Diphenyl(2-hydroxy-phenyl)phosphine and its trimethylsilyl ether as ligands for Gold(I) complexes

Diphenyl(2-hydroxy-phenyl)phosphine was introduced as a ligand for gold(I) halides and pentafluorophenyl gold(I) in order to probe the interplay of intra-and intermolecular interactions based on aurophilic (Au⋯Au) and hydrogen bonding. 1:1 complexes of the type Ph₂(2-HO-C₆H₄)P-Au-X with X = Cl, Br, C₆F₅ have been prepared and characterized by analytical and spectroscopic data. The crystal structure of the chloro complex (1) has been determined. In the lattice the molecules form dimers through O-H⋯Cl hydrogen bonds. Au⋯Au contacts are ruled out by steric congestion. Reaction of 1 with triethylamine yields a 1:1 adduct with O-H⋯NEt₃ hydrogen bonding. The trimethylsilyl ether of the title ligand also forms 1:1 complexes with AuCl, AuBr, AuI, and AuC₆F₅. The crystal structures of the chloro (5) and iodo (7) compound have been determined. In both cases the lattices are built from monomers which show only minor differences in their conformations. The silylether groups are not acting as intra-or intermolecular donor functions to the gold atoms.