For the last ten years, ring-shaped pi-conjugated macrocycles (so called nanorings) possessing radially directed pi-orbitals have been subject to intense research. For all nanorings, defining the evolution of their structural and electronic properties as a function of the ring size is a crucial step in the understanding of these new generations of p-conjugated systems and their possible applications. This work reports the synthesis and the study of the first examples of cyclofluorenes possessing five constituting fluorene units. By comparison with a shorter analogue, -cyclofluorene, we show how the electronic properties of -cyclofluorenes are drastically different from those of -cyclofluorenes, highlighting the key role played by the ring size in the cyclofluorene family.
This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 699648 (FRODO, Cassandre Quinton).
Cyril Poriel, Univ Rennes, CNRS, ISCR-6226, F-35000 Rennes, France
[n]-Cyclo-9,9-dibutyl-2,7-fluorene (n=4,5): Nanoring size influence in carbon bridged cyclo-para-phenylenes
Lambert Sicard, Fabien Lucas, Olivier Jeannin, Pierre-Antoine Bouit, Joëlle Rault-Berthelot, Cassandre Quinton, Cyril Poriel*
Angew. chem. Int. Ed., 2020, in press
The artwork has been performed by Jean-Francois Bergamini
Published on 2020/07/02