Efficient Photogeneration: A Means of Synthesising Highly Reactive Molecules
In the 90’s a theoretical study proposed the idea that the existence of surface localized photoelectrons can be relevant for on-surface photochemistry of diatomic molecules. In this work we show that the same idea is extensible to long chain molecules where the affinity levels of the molecules are more delocalized. We focus our study on long-chain acenes due to their interesting electronic properties. These molecules have been proposed for carbon-based spintronics or electronic applications for their semiconductor properties. In general, they are difficult to synthesize due to their low solubility and high reactivity. We have deposited α-bisdiketone precursors on graphene grown epitaxially on Ru(0001). The interaction between graphene and Ru(0001) creates a surface resonance that coincides in energy with the n-π* transition of the diketone group. The photoelectrons produced on the Ru(0001) substrate exposing to visible light populate the surface state and are easily transferred by inelastic scattering to the affinity levels of the precursors. The conversion yield is much higher than in other substrates that do not present an unoccupied surface state. These results allow the design of surfaces to improve the efficiency in photochemistry processes opening the door to the efficient synthesis of complex molecules on surfaces.
Ayani, Cosme G. and Pisarra, Michele and Urgel, José I. and Navarro, Juan Jesús and Díaz, Cristina and Hayashi, Hironobu and Yamada, Hiroko and Calleja, Fabian and Miranda, Rodolfo and Fasel, Roman and Martín, Fernando and Vázquez de Parga, Amadeo L.. Efficient photogeneration of nonacene on nanostructured graphene. Nanoscale Horizons. 6, 744 (2022).
Amadeo L. Vázquez de Parga
IMDEA Nanociencia Dissemination and Communication Office
Source: IMDEA Nanociencia