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Fase isotrópica de reentrada entre las mesofasas lamelar y columnar
Urszula Pietrasik1, Jadwiga Szydłowska, Adam Krówczyński
1Chemistry Department, Warsaw University, Laboratory of Dielectrics and Magnetics, Al. Zwirki i Wigury 101, 02-089 Warsaw, Poland.
Journal of the American Chemical Society
|July 26, 2002
Resumen
Los complejos de níquel (II) sintetizados con enlaces de hidrógeno intramoleculares exhiben propiedades únicas de cristal líquido. Se observó por primera vez una fase de reentrada isotrópica entre las fases columnar y lamelar.
Área de la Ciencia:
- Coordinación Química de la Coordinación
- Ciencia de los materiales Ciencia de los materiales.
- Cristales líquidos de cristales líquidos
Sus antecedentes:
- Se sintetizaron complejos tetradentales de cis-enaminoketona Ni (II). complejos fueron sintetizados.
- Se introdujeron enlaces de hidrógeno intramoleculares para modificar la estructura y las propiedades moleculares.
Objetivo del estudio:
- Investigar la influencia de la forma molecular y la unión de hidrógeno en el comportamiento cristalino líquido de los complejos de Ni (II).
- Explorar nuevas secuencias de fase en compuestos sintetizados.
Principales métodos:
- Síntesis de los complejos tetradentales de cis-enaminoketona Ni (II).
- Caracterización de la estructura molecular y el comportamiento de fase.
Principales resultados:
- Los complejos con enlaces de hidrógeno intramoleculares y cadenas terminales alkoxi mostraron una secuencia de fase poco común: Iso-D(h) -Iso(re) -SmA.
- Se observó por primera vez la fase de reingreso isotrópico (Iso(re), que separa las fases columnar (D) y lamelar (SmA).
Conclusiones:
- Los enlaces de hidrógeno intramoleculares tienen un impacto significativo en las propiedades mesogénicas de los complejos de Ni (II).
- El descubrimiento de la fase de reentrada isotrópica entre las fases columnar y lamelar ofrece nuevos conocimientos sobre las transiciones de fase de los cristales líquidos.
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