CALORIMETRIC DETERMINATIONS OF ABSOLUTE FLUORESCENCE QUANTUM YIELDS

The absolute fluorescence quantum yields, φf, of a number of highly fluorescent organic dyes and aromatic compounds have been measured in various solvents, utilizing a calorimetric technique in which the heating rates under monochromatic irradiation are compared for the fluorescent solution and for an inert reference absorber. The technique yields the absolute fluorescence yield for air-saturated solutions with an accuracy of ±0.02. The compound/solvent systems studied provide reference fluorescence values of 0.50 or greater for solvents of refractive index varying between 1.33 and 1.50 and at excitation wavelengths ranging from 366 to 633 nm. © 1979 American Chemical Society.