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Síntesis estereocontrolada y propiedades ópticas de todos los polifenilenos vinilenos (PPVs): un método para el
Hiroyuki Katayama1, Masato Nagao, Tatsuro Nishimura
1International Research Center for Elements Science (IRCELS), Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan. hiroyuki@scl.kyoto-u.ac.jp
Journal of the American Chemical Society
|March 24, 2005
Resumen
Los investigadores sintetizaron polifenilenos vinilenos (PPV) puros, todos cis, y descubrieron que se someten a fotoisomerización para convertirlos en trans-PPV. Esta propiedad permite el patronaje directo a microescala de los PPV en sustratos de cuarzo.
Área de la Ciencia:
- Química de Polímeros La Química de Polímeros es la química de los polímeros.
- Electrónica orgánica y electrónica orgánica.
- Ciencia de los materiales Ciencia de los materiales.
Sus antecedentes:
- Los polifenileno vinileno (PPV) son cruciales en la electrónica orgánica.
- El control de la pureza geométrica (isómeros cis/trans) de los PPV es esencial para ajustar sus propiedades.
- Los métodos de síntesis existentes pueden no lograr una alta pureza geométrica.
Objetivo del estudio:
- Desarrollar un método para sintetizar polifenileno vinileno (PPV) geométricamente puro, todo-cis.
- Para investigar el comportamiento de fotoisomerización de estos PPVs todo-cis.
- Demostrar una nueva aplicación de esta fotoisomerización para el patroneado de materiales.
Principales métodos:
- Policondensación tipo Suzuki-Miyaura utilizando ácido diborónico específico y monómeros de dibromovinilbenceno.
- Hidrosilación doble selectiva catalizada por rutenio (Z) para la síntesis de precursores.
- Bromodesilación mediante el uso de N-bromosuccinimida.
- Estudios de fotoisomerización en disolución y estado sólido.
- Patrones a microescala en sustratos de cuarzo.
Principales resultados:
- Síntesis exitosa de PPVs geométricamente puros, todo-cis.
- Observación de la fotoisomerización unidireccional de todas las cis a las trans-PPV.
- Demostración del patrón controlado a microescala de los PPV a través de la fotoisomerización.
Conclusiones:
- Los PPVs geométricamente puros pueden sintetizarse utilizando la policondensación Suzuki-Miyaura descrita.
- La fotoisomerización de PPVs all-cis a PPVs trans es un fenómeno robusto aplicable en varios estados.
- Esta fotoisomerización ofrece una nueva ruta para el patronaje directo de alta resolución de materiales PPV.
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