PRODUCTION OF SINGLET OXYGEN (1-DELTA-G O2) BY 9,10-DICYANOANTHRACENEAND ACRIDINE - QUANTUM YIELDS IN ACETONITRILE

Quantum yields for singlet oxygen (1DELTA(g), O2) production have been determined for the sensitizers 9,10-dicyanoanthracene (DCA) and acrid ine in acetonitrile (phi(DELTA)infinity(DCA)=2.06+/-0.40; phi(DELTA)in finity(acridine)=0.97+/-0.10). The DCA data are not consistent with a value recently published by Kanner and Foote. The acridine data are do cumented here for the first time. The importance of an accurate 1DELTA (g) O2 quantum yield standard for the polar solvent acetonitrile is di scussed in terms of published experiments designed to elucidate the ro le of charge-transfer states in the oxygen-organic molecule photosyste m.