Radiation induced decomposition of chlorinated benzaldehydes in aqueous solution

The radiation-induced degradation of 2-, 3- and 4-chlorobenzaldehydes in neutral, aqueous, oxygenated solutions was studied. The initial G-values for the substrate degradation as well as for the formation of final products, such as chloride ions, formaldehyde and mixture of acids, were determined in dependence of the absorbed dose. It was found that the chloride position on the aromatic ring is a determining factor for the degradation process initiated by OH radicals. For the first three final products the ratios based on the initial G-values are increasing in the sequence 3-ClBzA:2-ClBzA:4-ClBzA, whereas for the acids formation this is: 2-ClBzA:4-ClBzA:4-CIBzA. Some initial reaction steps are given for illustration of initial degradation and formation of some final products. (C) 1999 Elsevier Science Ltd. All rights reserved.