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Complejos de zinc tetraédricos con propiedades cristalinas líquidas y luminiscentes: interacción entre formas
Emma Cavero1, Santiago Uriel, Pilar Romero
1Departamento de Química OrgAnica y Química Física, Area de Química OrgAnica, Facultad de Ciencias-Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain.
Journal of the American Chemical Society
|August 24, 2007
Resumen
Los nuevos complejos de zinc exhiben comportamiento de cristal líquido a temperatura ambiente y luminiscencia. Sus estructuras no planas únicas permiten la autoorganización en columnas y la emisión de luz, ofreciendo nuevas posibilidades para materiales avanzados.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química supramolecular de las moléculas.
- Coordinación Química de la Coordinación
Sus antecedentes:
- Los cristales líquidos convencionales suelen poseer formas moleculares en forma de varilla o disco.
- Los metallomesógenos combinan elementos metálicos con propiedades cristalinas líquidas.
- Los materiales luminiscentes son cruciales para las aplicaciones ópticas y electrónicas.
Objetivo del estudio:
- Para sintetizar nuevos metalomesógenos luminiscentes con estructuras moleculares no convencionales.
- Para investigar el comportamiento cristalino líquido y el autoensamblaje de nuevos complejos de zinc.
- Explorar la relación entre la arquitectura molecular, la formación de la mesofase y la luminiscencia.
Principales métodos:
- Preparación y caracterización de complejos de zinc con pirazol y ligandos de bis ((pyrazolyl) metano.
- Difracción de rayos X monocristalino para el análisis estructural.
- Difracción de rayos X de ángulo pequeño (XRD) para la investigación de la mesofase.
- Espectroscopia de fotoluminiscencia para estudiar las propiedades ópticas.
Principales resultados:
- Se ha logrado un comportamiento cristalino líquido a temperatura ambiente (mesofasas lamelares y columnares) en nuevos complejos de zinc.
- Metalomesógenos sintetizados con formas moleculares no convencionales y no planas debido a centros de zinc tetraédricos y espaciadores de metileno.
- Luminiscencia observada en la región cercana al azul UV con grandes desplazamientos de Stokes.
- Modelos supramoleculares propuestos para la organización molecular en mesofasas basados en datos XRD.
Conclusiones:
- Los ligandos de pirazol diseñados y los centros de zinc tetraédricos conducen a formas moleculares únicas y arreglos columnares supramoleculares a temperatura ambiente.
- Estos metalomesógenos exhiben una combinación de autoorganización columnar y luminiscencia con débiles interacciones intermoleculares.
- La interacción entre la forma molecular y el orden supramolecular da como resultado materiales con propiedades duales, adecuados para aplicaciones avanzadas.
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