Gold(I) Complexes of Secondary and Tertiary Amines. Crystal Structure of Triphenylphosphineaurio(I)quinuclidinium Tetrafluoroborate

The secondary amine piperidine and the tertiary amine quinuclidine (1-azabicyclo[2.2.2]-octane) were reacted in THF with one equivalent of triphenylphosphinegold(I) tetrafluoroborate, [Ph₃PAu]⁺ BF₄^–, to give the monoaurated ammonium salts of formula [R_nNH_(3-n)AuPPh₃]+ BF₄^– (n = 2, 3). The compounds were obtained as crystalline solids in good yields, and were characterized by IR and NMR spectroscopy as well as mass spectrometry and elemental analysis. The crystal structure of the quinuclidinium salt was determined (space group Pbca, Z = 8). The analysis shows independent formula units with no intermolecular Au…Au contacts. The Au (I)–N bond (2.11(1) Å) is significantly longer than the average value found in poly-aurated ammonium salts.