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Resonancia de las fases de onda de densidad de enlace de valencia y de carga sigma en un radical fenalenilo

Pradip Bag¹, Mikhail E Itkis, Sushanta K Pal

¹Department of Chemistry, University of California, Riverside, California 92521-0403, USA.

Journal of the American Chemical Society

|February 9, 2010

Resumen

Los investigadores desarrollaron un nuevo conductor de radicales fenalenilo benzanulados. Este material exhibe un comportamiento único en estado sólido, con estructuras de onda de cadena pi y densidad de carga que influyen en la conductividad y el magnetismo.

Área de la Ciencia:

Ciencia de los materiales Ciencia de los materiales.
Física del estado sólido Física del estado sólido
Electrónica orgánica y electrónica orgánica.

Sus antecedentes:

Los radicales fenalenilo son conocidos por sus interesantes propiedades electrónicas y magnéticas.
La comprensión de las interacciones intermoleculares es crucial para el diseño de nuevos materiales conductores.

Objetivo del estudio:

Para sintetizar y caracterizar el primer benzanulado fenalenilo conductor de radicales neutros.
Para investigar el comportamiento sin precedentes del estado sólido y las fases que compiten en este nuevo material.

Principales métodos:

Difracción de rayos X de un solo cristal para determinar las estructuras cristalinas a varias temperaturas.
Mediciones de conductividad eléctrica.
Mediciones de la susceptibilidad magnética.

Principales resultados:

El compuesto exhibe dos interacciones intermoleculares dominantes: el apilamiento de cadenas pi y la superposición entre cadenas C4-C4.
La estructura de la temperatura ambiente está descrita por el modelo de enlace de valencia resonante (RVB).
Surge una fase de onda de densidad de carga sigma (sigma-CDW) competitiva, particularmente alrededor de 150 K, que afecta la conductividad y el magnetismo.

Conclusiones:

El conductor del radical fenalenil benzanulado muestra una compleja interacción entre las fases RVB y sigma-CDW.
Esta competencia conduce a propiedades únicas y sintonizables del estado sólido relevantes para la electrónica orgánica.

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