First detection of the Cs symmetric isomer of carbon hexaoxide (CO6) at 10 K

Carbon oxides of the form COn (n = 2–8) have long been known as important molecules in atmospheric and solid state chemical reactions. Here, we report on the first infrared spectroscopic detection of the cyclic (Cs) isomer of carbon hexaoxide (12C16O6) via its ν1 vibrational mode centered around 1876 cm−1 under matrix isolation conditions; the identification of the 12C18O6, 13C16O6, and 13C18O6, isotopologues supported by ab initio calculations confirm the assignments. We also discuss possible formation routes of this molecule.