Low-temperature nitrogen-bearing polycyclic aromatic hydrocarbon formation routes validated by infrared spectroscopy

Polycyclic aromatic hydrocarbons (PAHs) are abundant in many regions of the Universe, representing a major reservoir for cosmic carbon. However, their formation pathways cold space remain elusive. Recent astronomical detections show that current astrochemical models drastically underestimate abundance molecules and suggest additional such as ion–molecule reactions need to be considered. Here we reveal efficient low-temperature towards nitrogen-containing PAHs via exothermic pyridine+ acetylene reactions. The experimental approach combines kinetics with spectroscopic probing unambiguously identifies key reaction intermediates final PAH product quinolizinium+, structure is thought contribute 6.2 μm interstellar emission feature. This study not only provides competing relevant chemistry medium Titan’s atmosphere, but also delivers information verify in-silico potential energy surfaces, infrared observations. nitrogen-bearing polycyclic (N-PAHs) prompt questions about how these form at low temperatures. combination kinetic studies spectroscopy reveals an route from monocyclic N-PAHs.