Tetrafluorenofulvalene (TFF) defies conventional rules of bond strength in organic chemistry. In particular, the central alkene bond of TFF becomes stronger in the quintet state and in the tetraanion. These changes arise from the unusual interplay between the twist, aromaticity and spin pairing in the π-electron system of TFF.
- Bibek Prajapati
- Madan D. Ambhore
- Marcin Stępień