4H-l-benzopyran-4-thione

Phosphorescence lifetimes of 2-amino-l-methyl-6-phenylimidazo[4,5-b]pyri-dine and benzo[f]quinoline increase with decreasing temperature in glucose glasses. A series of articles has addressed the properties of the excited triplet state of 4H-l-benzopyrane-4-thione in perfluoroalkane solvents.Delayed S2-S0 fluorescence arises via triplet-triplet annihilation. 

---