Signatures of intramolecular vibrational and vibronic Q[Formula: see text]-Q[Formula: see text] coupling effects in absorption and CD spectra of chlorophyll dimers.
Photosynth Res
; 156(1): 19-37, 2023 Apr.
Article
em En
| MEDLINE
| ID: mdl-36040654
ABSTRACT
An electron-vibrational coupling model that includes the vibronic (non-adiabatic) coupling between the Q[Formula see text] and Q[Formula see text] transitions of chlorophyll (Chl), created by Reimers and coworkers (Scientific Rep. 3, 2761, 2013) is extended here to chlorophyll dimers with interchlorophyll excitonic coupling. The model is applied to a Chl a dimer of the water-soluble chlorophyll binding protein (WSCP). As for isolated chlorophyll, the vibronic coupling is found to have a strong influence on the high-frequency vibrational sideband in the absorption spectrum, giving rise to a band splitting. In contrast, in the CD spectrum the interplay of vibronic coupling and static disorder leads to a strong suppression of the vibrational sideband in excellent agreement with the experimental data. The conservative nature of the CD spectrum in the low-energy region is found to be caused by a delicate balance of the intermonomer excitonic coupling between the purely electronic Q[Formula see text] transition and the Q[Formula see text] transition involving intramolecular vibrational excitations on one hand and the coupling to higher-energy electronic transitions on the other hand.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Clorofila
Idioma:
En
Revista:
Photosynth Res
Assunto da revista:
METABOLISMO
Ano de publicação:
2023
Tipo de documento:
Article
País de afiliação:
Áustria