Quantum Yield of Photosensitized Singlet Oxygen (a1.DELTA.g) Production in Solid Polystyrene

The quantum yield of singlet oxygen (a[sup 1][Delta][sub g]), produced by energy transfer from the photosensitizer acridine, has been determined by two independent spectroscopic methods in solid polystyrene. Upon 355-nm pulsed-laser irradiation of acridine at 1.3 mJ/pulse, the O[sub 2](a[sup 1][Delta][sub g]) quantum yield in polystyrene [[phi][sub [Delta]][sup PS](acridine) = 0.56 [+-] 0.05] is slightly smaller than that in a liquid solvent analog such as benzene [[phi][sub [Delta]][sup benz](acridine) = 0.83 [+-] 0.06]. These data indicate that the photosensitized yields of O[sub 2](a[sup 1][Delta][sub g]) in a solid polymer matrix can nevertheless be appreciable, which may be important for understanding the photodegradation of some polymeric materials or dyes and other additives dissolved in those materials.