Oxidative Rearrangement in Gold Organometallics

Abstract

The one-electron oxidizing agent [NO]PF 6 was reacted with Bu 4 N[Au(C 6 X 5 ) 2 ] (X = F, Cl) complexes in CH 3 CN. The gold(III) complexes [Au(C 6 F 5 ) 3 (CH 3 CN)] and cis-[Au(C 6 Cl 5 ) 2 (CH 3 CN) 2 ]PF 6 were synthesized by the oxidation of gold(I) to gold(III) with the concomitant ligand rearrangement "oxidative rearrangement". The supramolecular crystal packing in the perfluorinated aryl gold(III) complex is dictated by the notably short C(sp 2 )−F···H(CH 3 CN) bond distance. The [Au(C 6 Cl 5 ) 2 (CH 3 CN) 2 ]PF 6 complex exhibits antisymbiosis, displaying equal ligands in the cis position. The electrochemical oxidation of Bu 4 N[Au(C 6 X 5 ) 2 ] (X = F, Cl) complexes in CH 3 CN showed two irreversible peaks at 0.71 and 1.21 V (X = F) and at 0.65 and 0.91 V (X = Cl) vs Ag/AgCl.

Synthesis, Photochemical, and Redox Properties of Gold(I) and Gold(III) Pincer Complexes Incorporating a 2,2′:6′,2″-Terpyridine Ligand Framework

“…Thus, the N–Au–N angles are narrower than the ideal square-planar coordination, showing values of only 80.60(11), 80.88(11), and 161.45(11)°, which are slightly narrower than those previously described for related gold(III) complexes containing terpy or terpy derivatives as ligand (with an average N–Au–N angle of 81.35° for the cis N–Au–N angles and of 162.65° for the trans N–Au–N angles). 5 − 10 The Au–C bond distance of 2.028(3) Å compares well with most of the Au III –C bond lengths of pentafluorophenyl groups trans to N-donor ligands previously described (from 1.980(17) to 2.043(10) Å) 27 − 32 and is identical to those found in [Au(C 6 F 5 ) 3 (FcCH 2 NHpyMe)] [Fc = (η 5 -C 5 H 5 )Fe(η 5 -C 5 H 4 )] (2.026(6) Å) 28 or in [Au(C 6 F 5 ) 2 (4-Mepy) 2 ](ClO 4 ) (2.030(9) Å). 27 The Au–N bond lengths within the cation are inequivalent, with the central Au–N distance trans to pentafluorophenyl (1.985(3) Å) shorter than the Au–N distances observed for the two nitrogen atoms trans to each other (2.025(3) and 2.028(3) Å), which is surprising considering the higher trans influence of the aryl group if compared to N-donor ligands.…”

Polarized Supramolecular Aggregates Based on Luminescent Perhalogenated Gold Derivatives

“…Both crystal structures consist of linear [(aryl)­Au­(PR 3 )] molecules, which in the case of complex 1 are associated in pairs via aurophilic interactions of 3.1173(4) Å (Figures and S13). The aurophilic interaction observed in 1 is shorter than those reported for related gold­(I) derivatives with PTA, − which vary from 3.1388(11) Å in [Au­{CC–C­(Me)­(Et)­OH}­(PTA)] and 3.457(1) Å in [Au­(PTA) 2 ]­[Au­(CN 2 )] or those in [Au­{7-(prop-2-ine-1-yloxy)-1-benzopyran-2-one}­(DAPTA)] [3.1274(4) and 3.1316(4) Å], and it is only longer than that in [Au­({SPh­(3,5-Cl 2 )}­(PTA)], which displays a Au–Au distance of 3.0468(10) Å. The Au–P and Au–C distances are similar to the distances of other reported Au I -PTA ,− and Au I -C 6 F 5 − complexes.…”

“…The aurophilic interaction observed in 1 is shorter than those reported for related gold­(I) derivatives with PTA, − which vary from 3.1388(11) Å in [Au­{CC–C­(Me)­(Et)­OH}­(PTA)] and 3.457(1) Å in [Au­(PTA) 2 ]­[Au­(CN 2 )] or those in [Au­{7-(prop-2-ine-1-yloxy)-1-benzopyran-2-one}­(DAPTA)] [3.1274(4) and 3.1316(4) Å], and it is only longer than that in [Au­({SPh­(3,5-Cl 2 )}­(PTA)], which displays a Au–Au distance of 3.0468(10) Å. The Au–P and Au–C distances are similar to the distances of other reported Au I -PTA ,− and Au I -C 6 F 5 − complexes. The C–Au–P angles of 169.3(1)° and 174.7(3)° for 1 and 2 , respectively, indicate some deviation from the usual linear geometry, as reported for analogous complexes. , In the case of complex 1 , this fact is probably caused by the aurophilic interaction.…”

Intimate relationship between C–I reductive elimination, aryl scrambling and isomerization processes in Au(iii) complexes

“…7 There are just a few reported cases of aryl scrambling phenomena involving Au( iii ) complexes. Those reported by Luzuriaga 8 (Scheme 1, middle) and Nevado 9 groups (Scheme 1, below), have in common that they are only detected when strong oxidants come into play, and are lacking any mechanistic investigation.…”