Synthesis and Characterization of Poly‐NHC‐Derived Silver(I) Assemblies and Their Transformation into Poly‐Imidazolium Macrocycles

Three metallosupramolecular assemblies composed of two bis‐NHCs and two silver atoms, [ 4 ](PF 6 ) 2 , two tetra‐NHCs and four silver atoms, [ 7 ](PF 6 ) 4 , and two tri‐NHCs and three silver atoms [ 8 ](BF 4 ) 3 , have been prepared. Assemblies [ 4 ](PF 6 ) 2 and [ 7 ](PF 6 ) 4 feature NHC ligands decorated with terminal olefin groups. Irradiation of [ 4 ](PF 6 ) 2 yielded complex [ 5 ](PF 6 ) 2 with two terminal cyclobutane rings linking the two bis‐NHC ligands. Liberation of the macrocyclic tetrakisimidazolium salt H 4 ‐ 6 (PF 6 ) 4 was achieved by reaction of [ 5 ](PF 6 ) 2 with NH 4 Cl/NH 4 PF 6 . No [2+2] cycloaddition was observed upon irradiation of [ 7 ](PF 6 ) 4 , apparently due to an unfavorable orientation of the olefin groups. Irradiation of complex [ 8 ](BF 4 ) 3 with three internal pairs of olefin groups leads to [ 9 ](BF 4 ) 3 as a mixture of two isomers that differ on the relative orientation of the internal cyclobutane rings. Reaction of [ 9 ](BF 4 ) 3 with NH 4 Cl/NH 4 BF 4 yields an isomer mixture of the novel cage‐line hexakisimidazolium salt H 6 ‐ 10 (BF 4 ) 6 .