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-1(PF) reacts with AgO in CHCN to yield the [2]catenane [Ag(1)](PF). The [2]catenane rearranges in DMF to yield two metallamacrocycles [Ag(1)](PF). 2,7-Fluorenone-bridged bis-(imidazolium) salts H-L(PF) (L=2 a, 2 b) react with AgO in CHCN to yield metallamacrocycles [Ag(L)](PF) with interplanar distances between the fluorenone rings too small for [2]catenane formation.

N-Heterocyclic carbenes and their precursors in functionalised porous materials.

Though N-heterocyclic carbenes (NHCs) have emerged as diverse and powerful discrete functional molecules in pharmaceutics, nanotechnology, and catalysis over decades, the heterogenization of NHCs and their precursors for broader applications in porous materials, like metal-organic frameworks (MOFs), porous coordination polymers (PCPs), covalent-organic frameworks (COFs), porous organic polymers (POPs), and porous organometallic cages (POMCs) was not extensively studied until the last ten years. By or post-synthetic modification (PSM) methods, myriads of NHCs and their precursors containing building blocks were designed and integrated into MOFs, PCPs, COFs, POPs and POMCs to form various structures and porosities. Functionalisation with NHCs and their precursors significantly expands the scope of the potential applications of porous materials by tuning the pore surface chemical/physical properties, providing active sites for binding guest molecules and substrates and realizing recyclability.