Electron attachment induced dissociation of the radiosensitizer molecule 1-(4-bromo-3-nitrophenyl)-1-propanone

Abstract 1-(4-bromo-3-nitrophenyl)-1-propanone (BNPP) is a proposed potential radiosensitizer that might combat hypoxia in tumor cells. Here, we study the electron-induced decomposition of BNPP in the gas phase using a crossed electron-molecular beam experiment supported by quantum chemical calculations. We show that the attachment of a single electron induces dissociation of the BNPP molecule, both directly and upon molecular rearrangement. The most prominent channel includes the formation of Br – at the electron energy of ∼0 eV, the parent anion is observed with an order of magnitude lower intensity. The formation of minor NO 2 – and [BNPP–NO] – fragments hints towards NO 2 pre-dissociation followed by its roaming in the vicinity of the [BNPP–NO 2 ] fragment, a mechanism already observed in other dissociative electron attachment studies.