As the first example of expanded heteroporphyrins with heteroatoms at meso-positions, 5,20-dithiahexaphyrins and 5,20-diazahexaphyrins were synthesized via nucleophilic substitution reactions of α,α′-dibromotripyrrin as the key step. While 5,20-dithiahexaphyrins are practically nonaromatic, 5,20-diazahexaphyrins show weakly antiaromatic characters and can be cleanly converted into aromatic 5,20-diazahexaphyrins upon oxidation with PbO2, demonstrating distinct aromaticity switching with maintenance of dumbbell-like conformations.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry