Fusing Treatment of Pentacenes: Toward Giant Graphene-Like Molecule

To synthesize large-size polycyclic aromatic hydrocarbons that will be treated as model graphene material, we tried to fuse pentacenes at high temperatures under vacuum. Using mass spectroscopy and elemental analysis, we found that the sample recovered from the fusing reaction included a considerable number of dimers of pentacenes, the main component of which was peripentacene. We investigated the dimer phase by spectroscopic measurements such as X-ray diffraction (XRD), Raman scattering and infrared absorption (FT-IR). In addition, we compared the observed electronic spectroscopic data of the dimer phase and the partial electron density of states of peripentacene derived from the first principle calculations. The observed spectra were well reproduced by the calculations.