Gold Complexes with Difunctional Perfluoroalkyl Chains: Quantifying the Energy of Aurophilic Interactions in Flexible Open‐Chain Complexes

Abstract

The first binuclear AuI compounds containing bridging (CF2)n chains (n=4, 6, 8) and AuIII metallaperfluorocyclopentanes have been obtained by photoinitiated reactions of LAuMe (L=PPh3, PMe3, PCy3, or IPr) with α,ω‐diiodoperfluorocarbons. Complexes LAu(CF2)4AuL present an unusual looped structure stabilized by an aurophilic interaction for L=PMe3, PPh3, and PCy3. The study of their dynamic behaviour has provided new insights about the strength of aurophilic interactions in solution, allowing quantification of the energy of a single Au⋅⋅⋅Au interaction.

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

“…Reaction ]. [21] Remarkably, complex 20 and [Au 2 F 2 (μ-dfmt) 2 ] (dfmt = N,N'bis(2,6-dimethylphenyl)formamidinate), [51] are the only Au II fluorocomplexes reported. [52] The gold-bound fluorine atoms in 20 were evidenced in its 19 ].…”

“…Similar Au•••Au and CÀ H•••F interactions have been observed in the crystal structure of 1. [21] The molecule of 2 lacks any symmetry in its crystal structure, although the differences between both halves of the molecule are small. In agreement with this, at sufficiently low temperatures the 19 F NMR spectrum shows seven doublets corresponding to eight inequivalent 19 F nuclei, two of which are coincidentally isochronous.…”

“…An activation enthalpy of 49.1 kJ/mol was calculated by Eyring analysis, [48] which is significantly larger than the activation enthalpy determined for the helicity inversion of 1 (35.8 kJ/mol). [21] This difference is rationalized by considering that inversion of 1 can easily take place after breaking the Au•••Au and CÀ H•••F interactions and formation of an extended species, while in 2 the distance between both Au centers is constrained by the limited 2), H36-F7 2.49, H42-F2 2.38). [48] conformational mobility of the macrocycle, raising the activation energy.…”

Structural Diversity and Argentophilic Interactions in Small Phosphine Silver(I) Thiolate Clusters

“…Silver thiolate oligomers have a marked tendency to establish coordinative Ag−S bonds and Ag⋅⋅⋅Ag, argentophilic contacts [26] . While the nature and strength of the analogous aurophilic (Au⋅⋅⋅Au) interactions [27] have been extensively studied and their importance in the self‐assembly of gold‐based molecular and cluster materials has been proved, [28–34] the strength and nature of argentophilic interactions is much less explored [26,35–37] . In general, the occurrence of argentophilic interactions is mostly proposed over the base of van der Waals distances [38–41] .…”

Gold Complexes with Difunctional Perfluoroalkyl Chains: Quantifying the Energy of Aurophilic Interactions in Flexible Open‐Chain Complexes

“…ORTEP diagrams (thermal ellipsoids set at 50 % probability, H atoms omitted) showing the molecular structures of 1 c (top) and 1 d (bottom) [66]. …”