Novel Mixed Coordination of N and C Donors to Gold–Gold Centers

This is the authors' abstract. We don't add key points for this paper.

Mixed-ligand gold(I) compounds featuring N and C connectivity from two dissimilar ligands, a formamidinate and a phosphorus ylide, are obtained by the reaction of a dinuclear gold(I) formamidinate with a phosphorus ylide in toluene solution under Schlenk conditions. When the reaction conditions such as polarity, basicity, and gold to ylide ratio are varied, a series of structures are produced, where the formamidinate (f = N, N ′-bis(2,6-dimethylphenyl)methanimidamide) invariably bridges gold(I) centers. The aurophilic distances of Au(I)···Au(I) range around 3.00 Å, whereas the ylide (dimethyldiphenylphosphonium, [H 2 y] + ) is monocoordinated as [Hy]. This produces open dinuclear species, with two terminal Hy's as the cation [Au 2 f(Hy) 2 ] + ( 1 ), with the nitrate anion or terminal Hy and chloride anion in [Cl-Au 2 f(Hy)] ( 2 ), or Hy and phenyl in [Ph-Au 2 f(Hy)] ( 3 ). The activation of the ylide ligand by base liberates the phenyl group which produces 3 . A related cationic mononuclear moiety [Au(Hf)(Hy)] ( 4 ), with neutral amidinate and ylide, is produced from the neutral amidine upon reaction with [Au(THT)Cl] in a THF solution of ylide. These new compounds have been characterized by X-ray crystal structures, 1 H NMR, IR, and elemental analysis.