Abstract
The electronic absorption, and emission spectra as well as fluorescence quantum yield of 3-(benzothiazol-2-yl)-7-hydroxycoumarin (BTHC) were measured in different solvents and are affected by solvent polarity (Δ
f). The deprotonation of BTHC by triethylamine is a reversible process. BTHC is relatively photostable, the quantum yield of photodecomposition (
φ
c) was found to be 2×10
−4 and 2.7×10
−4 in EtOH and DMF, respectively. The fluorescence lifetimes of BTHC were measured in the absence and in the presence of molecular oxygen and were found to be 2.82 and
2.78
ns
, respectively. BTHC acts as good laser dye upon pumping with nitrogen laser
(λ
ex
=337.1
nm)
in ethanol and gives laser emission with maxima at 508 and
522
nm
.