Simulating the full spin manifold of triplet-pair states in a series of covalently linked TIPS-pentacenes.
J Comput Chem
; 2024 Aug 14.
Article
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| MEDLINE
| ID: mdl-39139132
ABSTRACT
Combined density functional theory and multireference configuration interaction methods have been used to elucidate singlet fission (SF) pathways and mechanisms in three regioisomers of side-on linked pentacene dimers. In addition to the optically bright singlets (S 1 $$ {}_1 $$ and S 2 $$ {}_2 $$ ) and singly excited triplets (T 1 $$ {}_1 $$ and T 2 $$ {}_2 $$ ), the full spin manifold of multiexcitonic triplet-pair states ( 1 $$ {}^1 $$ ME, 3 $$ {}^3 $$ ME, 5 $$ {}^5 $$ ME) has been considered. In the ortho- and para-regioisomers, the 1 $$ {}^1 $$ ME and S 1 $$ {}_1 $$ potentials intersect upon geometry relaxation of the S 1 $$ {}_1 $$ excitation. In the meta-regioisomer, the crossing occurs upon delocalization of the optically bright excitation. The energetic accessibility of these conical intersections and the absence of low-lying charge-transfer states suggests a direct SF mechanism, assisted by charge-resonance effects in the 1 $$ {}^1 $$ ME state. While the 5 $$ {}^5 $$ ME state does not appear to play a role in the SF mechanism of the ortho- and para-regioisomers, its participation in the disentanglement of the triplet pair is conceivable in the meta-regioisomer.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
J Comput Chem
/
J. comput. chem
/
Journal of computational chemistry
Asunto de la revista:
QUIMICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Estados Unidos