Synthesis of a Metalla[2]catenane, Metallarectangles and Polynuclear Assemblies from Di(N‐Heterocyclic Carbene) Ligands

The 2,7‐fluorenone‐linked bis(6‐imidazo[1,5‐ a ]pyridinium) salt H 2 ‐ 1 (PF 6 ) 2 reacts with Ag 2 O in CH 3 CN to yield the [2]catenane [Ag 4 ( 1 ) 4 ](PF 6 ) 4 . The [2]catenane rearranges in DMF to yield two metallamacrocycles [Ag 2 ( 1 ) 2 ](PF 6 ) 2 . 2,7‐Fluorenone‐bridged bis‐(imidazolium) salts H 2 ‐ L (PF 6 ) 2 ( L = 2 a , 2 b ) react with Ag 2 O in CH 3 CN to yield metallamacrocycles [Ag 2 ( L ) 2 ](PF 6 ) 2 with interplanar distances between the fluorenone rings too small for [2]catenane formation. Intra‐ and intermolecular π⋅⋅⋅π interactions between the fluorenone groups were observed by X‐ray crystallography. The strongly kinked 2,7‐fluorenone bridged bis(5‐imidazo[1,5‐ a ]pyridinium) salt H 2 ‐ 4 (PF 6 ) 2 reacts with Ag 2 O to yield [Ag 2 ( 4 )(CN)](PF 6 ), while the tetranuclear assembly [Ag 4 ( 4 ) 2 (CO 3 )](PF 6 ) 2 was obtained in the presence of K 2 CO 3 .