Radiation induced effects in organic systems. Progress report, December 1, 1979-December 1, 1980

Progress was made in two areas of interest: the nature of the decay kinetics in systems yielding geminate radical pairs upon irradiation, and OH reactions with aromatic hydrocarbons. The work on geminate pairs has focused on the p,p' azoxy phenetole molecule, studied at low temperatures using both polycrystalline and single crystal systems. The result obtained appear to be somewhat different from those for the p,p' azoxy anisole system reported on earlier. Preliminary results on both microwave power saturation studies and decay kinetics suggest that the species stable only at low temperatures is not behaving as one would expect of geminate pairs. The gas-phase OH reactions have now been modified to produce reproducible results which can be interpreted as occurring in the bulk rather than as surface-modified. The most surprising result has been the observation of relatively large amounts of biphenyl produced from benzene by OH radical attack. This product has not been hither to reported and may be of significance in connection with the growing concentrations of substituted biphenyls in the environment