Photolysis of Astrophysically Relevant Acrylonitrile: A Matrix Experimental Study

This report documents the photochemical study of H₂CC­(H)­CN (acrylonitrile) trapped in low-temperature argon matrices and irradiated with a microwave-discharge hydrogen-flow lamp (λ > 120 nm). We succeeded in identifying H₂CC­(H)­NC (isoacrylonitrile) as a photoproduct. HC₃N (cyanoacetylene), C₂H₂:HCN (acetylene:hydrogen cyanide), and C₂H₂:HNC (acetylene:hydrogen isocyanide) complexes, which are molecules detected in molecular clouds or in the Titan atmosphere, were also identified. No imine product was observed, but other compounds coming from the HC₃N photolysis have been found. Fourier transform infrared measurements and ²H substitution experiments coupled with density functional theory calculations (B3LYP/6-31G**) were performed to confirm the spectral assignments of the photochemical products and intermediate species