UV-Vis absorption spectra of trapped electrons and radicals induced by X-ray irradiation. (a) Difference spectra between absorption spectra of an oxyferrous P450cam crystal before and during irradiation. The creation and decay of a broad spectrum of trapped solvated electrons within the first few seconds can be observed. Spectra were acquired with a time interval of 0.2 s. (b) The concentration of radicals, absorbing at 321 nm, increases linearly with time. At the beginning there is an overlap with the absorption band associated with the trapped electrons. (c) In contrast, the concentration of trapped solvated electrons, which absorb at 676 nm, increases quickly and decays again.