Synthesis and Characterization of Mononuclear Amidogold(III) Complexes − Crystal Structure of [Au(N₂C₁₀H₇(CMe₂C₆H₄)‐6](NHC₆H₃Me₂‐2,6)][PF₆] − Oxidation of 4‐Methylaniline to Azotoluene

Abstract

Mononuclear amidogold(III) complexes [Au(C,N,N)(NRR′)][PF6] [C,N,N = N2C10H7(CMe2C6H4)‐6, where N2C10H8 = 2,2′‐bipy; R = H, R′ = p‐tolyl (5), o‐xylyl (6), isobutyl (7), sec‐butyl (8), R = R′ = Et (9)], [Au(C,N)(AcO)(NHC6H4NO2‐4)] (10) [C,N = NC5H4(CH2C6H4)‐2, where NC5H5 = py] and [Au(N,N)(NHC6H4NO2‐4)2][PF6] (11) (N,N = 2,2′‐bipy), have been synthesized in fairly good yields by reaction of the hydroxo, methoxo, or acetato complexes 1−4 {[Au(C,N,N)(OR)][PF6] [R = H (1), Me (2)], [Au(C,N)(AcO)2] (3), [Au(N,N)(OH)2][PF6] (4)} with amines. The structure of [Au(C,N,N)(NHC6H3Me2‐2,6)][PF6] (6) has been determined by X‐ray diffraction. Reaction of the hydroxo complex 4 with NH2C6H4Me‐4 gives metallic gold, the protonated ligand [N,NH][PF6] and organic products, the main one being azotoluene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Solution chemistry and cytotoxic properties of novel organogold(III) compounds

“…In the light of these observations, the gold(III) containing molecular fragment is very likely to be responsible for the observed cytotoxic effects, although the actual mechanism is not yet understood. 12 and [Au(pz Ph -H)Cl 3 ]K (AuPzCl). 13 The title compound was prepared according to Refs.…”

“…The structure in the solid state has been determined only for AuXyl; 12 6 ] with 2,6-xylidine and p-toluidine, respectively, show a significant enhancement of the hydrophobic properties compared to the parent complex. 12 In AuPyAcO the cyclometallated benzylpyridine provides a nitrogen and a carbon donor to the square planar gold(III) centre; the remaining coordination sites of the square plane being occupied by two acetate ligands. In AuPzCl the gold(III) centre is coordinated to a carbon atom of the 1-phenylpyrazole ligand and to three chlorides.…”

“…Indeed, these compounds can be quantitatively obtained by the reaction of [Au(bipy dmb -H)(OH)][PF 6 ] with an excess of the corresponding amines, only providing that water, produced by the reaction, is removed. 12 Solutions of AuPyAcO, either in water or in organic solvents, are colourless. When dissolved in water or in the reference buffer, AuPyAcO exhibits some characteristic bands in the near UV, around 260 nm that are stable with time.…”

“…Their growth inhibitory properties were analysed through the classical sulforhodamine-B method. 12 Results are shown in Table 1 exhibit significant variations in their cytotoxic properties against the tested cell lines, in spite of the fact that all of them most likely transform into the same species when dissolved in the reference buffer. This observation implies that the presence of the 2,6-Me 2 C 6 H 3 NH À or 4-MeC 6 H 5 NH À ligand affects somehow the biological activities of the common organogold(III) centre.…”

“…[Au(bipy dmb -H) (2,6- 12 [(Au(py dmb -H)(AcO) 2 ] (AuPyAcO) (in which py dmb = 2-(1,1-dimethylbenzyl)-pyridine) 12 and [Au(pz Ph -H)Cl 3 ]K (AuPzCl) (in which pz Ph = 1-phenylpyrazole). 13 The AuXyl and AuTol compounds, both featuring the same terdentate C, N, N ligand, inspired us by the encouraging results recently attained with the parent compound [Au(bipy dmb -H)(OH)][PF 6 ].…”