Gold(III) adducts of 2-vinyl- and 2-ethylpyridine and cyclometallated derivatives of 2-vinylpyridine: Crystal structure of the cyclometallated derivative [Au(k2-C,N–CH2CH(Cl)–C5H4N)(PPh3)Cl][PF6]

Reaction of Na[AuCl4] with 2-vinylpyridine (vinpy) and 2-ethylpyridine (etpy) affords the N-bonded adducts Au(Rpy)Cl3 (R = CH2CH, vinpy; CH3CH2, etpy). Cationic adducts, [Au(vinpy)2Cl][X]2 (X = BF4, PF6) and [Au(etpy)2Cl2][BF4], were also obtained by reaction of Au(Rpy)Cl3 with Rpy (1:1) and excess NaBF4 or KPF6. Thermal activation of Au(vinpy)Cl3 in water gives the five-membered cycloaurated derivative [Au(k2-C,N–CH2CH(Cl)–C5H4N)Cl2] formally resulting through a trans nucleophilic addition of a chloride onto the CC bond. No cyclometallated derivatives are obtained by reactions of Au(etpy)Cl3. An X-ray crystal structure determination on the PPh3 derivative [Au(k2-C,N–CH2CH(Cl)–C5H4N)(PPh3)Cl][PF6] was carried out.

Graphical abstractThermal activation of the 2-vinylpyridine adduct Au(vinpy)Cl3 in water gives the five-membered cycloaurated derivative [Au(k2-C,N–CH2CH(Cl)–C5H4N)Cl2] formally resulting through a trans nucleophilic addition of a chloride onto the CC bond. The PPh3 derivative [Au(k2-C,N–CH2CH(Cl)–C5H4N)(PPh3)Cl][PF6] has been structurally characterized.Figure optionsDownload full-size imageDownload as PowerPoint slide