Photoelectron imaging of copper and silver mono- and diamine anions

The results of photoelectron imaging experiments of Cu and Ag mono- and diamine anions are reported. The photoelectron images were recorded at two photon energies, 800 and 527nm. The vertical detachment energies of CuNH2− and AgNH2− are lower than those of the respective atomic metal ion and are measured to be 1.11±0.05 and 1.23±0.05eV, respectively. By contrast, the electron detachment energies for Cu(NH2)2− and Ag(NH2)2− are higher than those of the corresponding metal ion and are determined to be 1.48±0.05 and 1.85±0.05eV, respectively. Energy-dependent photoelectron anisotropy parameters are also reported. The photodetachment of the Cu and Ag mono- and diamine anions exhibit a cos2θ angular dependence relative to the direction of the laser polarization. The nature of the chemical bonding and the symmetry of the highest occupied molecular orbitals are discussed in relevance to the measured anisotropy parameters.