High stability and luminescence efficiency in donor-acceptor neutral radicals not following the Aufbau principle.
Nat Mater
; 18(9): 977-984, 2019 Sep.
Article
em En
| MEDLINE
| ID: mdl-31332338
ABSTRACT
With their unusual electronic structures, organic radical molecules display luminescence properties potentially relevant to lighting applications; yet, their luminescence quantum yield and stability lag behind those of other organic emitters. Here, we designed donor-acceptor neutral radicals based on an electron-poor perchlorotriphenylmethyl or tris(2,4,6-trichlorophenyl)methyl radical moiety combined with different electron-rich groups. Experimental and quantum-chemical studies demonstrate that the molecules do not follow the Aufbau principle the singly occupied molecular orbital is found to lie below the highest (doubly) occupied molecular orbital. These donor-acceptor radicals have a strong emission yield (up to 54%) and high photostability, with estimated half-lives reaching up to several months under pulsed ultraviolet laser irradiation. Organic light-emitting diodes based on such a radical emitter show deep-red/near-infrared emission with a maximal external quantum efficiency of 5.3%. Our results provide a simple molecular-design strategy for stable, highly luminescent radicals with non-Aufbau electronic structures.
Texto completo:
1
Bases de dados:
MEDLINE
Idioma:
En
Revista:
Nat Mater
Assunto da revista:
CIENCIA
/
QUIMICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
China