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Transición de cristales bidimensionales de radialeno a cumuleno en Ag ((111) a través de la retroadición [2 + 1]

Jian-Wei Liu¹, Ying Wang¹, Li-Xia Kang¹

¹Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, State Key Laboratory of Chemical Engineering, School of Chemistry and Molecular Engineering, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, China.

Journal of the American Chemical Society

|June 8, 2023

Resumen

Los investigadores lograron una transición de cristal 2D altamente selectiva del radialeno al cumuleno en las superficies. Este avance de la ingeniería del cristal visualiza el complejo proceso dinámico, permitiendo la síntesis de nuevos materiales.

Área de la Ciencia:

Ciencias de la superficie y química de los materiales
Química supramolecular y ingeniería de cristales

Sus antecedentes:

Las transiciones bidimensionales (2D) de cristal a cristal son cruciales para sintetizar diversos materiales a partir de un solo precursor.
El control de estas transiciones con alta quimioselectividad y estereoselectividad en superficies bajo vacío ultraalto (UHV) sigue siendo un desafío debido a su dinámica compleja.

Objetivo del estudio:

Para lograr una transición cristalina 2D altamente quimioselectiva de radialeno a cumuleno en una superficie.
Visualizar y comprender el proceso dinámico y el mecanismo de crecimiento de esta transición con estereoselectividad.
Para proporcionar información sobre la ingeniería de cristales 2D controlables.

Principales métodos:

Se utilizó microscopía de túnel de barrido (STM) y microscopía de fuerza atómica sin contacto (nc-AFM) para visualizar el proceso de transición.
Se emplean técnicas de recocido progresivo para controlar las vías de reacción.
Condujo cálculos de la teoría funcional de la densidad (DFT) para dilucidar los mecanismos de reacción.

Principales resultados:

Se ha demostrado una transición 2D altamente quimioselectiva de radialeno a cumuleno en Ag{11} a través de la retro- [2 + 1] cicloadición.
Se observa la cicloadición secuencial [1 + 1 + 1] y el reconocimiento enantioselectivo que forman cristales de triaza [2] radialeno 2D a bajas temperaturas.
Se mostró que las temperaturas más altas indujeron la transformación a trans-diaza[3]cumulenes, ensamblándose en cristales de cumuleno 2D a través de la coordinación N-Ag-N y la unión C-H··Cl.

Conclusiones:

La retro- [2 + 1] cicloadición procede a través de la apertura del anillo, la desclorinación / pasivación de hidrógeno y la desizociación.
El estudio proporciona una visualización directa del mecanismo de crecimiento epitaxial paso a paso en las transiciones cristalinas 2D.
Los hallazgos ofrecen implicaciones significativas para la ingeniería controlable de materiales de cristal 2D.

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