Absolute Quantum Yields and Lifetimes of Photosensitized Phosphorescence of Singlet Oxygen 02 ( 1 (g ) in Air-Saturated Aqueous and Organic Solutions of Phenalenone

The absolute quantum yield ( (P of singlet oxygen ( 1 O2 )phosphorescence sensitized by phenalenone (PH) was determined together with the lifetime (in 19 different solvents.using the known (p =(1.38 ± 0.05) x 10 -3 in CCl4 as a standard. Measurements of both (P and ( were performed by combined use of a pulsed laser and a photon-counter coupled with a near-IR-sensitive photomultiplier. The (P value in water was determined to be (P =(4.5 ± 0.2) x 10 -8