Aurophilicity-Triggered Assembly of Novel Cyclic Penta- and Hexanuclear Gold(I) Complexes with Rigid Anionic NHC-Type Ligands

摘要

The products of the reaction between N,N'-diphosphanylimidazol-2-ylidene (P-C-P) and gold(I) precursors depend on the nature of the anions associated with the latter. In contrast to the reported reaction with [Au(tht)2(OTf)], the use of [AuCl(tht)] led to the new hexanuclear complex 1, which features a Au-6(mu 3-P-C,kappa C,kappa N,kappa P)(3) skeleton. The reaction of lithium imidazolide (P-C-Li) and [AuCl(tht)] also afforded 1, together with an unusual salt of the general formula [Au5Cl(mu(3)-P-C-kappa P,kappa C,kappa N)(3)](2)[AuCl2](2) (2), which contains [Au-5(mu(3)-P-C-kappa P,kappa C,kappa N)](+) subunits. In the solid state, one of these Au5 cations is associated with an [AuCl2](-) anion, while two other cations interact through their unique dicoordinated N-Au-N center with a [AuCl2](-) anion, with the charge of the resulting monocation being compensated for by another [AuCl2](-) anion to give a Au-12 salt. Remarkably, the latter displays seven different bonding types at Au-I: C-Au-C, N-Au-N, P-Au-P, Cl-Au-Cl, C-Au-N, P-Au-Cl, and Au center dot center dot center dot Au.