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Time-dependent density functional investigation on electronic spectra of 4′-N-dimethylamino-3-hydroxyflavone
- Source :
-
Journal of Molecular Structure: THEOCHEM . Oct2005, Vol. 731 Issue 1-3, p219-224. 6p. - Publication Year :
- 2005
-
Abstract
- Abstract: The lower singlet excited states for 4′-N-dimethylamino-3-hydroxyflavone (DMA3HF) have been investigated. Theoretical calculations have been performed by using time-dependent density functional theory. The B3LYP and MPW1PW91 functionals with 6-31G(d,p) basis set have been used to compute transition energies. Ground-state geometries are optimized by using density functional theory with both B3LYP and MPW1PW91 functionals combined with 6-31G(d,p) basis set. The first excited state geometries are optimized by using configuration interaction all single-excitations methods with 6-31G(d,p). Vertical absorption energy and excited state electronic dipole moments calculations show that the singlet excited states S1 of the normal of DMA3HF has the character of a large charge separation and effective charge transfer. Calculated emission energies for both the normal and tautomer show a large Stokes shift between the absorption and fluorescence maxima. The present calculations suggest that DMA3HF appears dual fluorescence in gas phase. Our results obtained explain the strong ‘dual-fluorescence’ feature that involves the excited-state intramolecular proton transfer and charge transfer of DMA3HF. [Copyright &y& Elsevier]
Details
- Language :
- English
- ISSN :
- 01661280
- Volume :
- 731
- Issue :
- 1-3
- Database :
- Academic Search Index
- Journal :
- Journal of Molecular Structure: THEOCHEM
- Publication Type :
- Academic Journal
- Accession number :
- 18729168
- Full Text :
- https://doi.org/10.1016/j.theochem.2005.05.032