Electron attachment to trans-azobenzene
Abstract
The temporary anion states of gas-phase
The total anion current at the walls of the collision chamber and the mass-selected molecular anion current are also reported as a function of the impact electron energy. In agreement with previous data, long-lived (>1 μs) parent molecular anions are detected at zero eV and near 1 eV. The close similarity of the electron transmission spectrum with the derivatives with respect to energy of the anion currents suggests strongly that shape resonances produced by electron capture into empty π* orbitals are the initial step in formation of the long lived molecular anions. This appears to rule out mechanisms in which direct formation of core-excited anion states are invoked. However, according to DFT calculations, conversion of the shape resonances around 1 eV to longer-lived σ–π* core-excited doublet anion states is possible on energetic grounds.