Photoelectron imaging and theoretical calculations of gold–silver hydrides: comparing the characteristics of Au, Ag and H in small clusters

Abstract

Structures and electronic properties of the mixed metal hydride anions AuAgH⁻, Au₂AgH⁻, AuAg₂H⁻ and their neutrals are studied using anionic photoelectron imaging and theoretical calculations. The three isomers of AuAgH⁻ are determined to be linear and those of AuAgH are determined to have C_s symmetry. The structures of Au₂AgH⁻, AuAg₂H⁻ and their corresponding neutrals are determined to be planar with C_s or C_2v symmetries. The vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) of these anions are reported. Similar to the homonuclear Au_m⁻ and Ag_n⁻ clusters, the metal hydride anions with an even number of valence electrons have higher VDEs than those with an odd number. Variation of the VDEs of these metal hydride anions with interchange of Au, Ag and H (for example Au_mAg_n⁻ → Au_m−1Ag_{n+ 1}⁻, or Au_m−1Ag_nH⁻) will be shown to be characterized by the electronegativities of Au, Ag and H. The results presented in this study provide important insights into the similar and different characteristics of these three elements in small clusters.