2,7‐Substituted N ‐Carbazole Donors on Tris (2,4,6‐trichlorophenyl) methyl Radicals with High Quantum Yield

Abstract: Doublet spin properties of organic open‐shell luminophores evade the formation of dark triplet states, thus making radicals favorable emitters for next generation organic light‐emitting diodes. However, their poor photostability and mediocre photoluminescence quantum yields (PLQYs) limit their application. In this work, two series of trityl radicals functionalized with one, two, and three 2,7‐disubstituted carbazole units are presented. The authors either attach nitriles or bromines as electron‐withdrawing 2,7‐substituents. The resulting radical emitters exhibit outstanding optical properties. The electron‐withdrawing properties of the substituents lead to a blue‐shift of the emission, indicating a starting point for future emission engineering into the green spectrum. Due to the 2,7‐substitution of the carbazole moiety, the radical emitters are sterically more hindered than the commonly used 3,6‐substituted carbazoles. This steric hindrance reduces non‐radiative decay pathways in the molecules, enhancing photostability and pushing PLQYs up to 87%. Quantum mechanical calculations elucidate the influence of the electron withdrawing substituents on the optical performance of the open‐shell molecules. The authors also show that intensity borrowing from higher lying locally excited states contributes to these exceptionally high PLQYs.

Standort
Deutsche Nationalbibliothek Frankfurt am Main
Umfang
Online-Ressource
Sprache
Englisch

Erschienen in
2,7‐Substituted N ‐Carbazole Donors on Tris (2,4,6‐trichlorophenyl) methyl Radicals with High Quantum Yield ; day:18 ; month:02 ; year:2022 ; extent:7
Advanced optical materials ; (18.02.2022) (gesamt 7)

Urheber
Chen, Lisa
Arnold, Mona
Kittel, Yonca
Blinder, Rémi
Jelezko, Fedor
Kuehne, Alexander J. C.

DOI
10.1002/adom.202102101
URN
urn:nbn:de:101:1-2022021914081004659591
Rechteinformation
Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
Letzte Aktualisierung
15.08.2025, 07:21 MESZ

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Beteiligte

  • Chen, Lisa
  • Arnold, Mona
  • Kittel, Yonca
  • Blinder, Rémi
  • Jelezko, Fedor
  • Kuehne, Alexander J. C.

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