Accurate spectroscopy of polycyclic aromatic compounds: from the rotational spectrum of fluoren-9-one in the millimeter wave region to its infrared spectrum

• Published in: The Journal of chemical physics Vol. 142; no. 2; p. 024317
• Main Authors: Maris, Assimo, Calabrese, Camilla, Melandri, Sonia, Blanco, Susana
• Format: Journal Article
• Language: English
• Published: United States 14.01.2015
• ISSN: 1089-7690
• DOI: 10.1063/1.4905134

The rotational spectrum of fluoren-9-one, a small oxygenated polycyclic aromatic hydrocarbon, has been recorded and assigned in the 52-74.4 GHz region. The determined small negative value of the inertia defect (-0.3 u Å(2)) has been explained in terms of vibrational-rotational coupling constants calculated at the B3LYP/cc-pVTZ level of theory. Vibrational anharmonic analysis together with second-order vibrational perturbation theory approximation was applied both to fluorenone and its reduced form, fluorene, to predict the mid- and near-infrared spectra. The data presented here give precise indication on the fluorenone ground state structure, allow for an accurate spectral characterization in the millimeter wave and infrared regions, and hopefully will facilitate extensive radio astronomical searches with large radio telescopes.