Dinuclear Au(I), Au(II) and Au(III) Complexes with (CF₂)_n Chains: Insights into The Role of Aurophilic Interactions in the Au(I) Oxidation

Abstract

New dinuclear Au(I), Au(II) and Au(III) complexes containing (CF 2 ) n bridging chains were obtained. Metallomacrocycles [Au 2 {μ-(CF 2 ) 4 }{μ-diphosphine}] show an uncommon figure-eight structure, the helicity inversion barrier of which is influenced by aurophilic interactions and steric constraints imposed by the diphosphine. Halogenation of LAu(CF 2 ) 4 AuL (L = PPh 3 , PMe 3 , (dppf) 1/2 , (binap) 1/2 ) gave [Au(II)] 2 species, some of which display unprecedented folded structures with AuÀ Au bonds. Aurophilic interactions facilitate this oxidation process by preorganizing the starting [Au(I)] 2 complexes and lowering its redox potential. The obtained [Au(II)] 2 complexes undergo thermal or photochemical elimination of R 3 PAuX to give Au(III) perfluorinated auracycles. Evidence of a radical mechanism for these decomposition reactions was obtained.

5‐Nitrofuryl‐Containing Thiosemicarbazone Gold(I) Compounds: Synthesis, Stability Studies, and Anticancer Activity

“…This redox signal can be associated to the oxidation of Au(I) to Au(II) of dimeric compounds stabilized by aurophilic interactions. [70,71] This oxidation process has also been reported for other gold(I)-HTSC compounds. [44,45] The presence of this redox signal (t = 0) confirms the low stability in solution of compound 4 (as described before).…”

“…[62] This bond distance falls in the range normally observed for gold(I) dimer compounds stabilized by aurophilic interactions. [65,66,69,71,74,75] The bidentate coordination of the thiosemicarbazone ligand through the sulfur atom and hydrazine nitrogen atom while not very common, has been reported for other metal complexes. [76] In addition, the formation of dimeric metal compounds with the 5-nitrofuryl containing thiosemicarbazone has also been reported.…”

Dynamic Au–C σ-Bonds Leading to an Efficient Synthesis of [n]Cycloparaphenylenes (n = 9–15) by Self-Assembly

“… The reaction of 4,4′-diphenyldiboronic acid ( L2 ) with [Au 2 Cl 2 (dcpm)] ( 1 ) (dcpm = bis­(dicyclohexylphosphino)­methane) produced the triangular hexagold­(I) complex [Au 2 (C 6 H 4 ) 2 (dcpm)] 3 ( Au-2 ) isolated in 77% yield. The oxidative chlorination − of Au-2 by PhICl 2 afforded [6]­CPP in a total yield of 59% (over two steps from 1 ). Thus, this synthetic method has the advantage of highly efficient synthesis of CPPs and related nanohoops from three arylene units. − However, the scope of this synthetic method and the mechanism of the efficient formation of the triangular Au complexes remain to be examined.…”

Digold(I) Thianthrenyl Complexes. Effect of Diphosphine Ligands on Molecular Structures in the Solid State and in Solution

“…This reaction has been employed to synthesize an aromatic macrocycle . The reaction involved oxidation of an intermediate digold­(I) complex with the bis­(dicyclohexylphosphino)­methane ligand . Complex 1 is thus expected to undergo both the oxidation at the two Au­(I) centers and the thianthrenyl ligands.…”