Researchers from the NanoSciences Group at CEMES have been able to solve this problem by designing chemically stable, non-planar and soluble precursors which allows their synthesis and characterization by classical methods of organic chemistry (in fifteen synthesis steps in total).
These precursors can be converted to starphene simply by heating either in the solid phase or on an ultra-high vacuum surface or by irradiating in ultra-violet in a solvent frozen at a few degrees Kelvin. The electronic structure and optical properties of these molecules have been studied in collaboration with teams of microscopists from the DIPC in San Sebastian (Spain), photophysicists from the Academy of Sciences in Warsaw (Poland) and a theorist from the university. from Hokkaido (Japan).
Caption : (a) High-Resolution Scanning Tunneling Microscopy image (tip functionalized with a CO Molecule-STM image of a starphene. (b) dI/dV point spectra on starphene showing various resonances marked with dashed lines. The inset marks the positions at which each of the spectra are taken, two on the molecule and one on the substrate as reference. (c) and (d) Constant height dI/dV images of a starphene recorded with a Cl tip at the energy of the lowest unoccupied and highest occupied states, respectively. (e) and (f) Calculated wavefunctions of the HOMO and LUMO of free-standing starphene.
Contact : André Gourdon, andre.gourdon [at] cemes.fr
Publication : A Large Starphene Comprising Pentacene Branches
Jan Holec, Beatrice Cogliati, James Lawrence, Alejandro Berdonces-Layunta, Pablo Herrero, Yuuya Nagata, Marzena Banasiewicz, Boleslaw Kozankiewicz, Martina Corso, Dimas G. de Oteyza, Andrej Jancarik* and André Gourdon*
Angew. Chem. Int. Ed.Eng. (2021) https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202016163