Balanced Energy Gaps as a Key Design Rule for Solution-Phase Organic Room Temperature Phosphorescence.
Chemistry
; 29(42): e202301369, 2023 Jul 26.
Article
em En
| MEDLINE
| ID: mdl-37154211
ABSTRACT
Metal-free organic emitters that display solution-phase room temperature phosphorescence (sRTP) remain exceedingly rare. Here, we investigate the structural and photophysical properties that support sRTP by comparing a recently reported sRTP compound (BTaz-Th-PXZ) to two novel analogous materials, replacing the donor group by either acridine or phenothiazine. The emissive triplet excited state remains fixed in all three cases, while the emissive charge-transfer singlet states (and the calculated paired charge-transfer T2 state) vary with the donor unit. While all three materials show dominant RTP in film, in solution different singlet-triplet and triplet-triplet energy gaps give rise to triplet-triplet annihilation followed by weak sRTP for the new compounds, compared to dominant sRTP throughout for the original PXZ material. Engineering both the sRTP state and higher charge-transfer states therefore emerges as a crucial element in designing emitters capable of sRTP.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article