Key of Suppressed Triplet Nonradiative Transition-Dependent Chemical Backbone for Spatial Self-Tunable Afterglow.
JACS Au
; 1(7): 945-954, 2021 Jul 26.
Article
en En
| MEDLINE
| ID: mdl-34467341
Highly efficient persistent (lifetime > 0.1 s) room-temperature phosphorescence (pRTP) chromophores are important for futuristic high-resolution afterglow imaging for state-of-the-art security, analytical, and bioimaging applications. Suppression of the radiationless transition from the lowest triplet excited state (T1) of the chromophores is a critical factor to access the high RTP yield and RTP lifetime for desirable pRTP. Logical explanations for factor suppression based on chemical structures have not been reported. Here we clarify a strategy to reduce the radiationless transition from T1 based on chemical backbones and yield a simultaneous high RTP yield and high RTP lifetime. Yellow phosphorescence chromophores that contain a coronene backbone were synthesized and compared with yellow phosphorescent naphthalene. One of the designed coronene derivatives reached a RTP yield of 35%, which is the best value for chromophores with a RTP lifetime of 2 s. The optically measured rate constant of a radiationless transition from T1 was correlated precisely with a multiplication of vibrational spin-orbit coupling (SOC) at a T1 geometry and with the Franck-Condon chromophore factor. The agreement between the experimental and theoretical results confirmed that the extended two-dimensional fused structure in the coronene backbone contributes to a decrease in vibrational SOC and Franck-Condon factor between T1 and the ground state to decrease the radiationless transition. A resolution-tunable afterglow that depends on excitation intensity for anticounterfeit technology was demonstrated, and the resultant chromophores with a high RTP yield and high RTP lifetime were ideal for largely changing the resolution using weak excitation light.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
JACS Au
Año:
2021
Tipo del documento:
Article
País de afiliación:
Japón
Pais de publicación:
Estados Unidos