Cu+2 vibronic states at 0–1.4 eV from multiphoton ionization–photoelectron spectroscopy

Publisher Website
Google Scholar
Abstract
We have used resonant two‐photon ionization (R2PI) of cold Cu2 in a pulsed molecular beam in conjunction with time‐of‐flight photoelectron spectroscopy (TOF‐PES) to study the vibronic states of Cu+2 from 0–1.4 eV. The Cu+2 threshold of 7.899±0.005 eV agrees with the ionization energy previously inferred from R2PI spectral intensities. We cleanly resolve a pair of Cu+2 excited state vibrational progressions with origins at 1.143 and 1.256 eV above threshold; both have ω+e=252±17 cm−1. We assign these progressions as a 3d‐hole, 2Π spin–orbit pair. In addition, in the range 0–1 eV, we observe a dense set of at least 50 moderately well‐resolved bands which can be fit to a single progression with ω+e=187±8 cm−1 and ωex+e=0.7±0.2 cm−1. While this might be the anticipated 2Σ+g ground state, the intensity pattern (multipeaked envelope, with alternation of intensities in some regions) suggests the possibility of multiple low‐lying 3d‐hole electronic states of Cu+2.

This publication has 41 references indexed in Scilit: