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From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Published on: March 24, 2018

Cambio gradual entre regímenes de tunelado coherentes e incoherentes inducidos por sustitutos de haluros polarizables

Xiaoping Chen^1,2, Ira Volkova², Yulong Wang²

¹College of Chemistry, Chemical Engineering and Environment, Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, Minnan Normal University, Zhangzhou 363000, China.

Journal of the American Chemical Society

|August 8, 2024

Resumen

Los investigadores demostraron un cambio gradual del transporte de carga coherente a incoherente en las uniones moleculares al aumentar la polarizabilidad del sustituto halogenado. Esta transición mejoró el rendimiento del diodo molecular, lo que sugiere un nuevo método para mejorar los dispositivos electrónicos moleculares.

Área de la Ciencia:

La electrónica molecular
Física de la materia condensada
Ciencias de los materiales

Sus antecedentes:

Los mecanismos de transporte de carga en las uniones moleculares son cruciales para el rendimiento del dispositivo.
Los métodos anteriores para inducir el túnel incoherente involucraron grupos redox o aumento de la longitud molecular.
Comprender el papel de las propiedades sustitutivas en el transporte de carga es clave.

Objetivo del estudio:

Investigar el efecto de la polarizabilidad del sustituyente halogenado en los mecanismos de transporte de carga en las uniones moleculares.
Explorar un nuevo enfoque para ajustar el transporte de carga desde el túnel coherente al incoherente.
Para correlacionar los cambios en el mecanismo de túnel con el rendimiento del diodo molecular.

Principales métodos:

Monocapas alifáticas sintetizadas con terminación fenílica con sustituyentes halogenados variables (F, Cl, Br, I) y números (n=0, 1, 2, 3, 5).
Se fabricaron y caracterizaron las uniones moleculares utilizando estas monocapas.
Se analizaron las propiedades de transporte de carga, incluida la energía de activación, para determinar los mecanismos de túnel.

Principales resultados:

Se ha demostrado una transición gradual de tunelado coherente a incoherente con un aumento de la polarizabilidad de halogenuros.
Se observó un aumento significativo de la energía de activación de 23 meV (coherente) a 257 meV (incoherente).
Mostró una mejora en el rendimiento del diodo molecular correlacionado con el aumento de la tasa de túnel incoherente.

Conclusiones:

La polarizabilidad del sustituyente molecular es un factor crítico en el control de los mecanismos de transporte de carga.
El aumento de la polarizabilidad ofrece una vía viable para ajustar el túnel de regímenes coherentes a incoherentes.
Esta estrategia proporciona una vía para mejorar la función electrónica de los dispositivos moleculares.

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