Determination of structural parameters from advanced molecular electronic spectroscopy: the double ionization of nitrous oxide by synchrotron radiation

The double photoionization of N2O molecules, in the 30-50 eV energy range, has been studied by synchrotron radiation. In the whole energy range, dissociative ionization producing N+ + NO+ or N+2+ O+ has been observed. These two processes appear to occur also below the vertical threshold of 35.8 eV, where the double ionization should be indirect. In the range between 35.8 and 38.5 eV. The two processes occur instead by direct coulomb explosion of the N2O2+ dication. Above 38.5 eV, the dissociation leading to NO+ + N+ is also promoted by the formation of a dication metastable state, which decays by fluorescence to the ground state and then dissociates.