“Click” Assemblies and Redox Properties of Arene- and Gold-Nanoparticle-Cored Triazolylbiferrocene-Terminated Dendrimers

Large dendritic assemblies terminated by organometallic groups that possess a rich redox chemistry and stability in two or more oxidation states are highly desired as electron-reservoir systems, sensors, and redox catalysts. Here the synthesis and click (CuAAC) chemistry of ethynyl biferrocene including branching onto dendrons, arene-cored dendrimers, and gold nanoparticles are developed, and the role of the 1,2,3-triazole linkers and redox chemistry of these assemblies are discussed including the properties and stabilities of the redox states

<i>Meso</i>-Helicates with Rigid Angular Tetradentate Ligand: Design, Molecular Structures, and Progress Towards Self-Assembly of Metal–Organic Nanotubes

The self-assembly of two novel metallosupramolecular complexes of the general formulas [L₂M₂(CH₃CN)₄]­[BF₄]₄ (M = Co, <b>1a</b>; M = Ni, <b>1b</b>), where L stands for the tetradentate ligand 3,5-bis­[4-(2,2′-dipyridylamino)­phenylacetylenyl]­toluene, is reported together with their molecular structures ascertained by single-crystal X-ray diffraction studies. Complexes <b>1a</b> and <b>1b</b> are isostructural and show the formation of dinuclear <i>meso</i>-helicates with the two octahedral metal centers displaying respectively Δ and Λ configurations. These <i>meso</i>-helicates display large nanocavities with metal---metal separation distance of >2 nm; furthermore, π–π-stacking occurs among individual units to form one-dimensional (1D) polymers which further autoassemble in another direction through π–π contacts among neighboring chains to generate a two-dimensional (2D) network with regular nanocavities. Our approach might be of interest to prepare metal–organic nanotubes via a bottom-up strategy depending on the assembling functional ligand and the geometry of molecular building block