Far-Infrared Spectroscopy of Neutral Coronene, Ovalene, and Dicoronylene

Here we report the first far-IR (FIR) matrix-isolated spectra of the neutral polycyclic aromatic hydrocarbon (PAH) molecules coronene, ovalene, and dicoronylene. The experimental spectra covered the 650–100 cm −1 (15.385–100 μm) range and the theoretical spectra covered the 650–10 cm −1 (15.385–1000 μm) range. The experimentally measured values are in excellent agreement with theoretical values. The fundamental differences between the skeletal or drumhead modes of the FIR and the group vibrational modes of the mid-IR are discussed and detailed descriptions of the FIR vibrational modes are given.