Photophysics and chemistry at PAH compounds. Progress and proposed technical program

The work can be divided into four main areas that represent the evolution of biological and material damage from radiation and environmental impacts. The four areas are as follows: Part I deals with early events in radiation absorption in polycyclic aromatic hydrocarbons (PAH) that precedes chemical changes. The major components in this phase are electronically excited states, such as excitons and charge carriers. This includes theoretical and experimental studies; in some cases, the model compounds used are not PAH compounds, but are molecular solids that exhibit properties that should also exist in the PAH compounds. In Part II, we discuss particulate photophysics in which our photoemission studies play a major role. Here too, there are fundamental theoretical and experimental aspects. In Part III, we discuss the chemical reactions produced by the interaction of electronically excited states of PAH compounds with aqueous systems, and in Part IV, we discuss the reactions of PAH compounds and their derivatives that precede biological damage in living systems. As mentioned in our previous report, all of the above are relevant to an understanding of the mechanism of environmentally induced damage to living systems, either by radiation or by the products of combustion. In addition, some more » possible strategies for breaking the chain that leads to biological damage flow from our results. « less