215787-96-5Relevant academic research and scientific papers
Gold(III) derivatives with C(4)-aurated 1-phenylpyrazole
Minghetti, Giovanni,Agostina Cinellu, Maria,Vittoria Pinna, Maria,Stoccoro, Sergio,Zucca, Antonio,Manassero, Mario
, p. 225 - 232 (2007/10/03)
The reaction of 1-phenylpyrazole (HL), with gold(III) chloride has been studied. Besides a 1:1 adduct [Au(HL)Cl3] 1, where the ligand is bonded through the nitrogen atom, several C(4) aurated species have been isolated. Thus treatment of [AuCl3]2 with HL in dichloromethane solution affords a complex, [Au(L)Cl2.HCl]n, 2, where the gold atom is bonded to the 4-carbon atom of the pyrazole ligand. Deprotonation of complex 2 by means of the not coordinating base 1,8-bis(dimethylamino)naphthalene (proton sponge), B, affords the salt [BH][Au(L)Cl3], 3, whereas reaction of 2 with 3,5-Me2py and PPh3 (molar ratio 1:2) gives the neutral species trans-[Au(L)(3,5-Me2py)Cl2], 4, and cis-[Au(L)(PPh3)Cl2], 5, respectively. The structure of compound 4 solved by X-ray diffraction, unambiguously shows the anionic ligand L bonded to the gold ion through the C4 atom. Alternatively, compounds 4 and 5 can be obtained in two steps, i.e. deprotonation of 2 with NaOH to give [Au(L)Cl2]n, 6, and reaction of 6 with 3,5-Me2py and PPh3, respectively. The new species were characterized by elemental analyses, conductivity measurements, IR, NMR and FAB-MS spectroscopy.
