Astrochemistry articles from across Nature Portfolio

CO₂ is prominent in the Earth’s and exoplanetary atmospheres, but its excited state photochemistry is not yet fully understood. Here the authors identify gradual quenching of the diffuse vibrational structure in supercritical CO₂ electronic spectra under pressures up to 137 bar.

Cyanide anions exist in interstellar space, but the vibrationally or electronically excited states above the electron autodetachment threshold of CN^- are assumed to have no contributions to cosmic CN^-. Here, the authors report long-lived, superexcited CN^- from the dissociative electron attachment to cyanogen bromide.

H₃⁺ has great astronomical significance, but its formation mechanisms are not fully understood. Here a combined experimental and theoretical study of H₃⁺ formation dynamics from ethane dications shows that roaming occurs at a much longer timescale than the transition state, and is accompanied by nuclear motion of larger amplitudes.

Polycyclic aromatic hydrocarbons (PAHs) are present in the interstellar medium but their origin is unclear. Here the authors investigate large PAH formation from smaller PAHs in a plasma jet by mass-selective IR and UV laser spectroscopy, uncovering diacetylene radical addition as formation mechanism.