A novel [FeII2L3]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.

A novel helicate complex [FeII2L3]4+ resulted from subcomponent self-assembly of a C3-symmetric triamine, 2-formylpyridine and octahedral iron(II) in CH3CN, which was confirmed by ESI-MS measurement. After the addition of selected planar aromatic molecules in CD3CN solution, shifts of 1H NMR signals of the helicate were investigated. The results revealed that the size, functional group and symmetry of guest molecules remarkably influence the interaction patterns.