Toward mechanical switching of surface-adsorbed [2]catenane by in situ copper complexation

J Am Chem Soc. 2007 Dec 19;129(50):15662-7. doi: 10.1021/ja075886m. Epub 2007 Nov 21.

Abstract

Using scanning tunneling microscopy (STM), electrospray ionization mass spectrometry (ESI-MS), and X-ray photoelectron spectroscopy (XPS), we demonstrate that a free [2]catenane consisting of two interlocking 30-membered rings (cat-30) can be deposited on a Ag(111) surface by vacuum sublimation without decomposition. The deposited cat-30 molecules self-organize as ordered dimer chain structures at the surface, presumably via intermolecular pi-pi stacking. An in situ addition of Cu atoms to the surface-adsorbed catenanes induces a drastic change in the molecular organization, i.e., from the dimer chain structure to isolated species. The nitrogen core level spectra suggest that the cat-30 phenanthroline units coordinate with Cu, indicating that the free catenane has been transformed into a Cu-complexed [2]catenane. Since it is known that the two interlocked macrocyclic rings of the free ligand cat-30 completely rearrange, i.e., circumrotate, upon complexation to copper, our results reveal that when adsorbed on the silver surface, the two macrocyclic rings of the free [2]catenane can glide within one another so as to generate the corresponding copper complex by in situ Cu complexation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Anthracenes / chemistry*
  • Copper / chemistry*
  • Ligands
  • Microscopy, Scanning Tunneling
  • Molecular Structure
  • Polycyclic Compounds / chemistry*
  • Spectrometry, Mass, Electrospray Ionization
  • Surface Properties

Substances

  • Anthracenes
  • Ligands
  • Polycyclic Compounds
  • catenane
  • Copper