Design and synthesis of dipyrrin complexes bearing unique structures, properties and functions

We first describe N₂O₂- type dipyrrins, which behave as tridentate or tetradentate ligands for the preparation of main- group- element complexes including B, Al, Si, Ge, and Sn. Similar complexes were unstable or hard to prepare using usual bidentate dipyrrins. In particular, the stable hypercoordinate dipyrrin- silicon complexes showed interconvertible photo- optical properties. The Ge and Sn complexes were obtained in a similar way. Ar,O - BODIPYs were also synthesized from the N₂O₂- type dipyrrins. Their application to a light harvesting molecular assembly is also shown. Second, we demonstrate the usefulness and potential of dipyrrin complexes in supramolecular chemistry. The one-, two- and three- dimensional supramolecular architectures are available because multidentate dipyrrin derivatives can be easily obtained through chemical modifications of the dipyrrin skeleton. Last we describe the binding ability of the fluorine atoms in BODIPY to cationic guests to create a functional response to an external stimulus.