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Los radicales ditiazolodithiazolyl prototipo: síntesis, estructuras y propiedades de transporte
Leanne Beer1, James F Britten, Jaclyn L Brusso
1Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Journal of the American Chemical Society
|November 20, 2003
Resumen
Las nuevas rutas sintéticas producen nuevas sales de 1,2,3-dithiazolo-1,2,3-dithiazolilio. Estos materiales exhiben propiedades paramagnéticas y comportamiento semiconductor, lo que sugiere un aislante de Mott-Hubbard estado básico.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química orgánica es la química orgánica.
- Física del estado sólido Física del estado sólido
Sus antecedentes:
- Las sales de 1,2,3-dithiazol-1,2,3-dithiazolilio son una clase de compuestos orgánicos con interesantes propiedades electrónicas.
- El desarrollo de nuevas rutas sintéticas es crucial para acceder a nuevos materiales con características sintonizables.
Objetivo del estudio:
- Desarrollar nuevos métodos sintéticos para las sales de 1,2,3-dithiazolo-1,2,3-dithiazolilio.
- Caracterizar las propiedades electrónicas y estructurales de los compuestos radicales sintetizados.
- Para investigar su potencial como conductores orgánicos.
Principales métodos:
- Reacciones de condensación de doble Herz utilizando sales de 2,6-diaminopiridinium N-alquiladas y monocloruro de azufre.
- Voltametría cíclica y espectroscopia EPR para la caracterización de soluciones.
- Cristalografía de rayos X para la determinación de la estructura en estado sólido.
- Mediciones magnéticas, de conductividad y ópticas.
- Cálculos ampliados de la banda de Hückel.
Principales resultados:
- La síntesis exitosa de las nuevas sales de 1,2,3-dithiazolo-1,2,3-dithiazolylium.
- Caracterización de dos radicales prototipo (HBPMe y HBPEt) en solución.
- Las estructuras cristalinas revelan pi-stacks deslizados con estrechos contactos S- -S intermoleculares.
- Comportamiento paramagnético observado por encima de 100 K.
- Las conductividades a temperatura ambiente se encuentran en el rango de 10 (−5) -10 (−6) S cm (−1).
Conclusiones:
- Los materiales sintetizados exhiben propiedades consistentes con el estado fundamental de un aislante Mott-Hubbard.
- Se sugiere una baja energía de repulsión Coulombic (U) en el sitio, aproximadamente 1.0 eV.
- Las propiedades electrónicas están influenciadas por el empaque de cristales y las interacciones intermoleculares.
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