Potential of HF and CO₂ loss through dissociative electron attachment to increase radiosensitizers reactivity; case study on pentafluorobenzoic acid

Radiosensitizers reactions with low energy electrons, generated within malignant tissue in radiotherapy, may play a significant role in the efficacy of chemoradiotherapy. Specifically, in situ dissociative electron attachment to such radiosensitizers may cause effective frag-mentation and the formation of reactive species that, in turn, may cause DNA damage and cell death. In the current study we explore the potential of sensitizing molecular systems towards DEA, using the model compound pentafluoro benzoic acid. Dissociative electron attachment is studied experimentally and quantum chemical calculations are used to determine the threshold energies for the observed processes and to explore the vertical attachment energies and underlying orbital structures. We find that perfluorination significantly alters the fragmentation pattern of benzoic acid and enables efficient HF and CO₂ loss at very low attachment energies, leading to the formation of the complementary radical and closed shell anions. The efficiency of these processes is discussed in context to the respective thermochemistry and orbital structure and in the context of the potential of fluorination as means to tailor effective radiosensitizers.