Catenanes cyclophane ligands

Figure 13.19 Structure formulas of cyclophane ligand 214+, catenane ligands 224+ and 234+, and mononuclear catenane complexes.

In the case of L2" + it was not possible to synthesize [2]catenanes because the cavity of this cyclophane is too large to give stable complexes with aromatic crown ethers in the templated synthetic approach. Starting from Li" +, however, it was possible to prepare the [2]catenane ligands and L4 + which were then used to prepare several mononuclear [2]catenane complexes (Figure 23). These compounds were characterized by NMR spectroscopy, mass spectrometry and, in some cases, X-ray crystallography. 

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