Preparation and Crystal Structures of Gold(I) Complexes of a Series of Benzenethiolates: Pair Formation by Gold‐to‐Gold Interactions of (Benzenethiolato)(triphenylphosphane)gold(I)

Chloro(triphenylphosphane)gold(I) reacts readily with benzenethiol C₆H₅SH and a series of sterically hindered (2,4,6‐trialkylbenzene)thiols 2,4,6‐R₃C₆H₂SH in the presence of NEt₃ to yield stable gold(I) complexes Ph₃PAu(S – 2,4,6‐C₆H₂R₃) [RH (1), Me (2), Et (3), iPr (4)]. The crystal structures of these complexes have been determined by single‐crystal X‐ray diffraction analysis. In all compounds the gold atoms are linearly two‐coordinate with very similar bond lengths and angles. – While complexes 2 – 4 with bulky thiolate ligands are monomeric in the crystal lattice, complex 1 has been found to form pairs of molecules with intermolecular gold – gold contacts of 313.5(5) pm. The Mössbauer spectra of the complexes exhibit large isomer shifts (I.S.), ranging from 3.06 to 3.72 mm s^–1, and quadrupole splittings (Q.S.), ranging from 7.90 to 8.68 mm s^–1. These data can be attributed to the strong electron‐donating properties of the benzenethiolate ligands. The gold – gold contacts in complex 1 lead to I.S. and Q.S. values which are slightly smaller than those of 2 – 4. The Au – S distances do not show a major influence of the S – Au – P pairing in complex 1 as compared to complexes 2 – 4.