Primary amines as nucleation centres for gold clustering, and the structural chemistry of polygold ammonium cations
摘要:
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(PMe3)}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 generated 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 also 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 methods: 1c is a salt with monomeric gold ammonium cations, but 1a and 3 show supramolecular aggregation of the cations into dimers with short intercationic Au ... Au contacts.
Primary amines as nucleation centres for gold clustering, and the structural chemistry of polygold ammonium cations
摘要:
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(PMe3)}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 generated 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 also 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 methods: 1c is a salt with monomeric gold ammonium cations, but 1a and 3 show supramolecular aggregation of the cations into dimers with short intercationic Au ... Au contacts.