Silylimido and Disilylamido Groups as Clustering Centers for (Phosphane)gold(I) Units: Aurated Silylammonium Cations

The reaction of hexamethyldisilazane with tris[(phosphane)‐aurio(I)]oxonium tetrafluoroborates affords the corresponding trinuclear μ 3 ‐trimethylsilylimido compounds of the type {[(R 3 P)Au] 3 NSiMe 3 } + BF −4 ( 1a‐f ). With ( triphenylsilyl )amine and the oxonium reagents the analogous series of Ph 3 Si derivatives ( 2a‐f ) is formed (R = Me, Et, iPr; R 3 = Ph2Me; R = Ph, o‐Tol). The Et 3 P‐based oxonium salt and (Me 3 Si) 2 NH give the dinuclear μ‐trimethylsilylamido complex {[(Et 3 P)Au] 2 N(SiMe 3 ) 2 ) 2 } + BF −4 (3) as the main product. The crystal and molecular structures of complexes 2a , 2e , and 3 were determined. The trinuclear cations have a pseudo‐tetrahedral structure with small Au‐N‐Au angles and short Au‐Au distances for the SiNAu 3 units. The Ph 3 SiN units in 2a and 2e are capping triangles of gold atoms, while in the cation of 3 the (Me 3 Si) 2 N unit is bridging a pair of gold atoms. In the 31 P‐ and 14 N‐NMR spectra of compounds 1 and 2 (except for 1f and 21 ) the coupling J ( 31 P, 14 N) is observed. This coupling is temperature‐dependent, owing to changes in the relaxation characteristics in solution at low temperature. The decomposition of compounds 1 and 2 leads to the formation of pentanudear dications {[(R 3 P)Au] 5 N} 2+ for R = Me, Ph.