FTMW and millimeter wave spectroscopy of benzanthrone

► Jet cooled pure rotational spectrum of benzanthrone, a 4 ring oxygenated polyaromatic hydrocarbon. ► Sample vaporized by nozzle heating or laser ablation. ► An accurate set of experimental rotational and centrifugal distortion constants. ► B3LYP/6-311+G** predicted constants reliably guide the spectral search.