The Infrared Spectrum of Pyrene Anion in the CH Stretching Region

In this work, we report the infrared spectrum of pyrene anion, measured using messenger tagging with up to three Ar atoms. We assign the spectrum using density functional theory and vibrational perturbation theory. We discuss our results in the context of computed and experimental spectra from the literature as well as recent observations from astronomical sources, showing that PAH anions could contribute to the strong infrared emission bands at 3.29 micrometers from carbon rich regions of space.