PHENALENONE, A UNIVERSAL REFERENCE COMPOUND FOR THE DETERMINATION OF QUANTUM YIELDS OF SINGLET OXYGEN O2(1-DELTA-G) SENSITIZATION

The aromatic ketone phenalenone (PH) is shown to be a universal refere nce compound for the determination of quantum yields Q(DELTA) of O-1(2 ), sensitization. Values of Q(DELTA) of PH have been determined by pho tochemical, photoacoustic and near-IR luminescence methods. Q(DELTA) v aries in 13 solvents of very different physical and chemical propertie s and in methanol-water mixtures only in the narrow range 0.94 less-th an-or-equal-to Q(DELTA) less-than-or-equal-to 1.00. Extrapolations to air-saturated organic solvents and to O2-saturated micellar systems of low viscosity should be possible assuming Q(DELTA) = 0.95 +/- 0.05.