Determination of absolute photoionization cross-sections of nitrogenous compounds

The absolute photoionization cross-sections of 24 nitrogenous compounds were measured in the photon energy range from their respective ionization thresholds to 11.5   eV, including n -propylamine, iso -propylamine, n -butylamine, 2-butylamine, iso -butylamine, tert -butylamine, diethylamine, dibutylamine, triethylamine, aniline, benzylamine, n -methylaniline, cyclohexanamine, nitromethane, nitroethane, nitropropane, nitrobenzene, pyrrole, pyridine, pyrrolidine, morpholine, N , N -dimethylethanolamine, benzonitrile and benzeneacetonitrile. The experiments were performed by photoionization mass spectrometry with tunable synchrotron vacuum ultraviolet (VUV) light as an ionization source. Binary-liquid-mixtures of investigated and standard species were used in this measurement. As a good solvent, benzene was chosen as a calibration standard, since its photoionization cross-section had been well know. Moreover, photodissociative fragments were also presented.