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Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
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Aislamiento de germanio acíclico transitorio (I) y radicales estabilizados por alquil (Amino) carbenos
Mujahuddin M Siddiqui1, Samir Kumar Sarkar1, Soumen Sinhababu1
1Institut für Anorganische Chemie , Universität Göttingen , Tammannstrasse 4 , 37077 , Göttingen , Germany.
Journal of the American Chemical Society
|January 12, 2019
Resumen
Los investigadores sintetizaron y caracterizaron nuevos radicales de germanio neutro acíclico, superando los desafíos sintéticos anteriores. Estos radicales estables de germanio representan un avance significativo en la química de los elementos del grupo principal.
Área de la Ciencia:
- Química organometálica
- Química de los elementos del grupo principal
- Estabilización radical
Sus antecedentes:
- Los radicales del grupo principal, particularmente los de silicio y germanio, son difíciles de aislar debido a su alta susceptibilidad a la dimerización.
- Si bien los carbenos N-heterocíclicos (NHC) y los alquil-aminocarbenos cíclicos (cAAC) han demostrado tener éxito en la estabilización de los radicales del grupo principal, los radicales de germanio siguen siendo escurridizos.
- Los esfuerzos sintéticos anteriores se han visto obstaculizados por la reactividad inherente y la naturaleza transitoria de estas especies.
Objetivo del estudio:
- Informar sobre la síntesis y el aislamiento exitosos de nuevos radicales de germanio neutro acíclico.
- Caracterizar estos radicales de germanio utilizando una combinación de métodos experimentales y teóricos.
- Investigar las propiedades estructurales y de unión de los compuestos de germanio sintetizados.
Principales métodos:
- Síntesis de radicales de germanio mediante la reducción de los precursores de [ArSiR3]NGeCl3 con KC8 en presencia de un alquilo (amino) carbeno cíclico (cAAC).
- Técnicas de caracterización que incluyen análisis estructural de rayos X de un solo cristal, voltametría cíclica y espectroscopia de resonancia paramagnética de electrones (EPR).
- Investigaciones computacionales que utilizan métodos teóricos para analizar la estructura y el enlace.
Principales resultados:
- Síntesis exitosa de dos radicales distintos de germanio neutral acíclico: Cy-cAAC: GeN ((SiMe3) Dip (1) y Me-cAAC: GeN ((SiPh3) Mes (2).
- Caracterización exhaustiva que confirma la existencia estable de estas especies de radicales de germanio.
- Conocimientos estructurales y electrónicos detallados obtenidos por difracción de rayos X, electroquímica, EPR y cálculos teóricos.
Conclusiones:
- El desarrollo de una vía sintética viable permite el aislamiento de radicales de germanio neutro acíclicos anteriormente inaccesibles.
- La estabilización lograda a través del ligando cAAC es crucial para prevenir la dimerización y aislar estas especies reactivas.
- Este trabajo avanza significativamente en el campo de la química de los radicales de grupo principal, abriendo nuevas vías para los compuestos a base de germanio.
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