Self-Assembly of Supramolecular Fractals from Generation 1 to 5

J Am Chem Soc. 2018 Oct 31;140(43):14087-14096. doi: 10.1021/jacs.8b05530. Epub 2018 Oct 5.

Abstract

In the seeking of molecular expression of fractal geometry, chemists have endeavored in the construction of molecules and supramolecules during the past few years, while only a few examples were reported, especially for the discrete architectures. We herein designed and constructed five generations of supramolecular fractals (G1-G5) based on the coordination-driven self-assembly of terpyridine ligands. All the ligands were synthesized from triphenylamine motif, which played a central role in geometry control. Different approaches based on direct Sonogashira coupling and/or ⟨tpy-Ru(II)-tpy⟩ connectivity were employed to prepare complex Ru(II)-organic building blocks. Fractals G1-G5 were obtained in high yields by precise coordination of organic or Ru(II)-organic building blocks with Zn(II) ions. Characterization of those architectures were accomplished by 1D and 2D NMR spectroscopy, electrospray ionization mass spectrometry (ESI-MS), traveling-wave ion mobility mass spectrometry (TWIM-MS), and transmission electron microscopy (TEM). Furthermore, the two largest fractals also hierarchically self-assemble into ordered supramolecular nanostructures either at solid/liquid interface or in solution on the basis of their well-defined scaffolds.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Fractals
  • Ligands
  • Macromolecular Substances / chemical synthesis
  • Macromolecular Substances / chemistry
  • Molecular Structure
  • Particle Size
  • Pyridines / chemical synthesis*
  • Pyridines / chemistry
  • Surface Properties

Substances

  • Ligands
  • Macromolecular Substances
  • Pyridines