A DFT study of a set of natural dyes for organic electronics.
J Mol Model
; 23(12): 343, 2017 Nov 17.
Article
in En
| MEDLINE
| ID: mdl-29147781
ABSTRACT
We systematically investigate, at density functional theory level, the electronic properties of a set of ten carotenoid molecules with different conjugation length. Ground state geometries were fully optimized using both B3LYP and its long-range corrected version, i.e., the CAM-B3LYP functional. The time-dependent DFT approach (TD-DFT) was also performed for the calculation of the excited states of the optimized geometries and the results were compared to the experimental ones, when available. Our findings indicate a dependence of the transition vertical energies, oscillator strengths, and transition dipole moments on the extension of conjugation, as expected. We also investigate the impact of the intra-molecular vibrations on the absorption spectrum by means of the Franck-Condon (FC) and nuclear ensemble (NE) approach to spectra simulation. Our simulations suggest that the Franck-Condon approximation may not be suitable to appropriately characterize the vibronic progression of these molecules, whereas the NE approach provides a contribution that vary from negligible to meaningful depending on which molecule and energy region is under analysis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
J Mol Model
Journal subject:
BIOLOGIA MOLECULAR
Year:
2017
Document type:
Article
Affiliation country:
Brasil