| Affiliation: | 1. Department of Chemistry , Florida Atlantic University , 500 N.W. 20th Street, P. O. Box 3091, Boca Raton , FL , 33431-0991 , U.S.A.;2. Department of Chemistry , Florida Atlantic University , 500 N.W. 20th Street, P. O. Box 3091, Boca Raton , FL , 33431-0991 , U.S.A.;3. Department of Chemistry , Faculty of Science, Ain Shams University , Abbassia , Cairo , Egypt;4. Institut de Topologie et de Dynamique des Systèmes , (associá au C.N.R.S. -URA 34), Universitá Paris 7, 1, rue Guy de la Brosse, F-75005 , Paris , France;5. Dápartement de Chimie , Facultá des Sciences, Universitá C. A. Diop , Dakar , Sénégal |
| Abstract: | The electronic absorption and fluorescence spectra of 4-hydroxycoumarin, 7-hydroxycoumarin, 7-methoxycoumarin, 7-hydroxy-4-methylcoumarin, 7-amino-4-methylcoumarin, and 7-diethylamino-4-methylcoumarin were measured at room temperature (298K) in several solvents and their first excited singlet-state dipole moments were determined by the solvatochromic shift method. The excited singlet-state dipole moments of the coumarins were compared with the ground-state values. |
