Photoelectron imaging spectroscopy of Cu−(H2O)1,2 anion complexes

We report high resolution photoelectron imaging spectra of Cu− and Cu−(H2O)n (n = 1,2) complexes. With the least bound electron principally localized on the metal, electron photodetachment produces neutral states that are best characterized by the atomic metal state plus a water molecule: [Cu (2S), H2O], [Cu (2D5/2), H2O], and [Cu (2D3/2), H2O]. The large Cu−-H2O separation gives rise to a remarkably narrow, isolated peak in the photoelectron spectrum, allowing an accurate, direct determination of the anion dissociation energy; when coupled with electronic structure calculations for the neutral, the adiabatic electron affinity is derived.