K. Angermaier et H. Schmidbaur, PRIMARY AMINES AS NUCLEATION CENTERS FOR GOLD CLUSTERING, AND THE STRUCTURAL CHEMISTRY OF POLYGOLD AMMONIUM CATIONS, Journal of the Chemical Society. Dalton transactions, (4), 1995, pp. 559-564
Treatment of tert-butylamine and benzylamine with [Au(PR'3)]BF4 led to
the monoauration products [(R'3P)AuNH2R]+BF4- (R' = Me, R = Bu(t) 1a;
R' = Me, R = CH2Ph 1b; R'3 = Ph2Me, R = Bu(t) 1c). The salts [{Au(PMe
3)}3NR]+BF4- (R' = Me, R = Bu(t) 2a or CH2Ph 2b) derived from the same
amines were obtained using the corresponding oxonium salt [{Au(PMe3)}
3O]+BF4-. A diauration product [{Au(PMe3)}2NH(CH2Ph)]+BF4- 3 was gener
ated upon slow hydrolytic degradation of 2b in solution. Treatment of
NH(SiMe3)2 with [{Au(PMe3)}3O]+BF4- afforded both the tris- and tetra-
aurated ammonium salts, [{Au(PMe3)}3NSiMe3]+BF4- 2c and [{Au(PMe3)}4N]
+BF4- 4, depending on the reaction conditions. The cation of 2c is one
of the very rare examples of silylammonium species. Compound 4 was al
so obtained from the oxonium salt and ammonia. All compounds have been
characterized through analytical and spectroscopic data. The crystal
structures of 1a, 1c and 3 have been determined by X-ray diffraction m
ethods: 1c is a salt with monomeric gold ammonium cations, but 1a and
3 show supramolecular aggregation of the cations into dimers with shor
t intercationic Au ... Au contacts.