Homo- and Heteroligand Poly-NHC Metal Assemblies: Synthesis by Narcissistic and Social Self-Sorting

Homoleptic and heteroleptic cylinder-shaped poly-NHC metallosupramolecular assemblies [Ag-3(L)(2)](BF4)(3) have been prepared by control of the shape, size, and electronic properties of disk-shaped trisimidazolium salts of type H-3-L(BF4)(3). Both imidazolium salts with an electron-deficient triazine backbone H-3-A(BF4)(3) or an electron-rich benzene backbone H-3-D(BF4)(3) have been employed. Reaction of H-3-A(BF4)(3)or H-3-D(BF4)(3) with Ag2O yield trinuclear homoligand complexes [Ag-3(L)(2)](BF4)(3) (L= A, D). However, equimolar mixtures of H-3-A(BF4)(3) and H-3-D(BF4)(3) react with Ag2O under social self-sorting to give the heteroligand assembly [Ag-3(A)(D)](BF4)(3). The same heteroligand assembly was obtained by transmetallation from mixtures of complexes [Ag-3(A)(2)](BF4)(3) and [Ag-3(D)(2)](BF4)(3). The transmetallation from [Ag-3(A)(D)](BF4)(3) to [Au-3(A)(D)](BF4)(3) is also demonstrated. The study expands to concepts of narcissistic and social self-sorting from classical Werner-type ligands to organonzetallic NHC chemistry thereby opening new routes for the construction of poly-NHC metal assemblies with increasing complexity.