Oxoaromatic compounds are known to be weak organic bases. In the ground electronic
state they are protonated in very acidic media (pH< 0)[1-4]. On excitation the basicity of …

The absorption and fluorescence spectra of three hydroxycoumarins have been determined
in anhydrous dimethylsulfoxide, tetrahyrofuran and acetonitrile. Minor absorption and …

The excited state protonation of the carbonyl group of 7-aminocoumarins, cotaining a 7-
amino group fixed in the yulolidine fragment, is an irreversible diffusion-limited process in …

The kinetics and mechanism of the reaction in the photo-excited state of 7-hydroxycoumarin
and its derivative have been studied in aqueous solutions by means of measuring the …

The ground-and excited-state protonation of Coumarin 102 (C102), a fluorescent probe
applied frequently in heterogeneous systems with an aqueous phase, has been studied in …

The absorption and fluorescence emission of substituted coumarins have been studied in
different solvents. It is observed that the substituents alter both the absorption and …

Abstract Interaction of Coumarin 1, its 3-aldehyde derivative, and biscoumarin with solvents
of varying acidity (water and ethanol with an alkali or acid admixture) was studied by …

Fluorescence spectra of 3-cyano-4-methyl-7-hydroxycoumarin were measured in ethanolic
solutions containing various amounts of water and acid. Spectra composed of two bands …

Coumarin 183 (C183) was used as a photoacid to study excited-state proton transfer (ESPT)
reactions. Here, we studied the effect of ions on the ESPT of C183 in aqueous NaCl …

The rate constant for protonation of the electronically excited state of coumarin 102 in water
has been determined to be (1, 4× 0.4)× 10 10 mol− 1 s− 1 using picosecond spectroscopy …