción gradual del nitrógeno por un complejo de uranio-potasio que produce un grupo de tetranitruro de U (VI) /U

Nadir Jori¹, Luciano Barluzzi¹, Iskander Douair²

¹Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.

Journal of the American Chemical Society

|July 16, 2021

Resumen

Este estudio reporta el primer ejemplo de la escisión del nitrógeno (N2) en nitritos por un complejo de diuranio, formando un nuevo grupo tetranuclear. Este avance ofrece nuevos conocimientos sobre los mecanismos de fijación del nitrógeno y la química de los nitruros.

Área de la Ciencia:

Química inorgánica
Química organometálica
Ciencias de los materiales

Sus antecedentes:

Se supone que la cooperatividad multimetal es crucial para la escisión del nitrógeno (N2) en nitritos (N3).
El mecanismo preciso de la escisión de N2 sigue sin estar claro debido a la ausencia de productos intermedios aislados.

Objetivo del estudio:

Investigar el mecanismo de la escisión del N2 por un complejo de diuranio.
Sintetizar y caracterizar los nuevos grupos de nitruro resultantes de la escisión del N2.
Para explorar la reactividad de las especies de nitruro resultantes.

Principales métodos:

La reducción de un complejo de diuranio [K2{[UV{OSi{OtBu) 3) ]2{μ-O}{μ-η2:η2-N2}] mediante el uso de KC8.
Aislamiento y caracterización estructural del grupo tetranitruro tetranuclear [K6{(OSi(OtBu) 3) 2UIV} 3{(OSi(OtBu) 3) 2UVI}
Estudios experimentales y computacionales para elucidar el mecanismo de reacción, incluidos los efectos de transferencia de electrones y de unión de potasio.

Principales resultados:

Síntesis exitosa de un nuevo grupo de tetranitruro tetranuclear (1) a través de la escisión de N2 por un complejo de diuranio.
La estructura del complejo 1 presenta un centro de uranio único con cuatro nitritos y un núcleo trans-NUVIN.
Los estudios mecanicistas revelaron transferencias sucesivas de un electrón y unión cooperativa de potasio que facilitan la escisión de N2 para formar un intermediario de diuranio (V) bis-nitruro (X).
Los nitritos nucleófilos reaccionan fácilmente con los protones para formar amoníaco (rendimiento del 93-97%) y con el 13CO para producir K13CN y KN13CO.

Conclusiones:

Este trabajo proporciona el primer ejemplo de escisión de N2 a nitritos mediados por un complejo de diuranio, dando como resultado un grupo tetranuclear único.
El estudio aclara el mecanismo que implica la transferencia secuencial de electrones y la asistencia de potasio en la escisión de N2.
Los grupos de nitruro sintetizados demuestran una reactividad versátil, lo que permite la formación de compuestos de amoníaco y cianuro.

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