Ionizing Radiation and Natural Constituents of Living Cells: Low-Energy Electron Interaction with Coenzyme Q Analogs

Resonance electron attachment to short-tail analogs of Coenzyme Q10 is investigated in the electron energy range 0-14 eV under gas-phase conditions by means of dissociative electron attachment spectroscopy. Formation of long-lived (milliseconds) molecular negative ions is detected at 1.2 eV but not at thermal energy. A huge increase of the electron detachment time as compared with the reference para-benzoquinone (40 µs) is ascribed to the presence of the isoprene side chains. Elimination of a neutral CH3 radical is found to be the most intense decay detected on the microsecond time scale. The results give some insight into the timescale of electron-driven processes stimulated in living tissues by high-energy radiation and are of importance in prospective fields of radiobiology and medicine.