Trifluoromethylation of [AuF 3 (SIMes)] with the Ruppert-Prakash reagent TMSCF 3 in the presence of CsF yields the product series [Au(CF 3) x F 3Àx (SIMes)](x = 1-3). The degree of trifluoromethylation is solvent dependenta nd the ratio of the speciesc an be controlled by varying the stoichiometry of the reaction, as evidenced from the 19 FNMR spectra of the correspondingr eactionm ixtures.T he molecular structures in the solid state of trans-[Au(CF 3)F 2 (SIMes)] and [Au(CF 3) 3 (SIMes)] are presented, together with as elective route for the synthesis of the latter complex.C orrelation of the calculated SIMes affinity with the carbene carbon chemical shifti nt he 13 CNMR spectrum reveals that trans-[Au(CF 3)F 2 (SIMes)] and [Au(CF 3) 3 (SIMes)] nicely follow the trend in Lewis acidities of related organo gold(III) complexes. Furthermore, an ew correlation between the AuÀC carbene bond length of the molecular structure in the solid state and the chemical shift of the carbene carbon in the 13 CNMR spectrum is presented.

A new synthetic access to the Lewis acid [Au(OTeF5)3] and the preparation of the related, unprecedented anion [Au(OTeF5)4]− with inorganic or organic cations starting from commercially available and easy‐to‐handle gold chlorides are presented. In this first extensive study of the Lewis acidity of a transition‐metal teflate complex by using different experimental and quantum chemical methods, [Au(OTeF5)3] was classified as a Lewis superacid. The solid‐state structure of the triphenylphosphine oxide adduct [Au(OPPh3)(OTeF5)3] was determined, representing the first structural characterization of an adduct of this highly reactive [Au(OTeF5)3]. Therein, the coordination environment around the gold center slightly deviates from the typical square planar geometry. The [Au(OTeF5)4]− anion shows a similar coordination motif.

We report on a comprehensive reactivity study starting from [AuF3(SIMes)] to synthesize different motifs of monomeric gold(III) fluorides. A plethora of different ligands has been introduced in a mono‐substitution yielding trans‐[AuF2X(SIMes)] including alkynido, cyanido, azido, and a set of perfluoroalkoxido complexes. The latter were better accomplished via use of perfluorinated carbonyl‐bearing molecules, which is unprecedented in gold chemistry. In case of the cyanide and azide, triple substitution gave rise to the corresponding [AuX3(SIMes)] complexes. Comparison of the chemical shift of the carbene carbon atom in the 13C{1H} NMR spectrum, the calculated SIMes affinity and the Au−C bond length in the solid state with related literature‐known complexes yields a classification of trans‐influences for a variety of ligands attached to the gold center. Therein, the mixed fluorido perfluoroalkoxido complexes have a similar SIMes affinity to AuF3 with a very low Gibbs energy of formation when using the perfluoro carbonyl route.