Luminescence of cytosine vapor excited by slow electrons

Excitation of gas-phase cytosine in collisions with slow electrons was studied using an optical spectroscopy technique. Emission spectra in the range 270-500 nm were obtained through electron impact at energies 25, 40, and 60 eV. Optical excitation functions of the four strongest emission bands in the energy range from the excitation threshold to 70 eV were also obtained. It was shown that the 289- and 307-319-nm bands were due to emission of an excited OH group of the molecule. The origin of the 326- and 338-nm emission bands was also identified.