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Difuncionalización de alqueno catalizado por níquel como método para la polimerización
Julia N Katzbaer1, Vincent M Torres1, Elizabeth Elacqua1
1Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Journal of the American Chemical Society
|June 21, 2023
Resumen
Este estudio introduce una nueva difuncionalización de alqueno catalizado por níquel para la síntesis de polímeros, creando poli[arileno-α-arilo]etileno únicos con intervalos regulares de grupos arilo y alta estabilidad térmica.
Área de la Ciencia:
- Química de los polímeros
- Síntesis orgánica
- Ciencias de los materiales
Sus antecedentes:
- La difuncionalización de alceno es una herramienta sintética clave para crear moléculas complejas.
- Su aplicación en la síntesis de polímeros, en particular para polímeros estereodefinidos, permaneció inexplorada.
- El desarrollo de nuevos métodos de polimerización es crucial para los materiales avanzados.
Objetivo del estudio:
- Informar el primer ejemplo de difuncionalización de alceno catalizado por níquel para la síntesis de polímeros.
- Investigar la regioselectividad y las características de los polímeros resultantes.
- Explorar el potencial de este método para la creación de nuevos polietileno-alfaetileno.
Principales métodos:
- Difuncionalización catalizada por níquel de alquenos utilizando ésteres arilborónicos y bromuros de arilo.
- La polimerización regioselectiva con adición específica a través del alqueno.
- Fraccionamiento para aislar polímeros de las especies oligoméricas.
- Análisis térmico (TGA, DSC) para determinar las propiedades del polímero.
Principales resultados:
- Síntesis exitosa de poli[arileno-alfa-arilo]etileno a través de una nueva polimerización de difuncionalización catalizada por Ni.
- Adición regioselectiva de bromuro de arilo al carbono terminal y de éster arilborónico al carbono bencílico interno.
- Se obtienen polímeros con pesos moleculares comprendidos entre 30 y 175 kDa.
- Los polímeros exhiben una alta estabilidad térmica (hasta ~ 399 °C) y una temperatura de transición de vidrio (Tg) de 90 °C.
Conclusiones:
- Este trabajo establece una nueva ruta para la síntesis de poli[arileno-alfa-aril]etileno a través de la difuncionalización de alquenos.
- Los polímeros resultantes poseen propiedades térmicas deseables comparables a los polímeros establecidos como el poliestireno.
- Este método abre caminos para la ingeniería de polímeros avanzados con propiedades a medida.
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