Hydrogenation of Hexa--hexabenzocoronene: An Entry to Nanographanes and Nanodiamonds.

The fabrication of atomically precise nanographanes is a largely unexplored frontier in carbon-sp nanomaterials, enabling potential applications in phononics, photonics and electronics. One strategy is the hydrogenation of prototypical nanographene monolayers and multilayers under vacuum conditions. Here, we study the interaction of atomic hydrogen, generated by a hydrogen source and hydrogen plasma, with hexa--hexabenzocoronene on gold using integrated time-of-flight mass spectrometry, scanning tunneling microscopy and Raman spectroscopy. Density functional tight-binding molecular dynamics is employed to rationalize the conversion to sp carbon atoms. The resulting hydrogenation of hexa--hexabenzocoronene molecules is demonstrated computationally and experimentally, and the potential for atomically precise hexa--hexabenzocoronene-derived nanodiamond fabrication is proposed.