New routes to halo-complexes of gold by halide exchange from Au2Cl6. Crystal and molecular structure of triphenylmethyl tetrachloroaurate(III), CPh3[AuCl4].

Anhydrous [Au2Br6] and Aul can be obtained by halide exchange from [Au2Cl6] with RX (X = Br or I, R = H or alkyl). The addition of [Au2Cl6] to CPh3Cl produces the ionic derivative [CPh3][AuCl4] whose crystal and molecular structure has been determined by X-ray diffraction. Crystal data: space group P2(1)/c, a = 8.225(3), b = 14.671(6), c = 16.738(8) angstrom, beta = 97.85(2)-degrees and Z = 4. Other organic chlorides RCl (R = Pr, SiMe3 or Bu(t)) react with [Au2Cl6] with a partial reduction to the mixed-valence chloride [Au4Cl8]. Addition of [Au2Cl6] to anhydrous iron(III) chloride produced a mass-spectrometrically active mixed iron-gold species.