Studies on Fluorescence Quenching, Decay Rate Parameters, Dipole Moment, Rotational Diffusion of 3-(benzo[d]thiazol-2-yl)-7-(diethylamino)-2H-chromen-2-one Laser Dye in Excited Singlet State: Temperature Effect.

The effect of temperature on the absorption and emission characteristics of 3-(benzo[d]thiazol-2-yl)-7-(diethylamino)-2H-chromen-2-one (3BT7D2H-one) laser dye in glycerol solvent has been studied by the steady-state method. Fluorescence intensity decreases with an increase in temperature and shifts towards a shorter wavelength. Parameters like fluorescence lifetime, rate constants, activation energy, and dipole moment (using the thermochromic method) are determined experimentally. Also, the temperature effect on rotational diffusion of 3BT7D2H-one laser dye is studied and also estimated theoretical and experimental hydrodynamic volumes.