Photophysical Study of 1,5 – Diaminoanthraquinone in Different Solvents and at Various pH
The absorption and fluorescence spectral properties 1,5-diaminoanthraquinone (DAAQ) have been investigated in a series of organic solvents of different polarity and in aqueous solutions with Ho / pH /H– in the range -10 to 17. The Stokes shifts of DAAQ are correlated with various solvent polarity sc...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2007-01-01
|
| Series: | E-Journal of Chemistry |
| Online Access: | http://dx.doi.org/10.1155/2007/282979 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The absorption and fluorescence spectral properties 1,5-diaminoanthraquinone (DAAQ) have been investigated in a series of organic solvents of different polarity and in aqueous solutions with Ho / pH /H– in the range -10 to 17. The Stokes shifts of DAAQ are correlated with various solvent polarity scales. The better correlation of Stokes shifts of DAAQ with ET(30) indicates the predominance of hydrogen bonding interactions over dipolar interactions. The study also reveals that the fluorescence of DAAQ dication is red shifted on protonation. The abnormal fluorescence of DAAQ is found to be due to large solvent relaxation in polar medium. The acidity constants for various prototropic reactions in So and S1 states are determined and discussed. |
|---|---|
| ISSN: | 0973-4945 2090-9810 |