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.
Bibliographical noteFunding Information:
The work at Kyoto was supported by JSPS KAKENHI Grant Numbers (JP18K14199, JP16H00909 and JP18H03910). M. U. acknowledges a JSPS Fellowship for Young Scientists. T. T. thanks financial support from the TOBEMAKI Scholarship Foundation, Murata Science Foundation and Izumi Science and Technology Foundation. The work at Yonsei University was supported by Strategic Research (NRF2016R1E1A1A01943379) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry