Photooxidation of naphthalene and phenanthrene in hexane as an oil film on water

The photolysis of naphthalene and phenanthrene dissolved in n-hexane and spread as a liquid film on water in the presence of air leads to 30 % and 28 % of the substrate degradation respectively. The primary photopruducts of naphthalene are 3-phenyl-2-propenal and 2-carboxybenzaldehyde and that of phenanthrene are 9,10-phenanthrenequinone, 2-biphenyl carboxylic acid and 2-biphenyl aldehyde. In the illumination experiments with filters WG 305 (“300”), WG 395 (“388”) and WG 420 (“417”) the rate of degradation of both the chemicals was slow. The concentration of photoproducts increases when studied as function of illumination time.