Photodetachment of Electrons from Amide and Arsenide Ions: The Electron Affinities of NH2· and AsH2 ·

Abstract

The relative cross section for the gas‐phase photodetachment of electrons has been determined for NH 2 − in the wavelength region 1195–1695 nm (1.04–0.73 eV) and for AsH 2 − in the wavelength region 620–1010 nm (2.00–1.23 eV). An ion cyclotron resonancespectrometer was used to generate, trap, and detect the negative ions. A 1000‐W xenon arc lamp with a gratingmonochromator was used as the light source, except for one series of experiments in which a tunable laser was employed. Single sharp thresholds were observed in both cross sections, with the result that the following electron affinity values have been determined: E.A. ( NH 2 ·) = 0.744 ± 0.022 eV and E.A. ( AsH 2 ·) = 1.27 ± 0.03 eV.