1 / 83

Fujita et al., 1994

Fujita et al., 1994. Fujita et al. Nature , 1994. molecular "magic rings". Fujita et al. The stoichiometry will induce the right selection of the fragments so as to afford a catenane quantitatively. Fujita et al.

zora
Download Presentation

Fujita et al., 1994

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Fujita et al., 1994

  2. Fujita et al. Nature, 1994

  3. molecular "magic rings" Fujita et al.

  4. The stoichiometry will induce the right selection of the fragments so as to afford a catenane quantitatively Fujita et al.

  5. The complexes contain two identical ligands but each ligand is asymmetric: the ring is oriented

  6. a catenane with two oriented rings Is it a chiral compound?

  7. a catenane with two 36-membered rings

  8. Angew. Chem. Int. Ed. 2005, 44, 4896 –4899

  9. Double-loop compound 2a was obtained by treating ligand 4 with bimetallic linker 5 in dimethyl sulfoxide (DMSO). Typically, ligand 4 (7.1 mg, 10 mmol) was treated with 5 (4.6 mg, 5.0 mmol) in DMSO (0.50 mL) for a few minutes at ambient temperature.

  10. Subsequently, the catenation of 2a at both loops by adding water to the solution in DMSO was examined. The newly formed product was cyclic dimer 3, which contains two catenated frameworks. Why do we need to add water??? 3 :

  11. CPK modeling showed that an expanded conformation of 3 has an external diameter of approximately 4 nm (Figure 5). The backbone of 3 comprises 238 non-hydrogen atoms

  12. Guest = o-Carborane

  13. O M e M e O M e O O O O + O O O O M e O M e M e O Free cage P d * * N * * Complexed cage 3 4 2 1 N N 5 6 8 9 7 10 11 12 N N N P d P d

  14. three very simple bridging ligands

  15. Analogy with C60 Schematic representation of the self-assembly of coordination networks from metal ions which favor a square-planar coordination geometry and different bridging ligands. a) Linear ligands are expected to give 2D grid complexes. b) Slightly bent ligands are expected to lead to spherical finite complexes.

  16. The 1H NMR spectrum (aromatic region) of the product Assembled from Pd(NO3)2 and ligand 1a (2 equiv; 500 MHz, [D6]DMSO, 258°C, TMS).

  17. CSI-MS spectrum showing the formation of M12L24 product (PF6 salt).

  18. a) Molecular structure 2a assembled from 24 bidentate ligands 1a and12 metal ions. b) Schematic representation of the cuboctahedral frameworks of 2a.

  19. a) STM image of individual spheres 2a on the graphite at room temperature. b) Height profile of the STM image.

  20. The crystal structure of 2b. Counterions and solvent molecules are omitted for clarity (green Pd, red O, blue N, gray C).

  21. By attaching a functional group on each ligand, 24 functional groups are aligned equivalently at the periphery of the sphere. Metal–porphyrins are known to collect light energy when they are aggregated as in light harvesting proteins or chlorophylls.

  22. A molecular modeling study of 2d : Pd yellow , the porphyrin-based and pyridine-based units are green and purple, respectively

More Related