Unprecedented coordination chemistry of a chloro(phosphine)gold(I) complex: [(Ad2BnP)2Au][AuCl2]

The reaction of (tht)AuCl (tht = tetrahydrothiophene) with the bulky phosphine ligand Ad2BnP yields [(Ad2BnP)2Au][AuCl2] (1, Ad = 1-adamantyl, Bn = benzyl) as the first example of a 1:1 chloro(phosphine)gold(I) complex having an ionic structure both in solution and solid state. The crystal structure of 1 revealed that the Au(I) atom is linearly coordinated by the phosphorus atoms and effectively shielded from the surroundings by the bulky substituents of the phosphine ligand. For comparison, the analogous complex image (2, nBu = n-butyl) has been synthesized and analysed by single crystal X-ray diffraction. In its crystal, it has a common rod-like structure known from R3PAuCl complexes with bulky phosphine ligands.