The highest oxidation state of Au revealed by interactions with successive cl ligands and superhalogen properties of AuCln (n = 1–6) species

This study deals with a reinvestigation on the maximum oxidation state of gold. Density functional calculations are performed on geometries and stabilities of AuCl_n species for n = 1–6 in their neutral and anionic states. The calculations clearly reveal that the maximum oxidation state of Au is limited to +5. The high adiabatic electron affinities of AuCl_n (n ≥ 2), as compared to Cl, suggest their superhalogen behavior. The interaction of AuCl_n superhalogens with an alkali metal, K is found to be similar to but stronger than that between K and Cl, leading to the formation of KAuCl_n complexes. The stabilities of these complexes explore the possibility of synthesis of new class of salts by interaction of with appropriate metal cations. © 2014 Wiley Periodicals, Inc.