Anion photoelectron spectroscopy and density functional theory studies of AuCn−/0 (n=3−8): Odd-even alternation in electron binding energies and structures

Abstract

We measured the photoelectron spectra of AuC n− ( n=3−8) and conducted theoretical study on the structures and properties of AuC n−/0 ( n=3−8). It is found that the photoelectron spectra of AuC n− exhibit odd-even alternation. The spectral features of AuC3−, AuC5−, and AuC7− are much broader than those of AuC4−, AuC6−, and AuC8−. The vertical detachment energies of AuC3−, AuC5−, and AuC7− are lower than those of AuC4−, AuC6−, and AuC8−. The most stable structures of AuC n− ( n=3−8) are chain structures. The most stable structures of neutral AuC n ( n=3−8) are linear structures except that those of AuC3 and AuC5 are slightly bent. The calculated ∠AuCC angles, Au−C bond lengths, and the charges on Au atom also show odd-even alternations, consistent with the experimental observations.