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

Angew Chem Int Ed Engl. 2018 Nov 26;57(48):15767-15771. doi: 10.1002/anie.201810010. Epub 2018 Nov 2.

Abstract

Homoleptic and heteroleptic cylinder-shaped poly-NHC metallosupramolecular assemblies [Ag3 (L)2 ](BF4 )3 have been prepared by control of the shape, size, and electronic properties of disk-shaped trisimidazolium salts of type H3 -L(BF4 )3 . Both imidazolium salts with an electron-deficient triazine backbone H3 -A(BF4 )3 or an electron-rich benzene backbone H3 -D(BF4 )3 have been employed. Reaction of H3 -A(BF4 )3 or H3 -D(BF4 )3 with Ag2 O yield trinuclear homoligand complexes [Ag3 (L)2 ](BF4 )3 (L=A, D). However, equimolar mixtures of H3 -A(BF4 )3 and H3 -D(BF4 )3 react with Ag2 O under social self-sorting to give the heteroligand assembly [Ag3 (A)(D)](BF4 )3 . The same heteroligand assembly was obtained by transmetallation from mixtures of complexes [Ag3 (A)2 ](BF4 )3 and [Ag3 (D)2 ](BF4 )3 . The transmetallation from [Ag3 (A)(D)](BF4 )3 to [Au3 (A)(D)](BF4 )3 is also demonstrated. The study expands to concepts of narcissistic and social self-sorting from classical Werner-type ligands to organometallic NHC chemistry thereby opening new routes for the construction of poly-NHC metal assemblies with increasing complexity.

Keywords: polycarbenes; self sorting; supramolecular chemistry; transmetallation.