¹H NMR STUDY OF THE HOST-GUEST CHEMISTRY IN A SUPRAMOLECULAR HELICATE FE^II₂L₃ SOLUTION

A novel [Fe^II₂L₃]⁴⁺ metallo-organic helicate results from subcomponent self-assembly of a C₃-symmetric triamine (4,4',4''- (1,3,5-triazine-2,4,6-triyl) trianiline), octahedral iron(II) and 2-formyl pyridine in CH₃CN solution. The constitution of this supramolecular helicate was confirmed by ESI-MS and ¹H NMR spectra. Different planar aromatic guests were selected to investigate host-guest interactions by shifts of ¹H NMR signals. The results show that electron-rich aromatic molecules with matched size and symmetry, such as pyrene, are subject to be bound with the outstretched arms of the helicate ligand via aromatic p–p interactions.

Keywords:
self-assembly; helicate complex; iron(II); host-guest chemistry