ON TRIS[(TRIALKYLPHOSPHINE)GOLD(I)]OXONIUM TETRAFLUOROBORATES AND TRIS[(TRIPHENYLPHOSPHINE)GOLD(I)]SULFONIUM TETRAFLUOROBORATE

[Et3PAu]+BF4-, obtained from Et3PAuCl and AgBF4 in tetrahydrofuran, reacts with KOH (molar ratio 3:1) to give the oxonium salt [(Et3P)Au]3O+BF4- (1). The homologous [(tBu3P)Au]3O+BF4- (2) is generated similarly from tBu3PAuCl and Ag2O in the presence of NaBF4 in THF. The composition and identity of these two first tris[(trialkylphosphine)gold(I)]oxonium salts have been confirmed by analytical and spectroscopic data. The compounds are useful aurating agents. From the corresponding triphenylphosphine complex and (Me3Si)2S quantitative yields of the sulfonium salt [(Ph3P)Au]3S+BF4- (3) are obtained. Its crystal structure features monomeric cations, and in these small Au-S-Au angles indicate significant metal-metal bonding.