Negative ion photoelectron spectroscopy of copper hydrides

We report photoelectron imaging spectra of CuH and CuH 2 and their deuterated analogs. The CuH photoelectron spectrum exhibits transitions to the ground (X R) and lowest excited triplet (a R) and singlet (A R) states, with EA(CuH) 0.444(6) eV. The photoelectron spectrum of linear X Rg HCuH is dominated by a transition to the linear excited A Rg state with a 2.853 eV binding energy. It is accompanied by an extended unresolved vibrational progression involving the bent CuH2 X B2 ground state. Ab initio calculations show a 0.255 eV energy difference between these two states allow determination of EA(CuH2), 2.60(5) eV. 2007 Elsevier B.V. All rights reserved.