On the Reactivity of NHCtBuAuCl towards Rb6Cs6Si17: The First Gold-Silicon Cluster [(NHCtBuAu)6(η2-Si4)]Cl2•7NH3 and an Imide Capped Gold Triangle (NHCtBuAu)3NHCl

Crystals of the two new compounds ((NHCAu)-Au-tBu)(3)NHCl and [((NHCAu)-Au-tBu)(6)(eta(2)-Si-4)]Cl-2 center dot 7NH(3)could be isolated from the reaction of Rb(6)Cs(6)Si(17)with (NHCAuCl)-Au-tBu in the presence of [2.2.2]-cryptand in liquid ammonia. Both compounds were characterized by single-crystal X-ray diffraction and crystallize trigonally without any alkali metals or chelating ligands. Additionally, the crystal of [((NHCAu)-Au-tBu)(6)(eta(2)-Si-4)]Cl-2 center dot 7NH(3)was further interpreted by means of ELF and NBO calculations. In the case of ((NHCAu)-Au-tBu)(3)NHCl, NMR experiments provided an exceptional insight into the reaction processes in solution and allowed for the detection of sequential precursors. In the class of capped gold triangles ((NHCAu)-Au-tBu)(3)NHCl impresses with its unique characteristics of being capped by an imide and bound toN-heterocyclic carbenes as ligands instead of the ubiquitously employed phosphines. The gold capped silicon tetrahedron [((NHCAu)-Au-tBu)(6)(eta(2)-Si-4)]Cl-2 center dot 7NH(3)represents the first known silicide-gold compound, as well as the first known functionalized Zintl anion, crystallized with a cationic central moiety.