Detection by Metastable Quenching Spectroscopy of Enhanced Back-Donation from a Ni(111) Surface to the2π*Orbital of Chemisorbed CO, Caused by Coadsorption of Potassium

Abstract
The influence of coadsorbed potassium atoms on the electronic structure of CO adsorbed on Ni(111) was studied by use of surface metastable quenching spectroscopy. An enhancement of electron emission from the partially filled 2π* antibonding orbital of CO is observed, and the result is interpreted in terms of increased electron back-donation from the metal to the 2π* orbital, caused by potassium atoms.