AbstractThree generations of metalated trigonal supramolecular architectures, so-called metallo-triangles, were assembled from terpyridine (tpy) complexes. The first generation (G1) metallo-triangles were directly obtained by reacting a bis(terpyridinyl) ligand with a 60° bite angle and ZnII ions. The direct self-assembly of G2 and G3 triangles by mixing organic ligands and ZnII, however, only generated a mixture of G1 and G2, as well as a trace amount of insoluble polymer-like precipitate. Therefore, a modular strategy based on the connectivity of ⟨tpy−Ru2+−tpy⟩ was employed to construct two metallo-organic ligands for the assembly of G2 and G3 Sierpiński triangles. The metallo-organic ligands LA and LB with multiple free terpyridines were obtained through Suzuki cross-coupling of the RuII complexes, and then assembled with ZnII or CdII to obtain high-generation metallo-triangular architectures in nearly quantitative yield. The G1–G3 architectures were characterized by NOESY and DOSY NMR spectroscopy, ESI-MS, TWIM-MS, and transmission electron microscopy.

Self-assembly of a metallo-organic ligand, composed of an inner uncomplexed 120°-bis(terpyridine) and an outer extended free 120°-bis(terpyridine) linked by a triple 〈-tpy-Ru2+-tpy-〉 connector, and complexed with Zn2+, gave rise to a discrete planar supramolecular honeycomb patterned fractal. The central metallo-hexagon was surrounded by six identical metallo-hexagons which perfectly mimicked the natural simple honeycomb structure.

A novel metallo-organic ligand [RuL2] with four uncomplexed coordination sites was created, and upon treatment with Zn2+ generated a dimetallic 3D metallosupramolecule in nearly quantitative yield. This self-assembly process gave stable intermediates, opening the pathway to the first 3D metallo-assembly possessing two Ru2+, two Fe2+, and two Zn2+ ions precisely located in the different edges. This strategy opens the door to novel designer 3D polymetallic constructs capable of diverse applications.

A polyterpyridinyl building block-based nutlike hexagonal bismetallo architecture with a central hollow Star of David was assembled by a stepwise strategy. This nanoarchitecture can be viewed as a recursive mathematical form that possesses a supramolecular corner-connected cyclic structure, i.e., a triangle or rhombus at various levels of scale or detail. The key metallo-organic ligand (MOL) with four uncomplexed free terpyridines was obtained by a final Suzuki cross-coupling reaction with a tetrabromoterpyridine Ru dimer. The molecular metallorhombus was prepared by reacting the MOL with a 60° bis-terpyridine and Fe2+. The giant hollow hexagonal nut with a diameter of more than 11 nm and a molecular weight of ca. 33 kDa was obtained in near-quantitative yield by mixing the two types of multi-terpyridine ligands with Fe2+. The supramolecular architecture was characterized by NMR (1H and 13C), 2D NMR (COSY and ROESY), and DOSY spectroscopies, high-resolution electrospray ionization mass spectrometry, traveling-wave ion mobility mass spectrometry, and transmission electron microscopy.

A Ru2+-connected, metallo-organic ligand (L) with three free terpyridines was designed and synthesized. L was assembled with Zn2+ to generate a helical structure; however, when mixing L with a 1,2,3-tristerpyridine ligand (T), a thermodynamically stable 2D rhombus was assembled. Furthermore, this 2D rhomboidal structure can also be achieved through the dynamic transformation of preassembled helix H with T and Zn2+ at room temperature.

Bismetallic triangles T4 (Ru2/Fe) and T5 (Ru2/Zn) were effectively prepared via a stepwise method from a 60°-bent bisterpyridne. Compared with obtaining T4 by mixing metallo–organic ligand L2 with Fe2+ directly and refluxing at a higher temperature (85 °C), the site to site metallo-transformation from T5 to T4 was employed at RT by simply adding Fe2+ to T5. The structures were fully confirmed by the NMR, ESI-mass, UV-vis absorption and emission spectroscopies.

Novel dibenzo[b,d]thiophene and dibenzo[b,d]furan-based bisterpyridine ligands have been synthesized and used to create unique metallomacrocycles. Direct self-assembly between the bisterpyridine ligands and Fe2+ led to a mixture containing multiple homo-metallomacrocycles. However, utilizing the robust Tpy(TpyRu2+Tpy)Tpy ligands, the metallo-organic ligands, coordination with Fe2+ resulted in the pure tetrameric bismetallo-macrocycles. Structures were characterized by 1H-NMR, COSY-NMR, DOSY-NMR, ESI-TOF-MS and UV/vis spectra.

The initial metallopolymer, derived from two different organic building blocks, is a kinetic intermediate to the final stable hexanuclear (bearing 4Ru2+ and 2Fe2+) metallomacrocycle obtained through a thermodynamic dis-assembly/re-assembly route. The heteroleptic metallomacrocyclic architecture was characterized by NMR, UV, IR, CV, 2D-ROESY, DOSY, and ESI-MS.

A bismetallo-organic polymer was successfully prepared by treating a metallo-ligand with Ag+; characterization was accomplished by NMR, UV-vis, and single crystal X-ray analyses. This heteronuclear polymer achieved more than a two-fold turnover number (TON) and a faster reaction rate in comparison to a Ce-driven Ru-monomer in catalytic water oxidation.

Novel terpyridine 1 was synthesized via Suzuki coupling; the resulting series of asymmetric conjugated terpyridine moieties were produced in good yield through subsequent UV irradiation. Oxidative cyclodehydrogenation was confirmed through isolation of the intermediate, proving the zippering cyclization in association with the aromatic conjugation expansion. The stepped conjugation could be controlled by choosing an appropriate solvent. The dimerization of terpyridine 1 was successfully introduced, making headway for these highly conjugated organometallic systems.

Based on two newly synthesized terpyridine-(1-methyl-pyridiniums) and their metallo-complexes, the exchangeable self-assembly behaviours of metallo-bisviologens with dibenzo-24-crown-8 ether (DB24C8) are comprehensively investigated.

The initial metallopolymer, derived from two different organic building blocks, is a kinetic intermediate to the final stable hexanuclear (bearing 4Ru2+ and 2Fe2+) metallomacrocycle obtained through a thermodynamic dis-assembly/re-assembly route. The heteroleptic metallomacrocyclic architecture was characterized by NMR, UV, IR, CV, 2D-ROESY, DOSY, and ESI-MS.

A series of terpyridine based Ru2+ complexes G1, G2, G3, and G4 were designed and synthesized, the solubility of complexes was enhanced by introducing a multiple tailed long aliphatic chain; full characterization has been performed with 1H NMR, 13C NMR, ESI-MS and UV-vis measurements. Electrochemical behaviours of these complexes have been investigated.

Self-assembly of a metallo-organic ligand, composed of an inner uncomplexed 120°-bis(terpyridine) and an outer extended free 120°-bis(terpyridine) linked by a triple 〈-tpy-Ru2+-tpy-〉 connector, and complexed with Zn2+, gave rise to a discrete planar supramolecular honeycomb patterned fractal. The central metallo-hexagon was surrounded by six identical metallo-hexagons which perfectly mimicked the natural simple honeycomb structure.

A Ru2+-connected, metallo-organic ligand (L) with three free terpyridines was designed and synthesized. L was assembled with Zn2+ to generate a helical structure; however, when mixing L with a 1,2,3-tristerpyridine ligand (T), a thermodynamically stable 2D rhombus was assembled. Furthermore, this 2D rhomboidal structure can also be achieved through the dynamic transformation of preassembled helix H with T and Zn2+ at room temperature.

Bismetallic triangles T4 (Ru2/Fe) and T5 (Ru2/Zn) were effectively prepared via a stepwise method from a 60°-bent bisterpyridne. Compared with obtaining T4 by mixing metallo–organic ligand L2 with Fe2+ directly and refluxing at a higher temperature (85 °C), the site to site metallo-transformation from T5 to T4 was employed at RT by simply adding Fe2+ to T5. The structures were fully confirmed by the NMR, ESI-mass, UV-vis absorption and emission spectroscopies.

A bismetallo-organic polymer was successfully prepared by treating a metallo-ligand with Ag+; characterization was accomplished by NMR, UV-vis, and single crystal X-ray analyses. This heteronuclear polymer achieved more than a two-fold turnover number (TON) and a faster reaction rate in comparison to a Ce-driven Ru-monomer in catalytic water oxidation.